P0989 Transmission Fluid Pressure Switch/Sensor E Circuit Low

What does it mean?

This generic powertrain/engine diagnostic code generally applies to all OBD-II equipped vehicles, including but not limited to Chevrolet, Acura, Honda, Saturn, Jeep, Toyota, etc.

The Transmission Fluid Pressure Sensor/Switch (TFPS) is typically found attached to the side of the valve body inside the transmission, although it may sometimes be found screwed into the side of the transmission case/body itself.

The TFPS converts mechanical transmission pressures into an electrical signal for the Powertrain Control Module (PCM) or Transmission Control Module (TCM). Typically, the PCM/TCM will then inform other controllers using the vehicle’s data communication bus.

The PCM/TCM receives this voltage signal to determine the transmission operating pressure or when a change occurs. This code is set if this “E” input does not match the normal operating voltages stored in the PCM/TCM memory. This may also be due to internal mechanical problems inside the transmission. Refer to a vehicle-specific repair manual to determine what the “E” circuit is for your particular vehicle.

P0989 is typically an electrical circuit issue (TFPS sensor circuit). This cannot be ignored during the troubleshooting phase, especially when dealing with an intermittent problem.

Troubleshooting steps may vary depending on the manufacturer, TFPS sensor type, and wire colors.

Related “E” Transmission Fluid Pressure Sensor circuit codes:

P0987 Transmission Fluid Pressure Sensor/Switch “E”
P0988 Transmission Fluid Pressure Sensor/Switch “E” Circuit Range/Performance
P0990 Transmission Fluid Pressure Sensor/Switch “E” High
P0991 Transmission Fluid Pressure Sensor/Switch “E” Circuit Intermittent

Code Severity and Symptoms

The severity depends on the circuit where the failure occurred. Since this is an electrical failure, the PCM/TCM may compensate to some extent. The failure may mean the PCM/TCM alters transmission shifting if it is electronically controlled.

Symptoms of a P0989 engine code may include:

Malfunction Indicator Light illuminated
Change in shift quality
Vehicle starts in 2nd or 3rd gear (limp mode)

Causes

Typically, the causes for this code to set are:

Short to ground in the signal circuit to the TFPS sensor – possible
Failed/shorted TFPS sensor – probable
Failed PCM – unlikely (programming required after replacement)

Diagnostic and Repair Procedures

A good starting point is always to check the Technical Service Bulletins (TSBs) for your particular vehicle. Your issue may be a known problem with a known fix published by the manufacturer and can save you time and money when diagnosing.

Next, locate the Transmission Fluid Pressure Sensor/Switch (TFPS) on your particular vehicle. The TFPS is typically found attached to the side of the valve body inside the transmission, although it is sometimes screwed into the side of the transmission case/body itself. Once located, visually inspect the connector and wiring. Look for chafing, rubbing, bare wires, burns, or melted plastic. Separate the connector and carefully inspect the terminals (the metal parts) inside the connector. See if they look burned or have a greenish tint indicating corrosion, especially if they are attached outside the transmission case. Use electrical contact cleaner and a plastic bristle brush if cleaning the terminals is necessary. Let it dry and apply electrical grease where the terminals make contact.

If you have a scan tool, clear the diagnostic codes from memory and see if the P0989 code returns. If not, the connections were likely your problem.

This is the most common area of concern for this code, as external transmission connections have the highest incidence of corrosion problems.

If the P0989 code returns, we will need to test the TFPS sensor and its associated circuits. With the key off, disconnect the electrical connector from the TFPS sensor. Connect a black wire from the digital voltmeter (DVOM) to the ground or low reference terminal at the TFPS sensor wiring harness connector. Connect the red wire from the digital voltmeter to the signal terminal at the TFPS sensor wiring harness connector. Turn the key to the engine off position. Check manufacturer specifications; the voltmeter should read 12 volts or 5 volts. Wiggle the connections to see if they change. If the voltage is incorrect, repair the power or ground wire or replace the PCM/TCM.

If the previous test was successful, connect one wire of an ohmmeter to the signal terminal of the TFPS sensor and the other wire to the ground or low reference terminal of the sensor. Check manufacturer specifications for sensor resistance to accurately test the resistance to pressure when no pressure is applied to it. Wiggle the Transmission Fluid Pressure Sensor/Switch connector while monitoring the resistance. If the ohmmeter readings do not pass, replace the TFPS.

If all previous tests were successful and you continue to get a P0989, this would most likely indicate a faulty TFPS sensor, although a faulty PCM/TCM cannot be ruled out, nor can internal transmission malfunctions until the TFPS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs/TCMs must be programmed or calibrated according to the vehicle to be installed correctly.

P0990 Transmission Fluid Pressure Sensor/Switch E High

What does it mean?

This generic powertrain/engine diagnostic code generally applies to all OBD-II equipped vehicles, including but not limited to Dodge, Chrysler, Chevrolet, GMC, Acura, Toyota, etc., but seems to be most commonly seen on Honda vehicles.

The PCM/TCM receives this voltage signal to determine the transmission operating pressure or when a change occurs. This code is set if this “E” input does not match the normal operating voltages stored in the PCM/TCM memory. Refer to a vehicle-specific repair manual to determine what the “E” circuit is for your particular vehicle.

P0990 is typically an electrical circuit issue (TFPS sensor circuit). This cannot be ignored in the troubleshooting phase, especially when dealing with an intermittent problem.

Troubleshooting steps may vary depending on the manufacturer, TFPS sensor type, and wire colors.

Related Transmission Fluid Pressure Sensor “E” Circuit Codes:

P0987 Transmission Fluid Pressure Sensor/Switch “E”
P0988 Transmission Fluid Pressure Sensor/Switch “E” Circuit Range/Performance
P0989 Transmission Fluid Pressure Sensor/Switch “E” Low
P0991 Transmission Fluid Pressure Sensor/Switch “E” Circuit Intermittent

Code Severity and Symptoms

Severity depends on which circuit the failure occurred in. Since this is an electrical failure, the PCM/TCM may compensate to some extent. The failure may mean that the PCM/TCM alters transmission shifting if it is electronically controlled.

Symptoms of a P0990 engine code may include:

Malfunction Indicator Lamp illuminated
Change in shift quality
Vehicle starts in 2nd or 3rd gear (limp mode)

Causes

Typically, the causes for this code to set are as follows:

Short to power in the TFPS sensor signal circuit – possible
Open circuit to ground of the TFPS sensor – possible
Failed/shorted internal TFPS sensor – probable
Failed PCM – unlikely (programming required after replacement)

Diagnostic and Repair Procedures

A good example of this would be if there are known power-related codes with P0990, or if there is more than one set of pressure sensor/switch codes. If so, begin your diagnosis with the power-related trouble code or multiple code diagnosis first, as this may be the reason for P0990.

Next, locate the Transmission Fluid Pressure Sensor/Switch (TFPS) on your particular vehicle. The TFPS is typically found attached to the side of the valve body inside the transmission, although it is sometimes screwed into the side of the transmission housing/body itself. Once located, visually inspect the connector and wiring. Look for chafing, rubbing, bare wires, burns, or melted plastic. Disconnect the connector and carefully inspect the terminals (the metal parts) inside the connector. See if they look burned or have a greenish tint indicating corrosion, especially if they are mounted outside the transmission case. Use electrical contact cleaner and a plastic bristle brush if cleaning the terminals is necessary. Allow to dry and apply electrical grease where the terminals make contact.

If you have a scan tool, clear the diagnostic codes from memory and see if the P0990 code returns. If not, the connections were likely your problem.

This is the most common area of concern for this code, as external transmission connections have the highest incidence of corrosion issues.

If the P0990 code returns, we will need to test the TFPS sensor and its associated circuits. With the key off, disconnect the electrical connector from the TFPS sensor. Connect a black wire from the digital voltmeter (DVOM) to the ground or low reference terminal at the TFPS sensor wiring harness connector. Connect the red wire from the digital voltmeter to the signal terminal at the TFPS sensor wiring harness connector. Turn the key to the engine off position. Check manufacturer specifications; the voltmeter should read 12 volts or 5 volts. Wiggle the connections to see if they change. If the voltage is incorrect, repair the power or ground wire or replace the PCM/TCM.

If the previous test was successful, connect one wire of an ohmmeter to the signal terminal of the TFPS sensor and the other wire to the ground or low reference terminal at the sensor. Check manufacturer specifications for sensor resistance to accurately test resistance to pressure when no pressure is applied to it. Wiggle the transmission fluid pressure sensor/switch connector while monitoring the resistance. If the ohmmeter readings do not pass, replace the TFPS.

If all previous tests have passed and you continue to get a P0990, this would most likely indicate a faulty TFPS sensor, although a faulty PCM/TCM cannot be ruled out, nor can internal transmission malfunctions until the TFPS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs/TCMs must be programmed or calibrated to the vehicle in order to be installed correctly.

P0991 Transmission Fluid Pressure Sensor/Switch E Circuit Intermittent

What does it mean?

This generic powertrain/engine diagnostic code generally applies to all vehicles equipped with OBD-II (e.g., GM, Chevrolet, Honda, Toyota, Ford, etc.), but appears more frequently in Nissan vehicles.

The TFPS converts mechanical transmission pressures into an electrical signal for the Powertrain Control Module (PCM) or the Transmission Control Module (TCM). Typically, the PCM/TCM will then inform other controllers using the vehicle’s data communication bus.

The PCM/TCM receives this voltage signal to determine the transmission operating pressure or when a change occurs. This code is set if this “E” input does not match the normal operating voltages stored in the PCM/TCM memory. This can also be due to internal mechanical issues within the transmission. Refer to a vehicle-specific repair manual to determine what the “E” circuit is for your particular vehicle.

P0991 is generally an electrical circuit issue (TFPS sensor circuit), although, as mentioned earlier, this code can also be set due to mechanical problems (internal leaks, cracked or missing control balls in the valve body, low system operating pressure/main line pressure, stuck valve in the valve body). This cannot be ignored during the troubleshooting phase, especially when dealing with an intermittent issue.

Troubleshooting steps may vary depending on the manufacturer, the type of TFPS sensor, and the wire colors.

Related Transmission Fluid Pressure Sensor “E” Circuit Codes:

P0987 Transmission Fluid Pressure Sensor/Switch “E”
P0988 Transmission Fluid Pressure Sensor/Switch “E” Circuit Range/Performance
P0989 Transmission Fluid Pressure Sensor/Switch “E” Low
P0990 Transmission Fluid Pressure Sensor/Switch “E” High

Code Severity and Symptoms

The severity depends on the circuit where the failure occurred. Since it can be an electrical failure or a mechanical failure, the PCM/TCM may compensate to some extent. The failure may mean that the PCM/TCM alters the transmission shift if it is electronically controlled.

Symptoms of a P0991 engine code may include:

Malfunction Indicator Lamp illuminated
Change in shift quality
Vehicle starts in 2nd or 3rd gear (limp mode)

Causes

Typically, the causes for this code to be set are as follows:

Intermittent open in the signal circuit to the TFPS sensor
Intermittent short to voltage in the signal circuit to the TFPS sensor
Intermittent short to ground in the signal circuit to the TFPS sensor
Failed TFPS sensor – likely
Internal mechanical transmission issue – possible
Failed PCM – unlikely (programming required after replacement)

Diagnostic and Repair Procedures

A good example of this would be if there are known codes related to power supply with P0991, or if there is more than one pressure sensor/switch code. If so, start your diagnosis with the power-related error code or multiple code diagnostics first, as this may be the reason for P0991.

Next, locate the Transmission Fluid Pressure Sensor/Switch (TFPS) on your specific vehicle. The TFPS is typically attached to the side of the valve body inside the transmission, although it is sometimes screwed into the side of the transmission case/body itself. Once located, visually inspect the connector and wiring. Look for scratches, rubbing, bare wires, burns, or melted plastic. Disconnect the connector and carefully inspect the terminals (the metal parts) inside the connector. See if they look burnt or have a greenish tint indicating corrosion, especially if they are mounted outside the transmission case. Use an electrical contact cleaner and a plastic-bristled brush if cleaning the terminals is necessary. Let it dry and apply electrical grease where the terminals make contact.

If you have a scan tool, clear the diagnostic codes from the memory and see if the P0991 code returns. If not, the connections were likely your problem.

This is the most common area of concern for this code, as external transmission connections have the highest number of corrosion issues.

If the P0991 code returns, we will need to test the TFPS sensor and its associated circuits. With the key off, disconnect the electrical connector from the TFPS sensor. Connect a black wire from the Digital Volt Ohm Meter (DVOM) to the ground or low reference terminal at the TFPS sensor wiring harness connector. Connect the red wire from the DVOM to the signal terminal at the TFPS sensor wiring harness. Turn the key to the engine off position. Check the manufacturer’s specifications; the voltmeter should read 12 volts or 5 volts. Wiggle the connections to see if they change. If the voltage is incorrect, repair the power or ground wire or replace the PCM/TCM.

If the previous test was successful, connect one wire of an ohmmeter to the signal terminal of the TFPS sensor and the other wire to the ground or low reference terminal of the sensor. Check the manufacturer’s specifications for the sensor’s resistance to accurately test the resistance at pressure when no pressure is applied to it. Wiggle the Transmission Fluid Pressure Sensor/Switch connector while monitoring the resistance. If the ohmmeter readings do not pass, replace the TFPS.

If all previous tests have passed and you continue to get a P0991, this would most likely indicate a failing TFPS sensor, although a faulty PCM/TCM cannot be ruled out, nor can internal transmission malfunctions until the TFPS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs/TCMs must be programmed or calibrated according to the vehicle to be installed correctly.

P0992 Transmission Fluid Pressure Sensor/Switch F Circuit

What does it mean?

This generic powertrain/engine diagnostic code typically applies to all OBD-II equipped vehicles, including but not limited to Nissan, Dodge, Chrysler, Honda, Chevrolet, GMC, Toyota, etc., but it seems to be most commonly seen on Nissan vehicles.

The PCM/TCM receives this voltage signal to determine the transmission operating pressure or when a change occurs. This code is set if this “F” input does not match the normal operating voltages stored in the PCM/TCM memory. This can also be due to internal mechanical problems inside the transmission. Refer to a vehicle-specific repair manual to determine what the “F” circuit is for your particular vehicle.

P0992 is typically an electrical circuit issue (TFPS sensor circuit), although, as mentioned earlier, this code can also be set due to mechanical problems (internal leaks, cracked or missing check balls in the valve body, low system operating pressure/main line pressure, stuck valve in the valve body). This cannot be ignored in the troubleshooting phase, especially when dealing with an intermittent issue.

Troubleshooting steps may vary depending on the manufacturer, the type of TFPS sensor, and the wire colors.

Related “F” Transmission Fluid Pressure Sensor Circuit Codes:

P0993 Transmission Fluid Pressure Sensor/Switch “F” Circuit Range/Performance
P0994 Transmission Fluid Pressure Sensor/Switch “F” Low
P0995 Transmission Fluid Pressure Sensor/Switch “F” High
P0996 Transmission Fluid Pressure Sensor/Switch “F” Circuit Intermittent

Code Severity and Symptoms

The severity depends on the circuit in which the failure occurred. As it is an electrical failure, the PCM/TCM may compensate to some extent. The failure may mean the PCM/TCM alters the transmission shift if it is electronically controlled.

Symptoms of a P0992 engine code may include:

Malfunction Indicator Lamp illuminated
Change in shift quality
Vehicle starts in 2nd or 3rd gear (limp mode)

Causes

Typically, the causes for this code to set are:

Open in the signal circuit to the TFPS sensor – Possible
Short to voltage in the signal circuit to the TFPS sensor – Possible
Short to ground in the signal circuit to the TFPS sensor – Possible
Faulty TFPS sensor – Probable
Internal transmission mechanical problem – Possible
Failed PCM – Unlikely (Programming required after replacement)

Diagnostic and Repair Procedures

A good starting point is always to check the Technical Service Bulletins (TSBs) for your particular vehicle. Your issue may be a known problem with a known fix released by the manufacturer and can save you time and money when diagnosing.

A good example of this would be if there are known power-related codes with P0992, or if there is more than one set of pressure sensor/switch codes. If so, start your diagnosis with the power-related trouble code or the multiple code diagnosis first, as this may be the reason for the P0992.

Next, locate the Transmission Fluid Pressure Sensor/Switch (TFPS) on your particular vehicle. The TFPS is typically found attached to the side of the valve body inside the transmission, although it is sometimes screwed into the side of the transmission case/body itself. Once located, visually inspect the connector and wiring. Look for chafing, rubbing, bare wires, burns, or melted plastic. Separate the connector and carefully inspect the terminals (the metal parts) inside the connector. See if they look burned or have a greenish tint indicating corrosion, especially if they are mounted outside the transmission case. Use electrical contact cleaner and a plastic bristle brush if cleaning the terminals is necessary. Let it dry and apply electrical grease where the terminals make contact.

If you have a scan tool, clear the diagnostic codes from memory and see if the P0992 code returns. If it does not, the connections were likely your problem.

This is the most common area of concern for this code, as external transmission connections have the highest incidence of corrosion problems.

If the P0992 code returns, we will need to test the TFPS sensor and its associated circuits. With the key off, disconnect the electrical connector from the TFPS sensor. Connect a black wire from the Digital Volt Ohm Meter (DVOM) to the ground or low reference terminal at the TFPS sensor harness connector. Connect the red wire from the DVOM to the signal terminal of the TFPS sensor harness connector. Turn the key to the engine off position. Check the manufacturer’s specifications; the voltmeter should read 12 volts or 5 volts. Wiggle the connections to see if they change. If the voltage is incorrect, repair the power or ground wire or replace the PCM/TCM.

If the previous test was successful, connect one wire of an ohmmeter to the signal terminal of the TFPS sensor and the other wire to the ground or low reference terminal of the sensor. Check the manufacturer’s specifications for the sensor resistance to accurately test the resistance to pressure when no pressure is applied to it. Wiggle the Transmission Fluid Pressure Sensor/Switch connector while monitoring the resistance. If the ohmmeter readings do not pass, replace the TFPS.

If all previous tests have passed and you continue to get a P0992, this would most likely indicate a failing TFPS sensor, although a faulty PCM/TCM cannot be ruled out, nor can internal transmission malfunctions until the TFPS sensor has been replaced. If in doubt, seek help from a qualified automotive diagnostician. PCMs/TCMs need to be programmed or calibrated to the vehicle in order to be installed correctly.

P0993 Transmission Fluid Pressure Sensor/Switch, Circuit F Performance Range

What does it mean?

This generic powertrain/engine diagnostic code generally applies to all OBD-II equipped vehicles, including but not limited to Jeep, Dodge, Mazda, Nissan, Honda, GM, etc.

P0993 is generally an electrical circuit issue (TFPS sensor circuit), although, as mentioned earlier, this code can also be set due to mechanical problems (internal leaks, cracked or missing control balls in the valve body, low system operating pressure/main line pressure, stuck valve in the valve body). This cannot be ignored during the troubleshooting phase, especially when dealing with an intermittent issue.

Troubleshooting steps may vary depending on the manufacturer, TFPS sensor type, and wire colors.

Related “F” Transmission Fluid Pressure Sensor Circuit Codes:

P0992 Transmission Fluid Pressure Sensor/Switch “F”
P0994 Transmission Fluid Pressure Sensor/Switch “F” Low
P0995 Transmission Fluid Pressure Sensor/Switch “F” High
P0996 Transmission Fluid Pressure Sensor/Switch “F” Circuit Intermittent

Code Severity and Symptoms

The severity depends on the circuit where the failure occurred. Since it is an electrical failure, the PCM/TCM can compensate to some extent. The failure may mean that the PCM/TCM alters the transmission shift if it is electronically controlled.

Symptoms of a P0993 engine code may include:

Malfunction Indicator Lamp illuminated
Change in shift quality
Vehicle starts in 2nd or 3rd gear (limp mode)

Causes

Typically, the causes for this code to set are as follows:

Open in the signal circuit to the TFPS sensor – possible
Short to voltage in the signal circuit to the TFPS sensor – possible
Short to ground in the signal circuit to the TFPS sensor – possible
Failed TFPS sensor – probable
Internal mechanical transmission problem – possible
Failed PCM – unlikely (programming required after replacement)

Diagnostic and Repair Procedures

A good example of this would be if there are known power-related codes with P0993, or if there is more than one set of pressure sensor/switch codes. If so, start your diagnosis with the power-related trouble code or the multiple code diagnosis first, as this may be the reason for P0993.

Next, locate the Transmission Fluid Pressure Sensor/Switch (TFPS) on your particular vehicle. The TFPS is typically found attached to the side of the valve body inside the transmission, although it is sometimes screwed into the side of the transmission case/body itself. Once located, visually inspect the connector and wiring. Look for chafing, rubbing, bare wires, burns, or melted plastic. Disconnect the connector and carefully inspect the terminals (the metal parts) inside the connector. See if they look burned or have a greenish tint indicating corrosion, especially if they are mounted outside the transmission case. Use electrical contact cleaner and a plastic bristle brush if cleaning the terminals is necessary. Let it dry and apply electrical grease where the terminals make contact.

If you have a scan tool, clear the diagnostic codes from the memory and see if the P0993 code returns. If it does not, the connections were likely your problem.

This is the most common area of concern for this code, as external transmission connections have the highest number of corrosion issues.

If the P0993 code returns, we will need to test the TFPS sensor and its associated circuits. With the key off, disconnect the electrical connector from the TFPS sensor. Connect a black wire from the Digital Volt Ohm Meter (DVOM) to the ground or low reference terminal at the TFPS sensor wiring harness connector. Connect the red wire from the DVOM to the signal terminal at the TFPS sensor wiring harness connector. Turn the key to the engine off position. Check the manufacturer’s specifications; the voltmeter should read 12 volts or 5 volts. Wiggle the connections to see if they change. If the voltage is incorrect, repair the power or ground wire or replace the PCM/TCM.

If the previous test was successful, connect one wire of an ohmmeter to the signal terminal of the TFPS sensor and the other wire to the ground or low reference terminal of the sensor. Check the manufacturer’s specifications for the sensor’s resistance to accurately test the resistance to pressure when no pressure is applied to it. Wiggle the Transmission Fluid Pressure Sensor/Switch connector while monitoring the resistance. If the ohmmeter readings do not pass, replace the TFPS.

If all previous tests have passed and you continue to get a P0993, this would most likely indicate a faulty TFPS sensor, although a faulty PCM/TCM cannot be ruled out, nor can internal transmission malfunctions until the TFPS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs/TCMs need to be programmed or calibrated to the vehicle in order to be installed correctly.

P0994 Transmission Fluid Pressure Sensor/Switch F Low Circuit

What does it mean?

This generic powertrain/engine diagnostic code typically applies to all OBD-II equipped vehicles, including but not limited to Chevrolet, Acura, Honda, Saturn, Jeep, Toyota, etc.

The PCM/TCM receives this voltage signal to determine the transmission operating pressure or when a change occurs. This code is set if this “F” input does not match the normal operating voltages stored in the PCM/TCM memory. This may also be due to internal mechanical issues within the transmission. Refer to a vehicle-specific repair manual to determine what the “F” circuit is for your particular vehicle.

P0994 is typically an electrical circuit issue (TFPS sensor circuit). This cannot be ignored during the troubleshooting phase, especially when dealing with an intermittent problem.

Troubleshooting steps may vary depending on the manufacturer, TFPS sensor type, and wire colors.

Related Transmission Fluid Pressure Sensor “F” Circuit Codes:

P0992 Transmission Fluid Pressure Sensor/Switch “F”
P0993 Transmission Fluid Pressure Sensor/Switch “F” Circuit Range/Performance
P0995 Transmission Fluid Pressure Sensor/Switch “F” High
P0996 Transmission Fluid Pressure Sensor/Switch “F” Circuit Intermittent

Code Severity and Symptoms

Symptoms of a P0994 engine code may include:

Malfunction Indicator Light illuminated
Change in shift quality
Vehicle starts in 2nd or 3rd gear (limp mode)

Causes

Typically, the causes for this code to set are:

Short to ground in the signal circuit to the TFPS sensor – possible
Failed/short-circuited TFPS sensor – probable
Failed PCM – unlikely (programming required after replacement)

Diagnostic and Repair Procedures

Next, locate the Transmission Fluid Pressure Sensor/Switch (TFPS) on your particular vehicle. The TFPS is typically found attached to the side of the valve body inside the transmission, although it is sometimes screwed into the side of the transmission case/body itself. Once located, visually inspect the connector and wiring. Look for chafing, rubbing, bare wires, burns, or melted plastic. Separate the connector and carefully inspect the terminals (the metal parts) inside the connector. See if they look burned or have a greenish tint indicating corrosion, especially if they are attached outside the transmission case. Use electrical contact cleaner and a plastic bristle brush if cleaning the terminals is necessary. Let dry and apply electrical grease where the terminals make contact.

If you have a scan tool, clear the diagnostic codes from memory and see if the P0994 code returns. If not, the connections were likely your problem.

This is the most common area of concern for this code, as external transmission connections have the highest incidence of corrosion issues.

If the P0994 code returns, we will need to test the TFPS sensor and its associated circuits. With the key off, disconnect the electrical connector from the TFPS sensor. Connect a black wire from the digital voltmeter (DVOM) to the ground or low reference terminal at the TFPS sensor wiring harness connector. Connect the red wire from the digital voltmeter to the signal terminal at the TFPS sensor wiring harness connector. Turn the key to the engine off position. Check manufacturer specifications; the voltmeter should read 12 volts or 5 volts. Wiggle the connections to see if they change. If the voltage is incorrect, repair the power or ground wire or replace the PCM/TCM.

If the previous test was successful, connect one wire of an ohmmeter to the signal terminal of the TFPS sensor and the other wire to the ground or low reference terminal of the sensor. Check manufacturer specifications for sensor resistance to accurately test resistance to pressure when no pressure is applied to it. Wiggle the transmission fluid pressure sensor/switch connector while monitoring the resistance. If the ohmmeter readings do not pass, replace the TFPS.

If all previous tests were successful and you continue to get a P0994, this would most likely indicate a faulty TFPS sensor, although a faulty PCM/TCM cannot be ruled out, nor can internal transmission malfunctions until the TFPS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs/TCMs must be programmed or calibrated according to the vehicle to be installed correctly.

P0995 Transmission Fluid Pressure Sensor/Switch F Circuit

What does it mean?

The PCM/TCM receives this voltage signal to determine the transmission’s operating pressure or when a change occurs. This code is set if this “F” input does not match the normal operating voltages stored in the PCM/TCM’s memory. Refer to a vehicle-specific repair manual to determine what the “F” circuit is for your particular vehicle.

P0995 is generally an electrical circuit issue (TFPS sensor circuit). This cannot be ignored in the troubleshooting phase, especially when dealing with an intermittent problem.

Troubleshooting steps may vary depending on the manufacturer, the type of TFPS sensor, and the wire colors.

Related “F” Transmission Fluid Pressure Sensor Circuit Codes:

P0992 Transmission Fluid Pressure Sensor/Switch “F”
P0993 Transmission Fluid Pressure Sensor/Switch “F” Circuit Range/Performance
P0994 Transmission Fluid Pressure Sensor/Switch “F” Low
P0996 Transmission Fluid Pressure Sensor/Switch “F” Circuit Intermittent

Code Severity and Symptoms

The severity depends on the circuit where the failure occurred. As it is an electrical failure, the PCM/TCM may compensate to some extent. The failure could mean the PCM/TCM alters the transmission shifting if it is electronically controlled.

Symptoms of a P0995 engine code may include:

Malfunction Indicator Lamp illuminated
Change in shift quality
Vehicle starts in 2nd or 3rd gear (limp-in mode)

Causes

Typically, the causes for this code to set are as follows:

Short to power in the TFPS sensor signal circuit – possible
Open circuit to ground of the TFPS sensor – possible
Failed/shorted internally TFPS sensor – probable
Failed PCM – unlikely (programming required after replacement)

Diagnostic and Repair Procedures

A good example of this would be if there are known power-related codes with P0995, or if there is more than one set of pressure sensor/switch codes. If so, start your diagnosis with the power-related trouble code or the multiple code diagnosis first, as this may be the reason for the P0995.

Next, locate the Transmission Fluid Pressure Sensor/Switch (TFPS) on your particular vehicle. The TFPS is typically found attached to the side of the valve body inside the transmission, although it is sometimes screwed into the side of the transmission case/body itself. Once located, visually inspect the connector and wiring. Look for chafing, rubbing, bare wires, burns, or melted plastic. Separate the connector and carefully inspect the terminals (the metal parts) inside the connector. See if they look burned or have a greenish tint indicating corrosion, especially if they are attached outside the transmission case. Use an electrical contact cleaner and a plastic bristle brush if cleaning the terminals is necessary. Let it dry and apply electrical grease where the terminals make contact.

If you have a scan tool, clear the diagnostic codes from the memory and see if the P0995 code returns. If it does not, the connections were likely your problem.

This is the most common area of concern for this code, as external transmission connections have the highest number of corrosion issues.

If the P0995 code returns, we will need to test the TFPS sensor and its associated circuits. With the key off, disconnect the electrical connector from the TFPS sensor. Connect a black wire from the Digital Volt Ohm Meter (DVOM) to the ground or low reference terminal at the TFPS sensor wiring harness connector. Connect the red wire from the DVOM to the signal terminal at the TFPS sensor wiring harness connector. Turn the key to the engine off position. Check the manufacturer’s specifications; the voltmeter should read 12 volts or 5 volts. Wiggle the connections to see if they change. If the voltage is incorrect, repair the power or ground wire or replace the PCM/TCM.

If the previous test was successful, connect one wire of an ohmmeter to the signal terminal of the TFPS sensor and the other wire to the ground or low reference terminal at the sensor. Check the manufacturer’s specifications for the sensor’s resistance to accurately test the resistance to pressure when no pressure is applied to it. Wiggle the Transmission Fluid Pressure Sensor/Switch connector while monitoring the resistance. If the ohmmeter readings do not pass, replace the TFPS.

If all previous tests were successful and you continue to get a P0995, this would most likely indicate a faulty TFPS sensor, although a faulty PCM/TCM cannot be ruled out, nor can internal transmission malfunctions until the TFPS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs/TCMs need to be programmed or calibrated to the vehicle in order to be installed correctly.

P0996 Transmission Fluid Pressure Sensor/Switch F, Intermittent Circuit

What does it mean?

This generic powertrain/engine diagnostic code generally applies to all vehicles equipped with OBD-II (e.g., GM, Chevrolet, Honda, Toyota, Ford, etc.), but appears more frequently in Nissan vehicles.

The PCM/TCM receives this voltage signal to determine the transmission’s operating pressure or when a change occurs. This code is set if this “F” input does not match the normal operating voltages stored in the PCM/TCM’s memory. This can also be due to internal mechanical problems within the transmission. Refer to a vehicle-specific repair manual to determine what the “F” circuit is for your particular vehicle.

P0996 is generally an electrical circuit issue (TFPS sensor circuit), although, as mentioned earlier, this code can also be set due to mechanical problems (internal leaks, cracked or missing control balls in the valve body, low system operating pressure/main line pressure, stuck valve in the valve body). This cannot be ignored during the troubleshooting phase, especially when it is an intermittent issue.

Troubleshooting steps may vary depending on the manufacturer, the type of TFPS sensor, and the wire colors.

Related Transmission Fluid Pressure Sensor “F” Circuit Codes:

P0992 Transmission Fluid Pressure Sensor/Switch “F”
P0993 Transmission Fluid Pressure Sensor/Switch “F” Circuit Range/Performance
P0994 Transmission Fluid Pressure Sensor/Switch “F” Low
P0995 Transmission Fluid Pressure Sensor/Switch “F” High

Code Severity and Symptoms

The severity depends on the circuit where the failure occurred. As it can be an electrical failure or a mechanical failure, the PCM/TCM may compensate to some extent. The failure may mean that the PCM/TCM alters the transmission shift if it is electronically controlled.

Symptoms of a P0996 engine code may include:

Malfunction Indicator Lamp illuminated
Change in shift quality
Vehicle starts in 2nd or 3rd gear (limp mode)

Causes

Typically, the causes for this code to set are as follows:

Intermittent open in the signal circuit to the TFPS sensor
Intermittent short to voltage in the signal circuit to the TFPS sensor
Intermittent short to ground in the signal circuit to the TFPS sensor
Failed TFPS sensor – likely
Internal mechanical transmission problem – possible
Failed PCM – unlikely (programming required after replacement)

Diagnostic and Repair Procedures

A good example of this would be if there are known codes related to power supply with P0996, or if there is more than one set of pressure sensor/switch codes. If so, start your diagnosis with the power-related trouble code or the multiple code diagnosis first, as this may be the reason for P0996.

Next, locate the Transmission Fluid Pressure Sensor/Switch (TFPS) on your specific vehicle. The TFPS is typically found attached to the side of the valve body inside the transmission, although it is sometimes screwed into the side of the transmission case/body itself. Once located, visually inspect the connector and wiring. Look for chafing, rubbing, bare wires, burns, or melted plastic. Disconnect the connector and carefully inspect the terminals (the metal parts) inside the connector. See if they look burned or have a greenish tint indicating corrosion, especially if they are mounted on the outside of the transmission case. Use an electrical contact cleaner and a plastic bristle brush if cleaning the terminals is necessary. Let it dry and apply electrical grease where the terminals make contact.

If you have a scan tool, clear the diagnostic codes from the memory and see if the P0996 code returns. If it does not, the connections were likely your problem.

This is the most common area of concern for this code, as external transmission connections have the highest incidence of corrosion issues.

If the P0996 code returns, we will need to test the TFPS sensor and its associated circuits. With the key off, disconnect the electrical connector from the TFPS sensor. Connect a black wire from the Digital Volt Ohm Meter (DVOM) to the ground or low reference terminal at the TFPS sensor wiring harness connector. Connect the red wire from the DVOM to the signal terminal at the TFPS sensor wiring harness connector. Turn the key to the engine off position. Check the manufacturer’s specifications; the voltmeter should read 12 volts or 5 volts. Wiggle the connections to see if they change. If the voltage is incorrect, repair the power or ground wire or replace the PCM/TCM.

If the previous test was successful, connect one wire of an ohmmeter to the signal terminal of the TFPS sensor and the other wire to the ground or low reference terminal of the sensor. Check the manufacturer’s specifications for the sensor’s resistance to accurately test the resistance to pressure when no pressure is applied to it. Wiggle the Transmission Fluid Pressure Sensor/Switch connector while monitoring the resistance. If the ohmmeter readings do not pass, replace the TFPS.

If all previous tests were successful and you continue to get a P0996, this would most likely indicate a faulty TFPS sensor, although a faulty PCM/TCM cannot be ruled out, nor can internal transmission malfunctions until the TFPS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs/TCMs need to be programmed or calibrated to the vehicle to be installed correctly.

P0997 Shift Solenoid “F” Control Circuit Range/Performance

For your transmission to perform a gear shift, a small piston-like device called a solenoid opens or closes to direct pressurized transmission fluid into the correct channel, where it pushes or otherwise moves parts such as clutches or gears. If the F shift solenoid (i.e., the sixth solenoid) does not operate according to the programmed parameters, a DTC P0997 will be stored.

How severe is the code?

The diagnostic code P0997 only triggers when the ECU detects that a shift solenoid is not functioning properly. This can lead to a number of driving issues that will eventually result in a non-functional transmission.

Symptoms

Symptoms of a P0997 include:

The transmission seems to engage
The gearbox will not shift into or out of gear

Causes

There is not enough transmission fluid
The transmission fluid is dirty/thin
Damaged/broken wires
Broken/corroded connectors
Failed shift solenoid

How to diagnose the code?

The first thing to do when trying to determine what is causing an OBDII fault code P0997 is to check the level and condition of the transmission fluid. If it is too low or dirty, the transmission fluid must be changed. If there are no issues with the condition of the transmission fluid, then the wiring and connectors along the transmission wiring harness should be inspected. If no problems are detected there, the shift solenoid itself must be tested.

What repairs will fix P0997?

Service the transmission
Replace or repair damaged wires/connectors
Replace the shift solenoid

P0998 Low Shift Solenoid “F” Control Circuit

A DTC P0998 indicates that the ECU has detected a low voltage signal from the shift solenoid F control circuit. This means the computer is unable to command the activation and deactivation of the solenoid.

How severe is the code?

Most of the time, transmission issues associated with a P0998 diagnostic code start out very minor. But they can worsen to the point where your vehicle is almost impossible to drive.

Symptoms

Symptoms of a P0998 include:

The transmission feels like it’s shaking when shifting gears
The transmission does not shift into gear

Causes

Transmission fluid level is too low
Transmission fluid and filter need to be changed
Damaged/broken wires
Broken/corroded connectors
The shift solenoid has stopped working

How to diagnose the code?

Since the level and condition of the transmission fluid will directly affect the operation of each shift solenoid, this should be the first thing to check when diagnosing a P0998 OBDII fault code. The wiring and connectors along the transmission wiring harness are also a factor. If no issues have been detected so far, the shift solenoid F will need to be directly tested.

What repairs will fix P0998?

Service the transmission
Replace or repair damaged wires/connectors
Replace the shift solenoid