What does it mean?

---

This generic powertrain/engine diagnostic code generally applies to all OBDII-equipped engines, but appears more frequently in certain Chrysler, GM, Ford, Lincoln, Mercury, Kia, Mazda, Mercedes Benz, Infiniti, Nissan, and Subaru vehicles.

The Fuel Level Sensor (FLS) is typically mounted inside the fuel tank, usually on top of the fuel tank module/fuel pump. The FLS converts the mechanical fuel level into an electrical signal for the Powertrain Control Module (PCM). Typically, the PCM will then inform other controllers using the vehicle’s data communication bus.

The PCM receives this voltage signal to determine the amount of fuel in the fuel tank, monitoring fuel usage and thus determining fuel economy. This code is set if this input does not match the normal operating voltages stored in the PCM’s memory, even for a second, as indicated by this diagnostic code. It also examines the voltage signal from the FLS sensor to determine if it is correct at initial key-on.

P0461 could have been set due to mechanical issues (incorrect fuel level rationality; refueling the vehicle with the ignition switch on or even with the engine running can cause this. The fuel level changes too rapidly, which is not normal) or electrical issues (FLS sensor circuit). These cannot be overlooked during the troubleshooting phase, especially when dealing with an intermittent problem.

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

Related fuel level sensor circuit trouble codes include:

P0460 Fuel Level Sensor Circuit Malfunction
P0462 Fuel Level Sensor Circuit Low Input
P0463 Fuel Level Sensor Circuit High Input
P0464 Fuel Level Sensor Circuit Intermittent

Severity and Symptoms

---

The severity depends on the failure. In case of mechanical failure; severe. In case of electrical failure, less severe, which the PCM can compensate for. Compensation usually means the fuel gauge reads empty or full all the time.

Symptoms of a P0461 engine code may include:

Malfunction Indicator Lamp (MIL) illuminated
Perceived decrease in fuel economy
Decreased distance to empty mileage
Incorrect fuel level on the gauge in the instrument cluster – always reads incorrectly

Potential Causes

---

Typically, the causes for this code to set are:

Open in the signal circuit to the FLS sensor – possible
Short to voltage in the signal circuit to the FLS sensor – possible
Short to ground in the signal circuit to the FLS sensor – possible
FLS sensor/sensing arm failing mechanically stuck – probable
PCM failed – unlikely

Diagnostic and Repair Procedures

---

A good starting point is always to search for a Technical Service Bulletin (TSB) for your specific vehicle. The vehicle manufacturer may have a PCM flash/reprogram to cover this issue, and it is worth checking before discovering you’ve taken a long/wrong path.

A good example of this is on Ford products where an aftermarket remote start system was installed. This can cause a false code to be set. There is a TSB covering this topic and it should be followed to properly diagnose this condition. Auxiliary fuel tanks are also covered in this TSB. Gravity-fed tanks are not recommended for use on these systems and when refueling Ford trucks. It is recommended to refill the main tanks with the ignition switch in the off position.

Next, locate the Fuel Level Sensor (FLS) on your specific vehicle. This sensor is typically mounted inside the fuel tank or perhaps even on top of the fuel tank module/fuel pump. 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 burnt or have a greenish tint indicating corrosion. 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 P0461 code returns. If it does not, the connections were likely your problem.

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

If the P0461 code returns, we will need to test the FLS sensor and its associated circuits. With the key off, disconnect the electrical connector from the FLS sensor. Connect a black wire from the Digital Volt Ohm Meter (DVOM) to the ground or low reference terminal at the FLS sensor wiring harness connector. Connect the red wire from the DVOM to the signal terminal at the FLS 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. If the voltage is incorrect, repair the power or ground wire or replace the PCM.

If the previous test was successful, connect an ohmmeter to the signal terminal of the sensor and the other lead to the ground or low reference terminal of the sensor. The ohmmeter reading should not be zero ohms nor infinite. Check the manufacturer’s specifications for the sensor resistance to accurately test the resistance at the fuel level (1/2 tank of fuel might read 80 ohms). If the ohmmeter readings fail, replace the FLS.

If all previous tests were successful and you continue to get a P0461, this would most likely indicate a faulty FLS sensor, although a faulty PCM cannot be ruled out until the FLS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs need to be programmed or calibrated to the vehicle to be installed correctly.

What does it mean?

---

This generic powertrain/engine diagnostic code generally applies to all OBDII-equipped engines but appears more frequently in some Chrysler, GM, Ford, Lincoln, Mercury, Honda/Acura, Kia, Mazda, Mercedes Benz, Mitsubishi, Infiniti, Nissan, and Subaru vehicles.

The Fuel Level Sensor (FLS) is typically mounted in the fuel tank, usually at the top of the fuel tank module/fuel pump. The FLS converts the mechanical fuel level into an electrical signal for the Powertrain Control Module (PCM). Typically, the PCM will then inform other controllers using the vehicle’s data communication bus.

The PCM receives this voltage signal to determine the amount of fuel in the fuel tank, monitoring fuel usage and thus determining fuel economy. This code is set if this input does not match the normal operating voltages stored in the PCM’s memory. It also examines the voltage signal from the FLS sensor to determine if it is correct at the initial key-on.

P0462 is usually set due to electrical issues (FLS sensor circuit). These cannot be overlooked during the troubleshooting phase, especially when dealing with an intermittent problem.

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

Related fuel level sensor circuit fault codes include:

P0460 Fuel Level Sensor Circuit Malfunction
P0461 Fuel Level Sensor Circuit Range/Performance
P0463 Fuel Level Sensor Circuit High Input
P0464 Fuel Level Sensor Circuit Intermittent

Severity and Symptoms

---

The severity is usually not as serious. Because it is an electrical failure, the PCM can compensate for it. Compensation typically means the fuel gauge reads empty or full all the time.

Symptoms of a P0462 engine code may include:

Malfunction Indicator Lamp (MIL) illuminated
Perceived decrease in fuel economy
Reduced distance to empty mileage
Incorrect fuel level on the gauge in the instrument cluster – always reads incorrectly

Potential Causes

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

Short to ground in the signal circuit to the FLS sensor – possible
Failed FLS sensor/internal short circuit – likely
Failed PCM – unlikely

Diagnostic and Repair Procedures

---

A good starting point is always to search for a Technical Service Bulletin (TSB) for your specific vehicle. The vehicle manufacturer may have a PCM flash/reprogram to address this issue, and it is worth checking before discovering you’ve taken a long/wrong path.

A good example of this is on Ford products where an aftermarket remote start system has been installed. This can cause a false code to set. There is a TSB covering this topic and it should be followed to properly diagnose this condition. Auxiliary fuel tanks are also covered in this TSB. Gravity-fed tanks are not recommended for use on these systems and when refueling Ford trucks. It is recommended to fill the main tanks with the ignition switch in the off position.

Next, locate the Fuel Level Sensor (FLS) on your specific vehicle. This sensor is usually mounted in the fuel tank or perhaps even at the top of the fuel tank module/fuel pump. 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. Use electrical contact cleaner and a plastic-bristled brush if terminal cleaning 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 P0462 code returns. If it does not, the connections were likely your problem.

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

If the P0462 code returns, we will need to test the FLS sensor and its associated circuits. With the key off, disconnect the electrical connector from the FLS sensor. Connect a black wire from the Digital Volt Ohm Meter (DVOM) to the ground or low reference terminal at the FLS sensor wiring harness connector. Connect the red wire from the DVOM to the signal terminal at the FLS 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. If the voltage is incorrect, repair the power or ground wire or replace the PCM.

If the previous test was successful, connect one wire of an ohmmeter to the signal terminal of the FLS sensor and the other wire to the ground or low reference terminal of the sensor. The ohmmeter reading should not be zero ohms nor infinite. Check the manufacturer’s specifications for sensor resistance to accurately test the resistance at the fuel level (1/2 tank of fuel might read 80 ohms). If the ohmmeter readings do not pass, replace the FLS.

If all previous tests were successful and you continue to get a P0462, this would most likely indicate a faulty FLS sensor, although a faulty PCM cannot be ruled out until the FLS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs need to be programmed or calibrated to the vehicle to be installed correctly.

What does it mean?

---

This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to OBD-II equipped vehicles. Although generic, specific repair steps may vary by make/model.

The fuel level sensor (sender) is located in the fuel tank, typically integrated into the fuel pump module. Usually, they cannot be replaced without replacing the fuel pump module, though there are exceptions. A float attached to an arm moves along a resistor that is grounded to the tank, chassis, or has a dedicated ground circuit. Voltage is supplied to the sender, and the ground path changes based on the fuel level. The voltage amount depends on the system, but 5 volts is not uncommon.

When the fuel level changes, the float moves the arm and alters the ground resistance, which varies the voltage signal. This signal may go to a fuel pump computer module or directly to the instrument cluster module. Depending on the system, the fuel pump computer module may only monitor the ground resistance and then relay fuel level information to the dashboard. If the fuel level signal to the fuel pump module (or instrument cluster module or PCM) exceeds 5 volts for a specific duration, the module monitoring the fuel level circuit will log this fault code.

Related fuel level sensor circuit fault codes include:

P0460 Fuel Level Sensor Circuit Malfunction
P0461 Fuel Level Sensor Circuit Range/Performance
P0462 Fuel Level Sensor Circuit Low Input
P0464 Fuel Level Sensor Circuit Intermittent

Symptoms

---

Symptoms of a P0463 DTC may include:

MIL (Malfunction Indicator Lamp) illumination
Fuel gauge may fluctuate abnormally or read empty or full
Low fuel light may illuminate and trigger an alarm

Causes

Potential causes of a P0463 code include:

Signal circuit to fuel sender is open or shorted to B+ (battery voltage)
Ground circuit is open, or ground path may have high resistance due to rust or missing ground strap on fuel tank
Damage to the fuel tank could cause issues in the fuel level circuit
There is an open in the fuel lever sensor resistor to ground
Instrument cluster may be faulty
Less likely is the possibility of a failed PCM, BCM, or fuel pump computer module

Possible Solutions

---

Fuel pump senders typically last the life of the fuel pump. So, if you have this code, perform a visual inspection of the fuel tank and wiring harness. Look for tank damage indicating an impact that may have damaged the fuel pump or sender. Check for a missing ground strap or rusty ground where the fuel tank connects to the chassis. Ensure the wiring harness connector is not damaged. Repair as needed. Determine the type of system you have and verify that fuel level sensor voltage is present at the fuel pump wiring harness. If not, repair the open or shorted wire.

Performing a voltage drop test on the ground circuit can determine if there is a high-resistance path in the ground circuit. You can do this using a voltmeter by connecting one lead to the battery ground terminal and the other to the fuel level sensor ground in the tank. Turn the key (preferably with the engine running). Ideally, it should be 100 millivolts or less (0.1 volt). Anything close to 1 volt indicates a current or developing issue. Repair/clean the fuel level sensor ground as needed. It is not impossible for the instrument cluster to have failed internally or on the circuit board (if applicable). These are very difficult for a layperson to test. But if you have access to a wiring diagram, you may be able to remove the cluster and see the damaged circuit if it’s on the circuit board; otherwise, you’ll need a scan tool that communicates with the instrument cluster.

A simple way to test the fuel level circuit is to provide a good ground to the fuel level sensor at the fuel tank connector. With the key on, the fuel gauge should go to one extreme or the other. Completely removing the ground path should cause the opposite. If the gauge responds, you know the wiring supplying voltage and ground to the fuel level sensor is good, and the instrument cluster is likely correct. The probable suspect would be the fuel level sensor itself. It may be necessary to remove the fuel tank to access the fuel pump module inside. A PCM or BCM failure is not impossible but highly unlikely. Do not suspect them first.

What does it mean?

---

This generic powertrain/engine diagnostic code generally applies to all OBDII-equipped engines but appears more frequently in certain Hyundai, Infiniti, Isuzu, Kia, Mazda, Mercedes Benz, Nissan, and Subaru vehicles.

The Fuel Level Sensor (FLS) is typically mounted inside the fuel tank, usually at the top of the fuel tank module/fuel pump. The FLS converts the mechanical fuel level into an electrical signal for the Powertrain Control Module (PCM). Typically, the PCM will then inform other controllers using the vehicle’s data communication bus.

The PCM receives this voltage signal to determine the amount of fuel in the fuel tank, monitoring fuel usage and thus determining fuel economy. This code is set if this input does not match the normal operating voltages stored in the PCM’s memory, even for a second, as indicated by this diagnostic code. It also checks the voltage signal from the FLS sensor to determine if it is correct at initial key-on.

P0464 could have been set due to mechanical issues (incorrect fuel level rationality; refueling the vehicle with the ignition switch on or even with the engine running can cause this. The fuel level changes too rapidly, which is not normal) or electrical issues (FLS sensor circuit). These cannot be overlooked during the troubleshooting phase, especially when dealing with an intermittent problem.

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

Related fuel level sensor circuit fault codes include:

P0460 Fuel Level Sensor Circuit Malfunction
P0461 Fuel Level Sensor Circuit Range/Performance
P0462 Fuel Level Sensor Circuit Low Input
P0463 Fuel Level Sensor Circuit High Input

Severity and Symptoms

---

Severity depends on the failure. In case of mechanical failure; severe. In case of electrical failure, less severe, which the PCM can compensate for. Compensation usually means the fuel gauge reads empty or full all the time.

Symptoms of a P0464 engine code may include:

Malfunction Indicator Lamp (MIL) illuminated
Perceived decrease in fuel economy
Reduced distance to empty mileage
Incorrect fuel level on the gauge in the instrument cluster – always reads incorrectly

Potential Causes

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

Intermittent open in the signal circuit to the FLS sensor – possible
Intermittent short to voltage in the signal circuit to the FLS sensor – possible
Intermittent short to ground in the signal circuit to the FLS sensor – possible
Failed FLS sensor/float arm mechanically stuck – likely
Failed PCM – unlikely

Diagnostic and Repair Procedures

---

A good starting point is always to search for a Technical Service Bulletin (TSB) for your specific vehicle. The vehicle manufacturer may have a PCM flash/reprogram to address this issue, and it is worth checking before discovering you’ve taken a long/wrong path.

Next, locate the Fuel Level Sensor (FLS) on your specific vehicle. This sensor is typically mounted inside the fuel tank or perhaps even at the top of the fuel tank module/fuel pump. 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. Use electrical contact cleaner and a plastic-bristled brush if terminal cleaning 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 P0464 code returns. If it does not, the connections were likely your problem.

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

If the P0464 code returns, we will need to test the FLS sensor and its associated circuits. With the key off, disconnect the electrical connector from the FLS sensor. Connect a black wire from the Digital Voltmeter (DVOM) to the ground or low reference terminal at the FLS sensor wiring harness connector. Connect the red wire from the Digital Voltmeter to the signal terminal at the FLS 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.

If the previous test was successful, connect one wire of an ohmmeter to the signal terminal of the FLS sensor and the other wire to the ground or low reference terminal of the sensor. The ohmmeter reading should not be zero ohms nor infinite. Check the manufacturer’s specifications for sensor resistance to accurately test the resistance at the fuel level (1/2 tank of fuel might read 80 ohms). Wiggle the fuel level sensor connector while monitoring the resistance. If the ohmmeter readings do not pass, replace the FLS.

If all previous tests have passed and you continue to get a P0464, this would most likely indicate a faulty FLS sensor, although a faulty PCM cannot be ruled out until the FLS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs need to be programmed or calibrated to the vehicle to be installed correctly.

What does it mean?

---

This generic powertrain/engine diagnostic code can generally apply to all OBDII-equipped engines but appears more frequently in some Mercedes Benz vehicles.

The Purge Flow Sensor (PFS) is typically mounted in the evaporative fuel system, also known as the charcoal canister, near the fuel tank or possibly even in the upper part of the fuel tank module/fuel pump. The PFS converts EVAP system pressure into an electrical signal for the Powertrain Control Module (PCM).

The PCM receives this voltage signal to determine the amount of fuel it will put into the engine as well as the fuel entering the intake manifold of the EVAP system. This code is set if this input does not match the normal engine operating conditions stored in the PCM’s memory, even for a second, as shown by this diagnostic code. It also examines the voltage signal from the PFS sensor to determine if it is correct at the initial key-on.

P0465 could have been set due to mechanical issues (usually EVAP system mechanical problems) or electrical issues (PFS sensor circuit). These cannot be overlooked during the troubleshooting phase, especially when dealing with an intermittent problem.

Troubleshooting steps may vary depending on the manufacturer, PFS sensor type, and wire colors.
Severity and Symptoms

Severity depends on the failure. In case of mechanical failure; severe. In case of electrical failure, less severe, which the PCM can adequately compensate for.

Symptoms of a P0465 engine code may include:

Malfunction Indicator Light (MIL) illuminated
Decreased fuel economy

Potential Causes

---

Typically, the causes for this code to set are:

Open in the signal circuit to the PFS sensor – possible
Short to voltage in the signal circuit to the PFS sensor – possible
Short to ground in the signal circuit to the PFS sensor – possible
Open in power or ground at the PFS sensor – possible
Failed PFS sensor – probable
Failed PCM – unlikely

Diagnostic and Repair Procedures

---

A good starting point is always to search for a Technical Service Bulletin (TSB) for your specific vehicle. The vehicle manufacturer may have a PCM flash/reprogramming to cover this issue, and it’s worth checking before discovering you’ve taken a long/wrong path.

Next, locate the purge flow sensor on your specific vehicle. This sensor is typically mounted in the evaporative fuel system, also known as the charcoal canister, near the fuel tank or possibly even at the top of the fuel tank module/fuel pump. Once located, visually inspect the connector and wiring. Look for scratches, 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. Use electrical contact cleaner and a plastic bristle brush if terminal cleaning 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 P0465 code returns. If not, the connections were probably your problem.

If the P0465 code returns, we will need to test the PFS sensor and its associated circuits. With the key off, disconnect the electrical connector from the PFS sensor. Connect a black wire from the digital voltmeter to the ground terminal at the PFS sensor wiring harness connector. Connect the red wire from the digital voltmeter to the power terminal at the PFS sensor wiring harness connector. Turn the key to engine off. Check manufacturer specifications; the voltmeter should read 12 volts or 5 volts. If not, repair the power or ground wire or replace the PCM.

If the previous test passes, we will need to test the signal wire. With the connector still disconnected, move the red voltmeter wire from the power wire terminal to the signal wire terminal. The voltmeter should now read 5 volts. If not, repair the signal wire or replace the PCM.

If all previous tests pass and you continue to get a P0465, this would most likely indicate a faulty PFS sensor, although a faulty PCM cannot be ruled out until the PFS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs need to be programmed or calibrated according to the vehicle to be installed correctly.

What does it mean?

---

This generic powertrain/engine diagnostic code can generally apply to all OBDII-equipped engines but appears more frequently in certain Mercedes Benz vehicles.

The Purge Flow Sensor (PFS) is typically mounted in the evaporative fuel system, also known as the charcoal canister, near the fuel tank or possibly even in the top of the fuel tank module/fuel pump. The PFS converts EVAP system pressure into an electrical signal for the Powertrain Control Module (PCM).

The PCM receives this voltage signal to determine the amount of fuel it will put into the engine as well as the fuel entering the EVAP system intake manifold. This code is set if this input does not match the normal engine operating conditions stored in the PCM’s memory, even for a second, as indicated by this diagnostic code. It also checks the PFS sensor voltage signal to determine if it is correct at initial key-on.

P0466 could have been set due to mechanical issues (typically EVAP system mechanical problems) or electrical issues (PFS sensor circuit). These cannot be overlooked during the troubleshooting phase, especially when dealing with an intermittent issue.

Troubleshooting steps may vary depending on the manufacturer, PFS sensor type, and wire colors.
Severity and Symptoms

---

Severity depends on the failure. In case of mechanical failure: severe. In case of electrical failure: less severe, which the PCM can adequately compensate for.

Symptoms of a P0466 engine code may include:

Malfunction Indicator Lamp (MIL) illuminated
Decreased fuel economy

Potential Causes

Typically, causes for this code to set include:

Open in the signal circuit to the PFS sensor – possible
Short to voltage in the signal circuit to the PFS sensor – possible
Short to ground in the signal circuit to the PFS sensor – possible
Open in power or ground at the PFS sensor – possible
Failed PFS sensor – probable
Failed PCM – unlikely

Diagnostic and Repair Procedures

---

A good starting point is always researching a Technical Service Bulletin (TSB) for your specific vehicle. The vehicle manufacturer may have a PCM flash/reprogramming to address this issue, and it’s worth checking before discovering you’ve taken a long/wrong path.

Next, locate the purge flow sensor on your specific vehicle. This sensor is typically mounted in the evaporative fuel system, also known as the charcoal canister, near the fuel tank or possibly even at the top of the fuel tank module/fuel pump. Once located, visually inspect the connector and wiring. Look for scratches, rubbing, bare wires, burns, or melted plastic. Separate the connector and carefully inspect the terminals (the metal parts) inside the connector. Check if they appear burned or have a greenish tint indicating corrosion. Use electrical contact cleaner and a plastic bristle brush if terminal cleaning 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 P0466 code returns. If not, the connections were likely your problem.

If the P0466 code returns, we’ll need to test the PFS sensor and its associated circuits. With the key off, disconnect the electrical connector from the PFS sensor. Connect a black wire from the digital voltmeter to the ground terminal at the PFS sensor wiring harness connector. Connect the red wire from the digital voltmeter to the power terminal at the PFS sensor wiring harness connector. Turn the key to engine off. Check manufacturer specifications; the voltmeter should read 12 volts or 5 volts. If not, repair the power or ground wire or replace the PCM.

If the previous test passes, we’ll need to test the signal wire. With the connector still disconnected, move the red voltmeter wire from the power wire terminal to the signal wire terminal. The voltmeter should now read 5 volts. If not, repair the signal wire or replace the PCM.

If all previous tests pass and you continue to get a P0466, this would most likely indicate a failing PFS sensor, although a faulty PCM cannot be ruled out until the PFS sensor has been replaced. When in doubt, seek assistance from a qualified automotive diagnostician. PCMs need to be programmed or calibrated to the vehicle to be installed properly.

What does it mean?

---

This generic powertrain/engine diagnostic code can generally apply to all OBDII-equipped engines but appears more frequently in certain Mercedes Benz vehicles.

The Purge Flow Sensor (PFS) is typically mounted in the evaporative fuel system, also known as the charcoal canister, near the fuel tank or possibly even in the top of the fuel tank module/fuel pump. The PFS converts EVAP system pressure into an electrical signal for the Powertrain Control Module (PCM).

The PCM receives this voltage signal to determine the amount of fuel it will put into the engine as well as the fuel entering the EVAP system intake manifold. This code is set if this input does not match the normal engine operating conditions stored in the PCM’s memory, even for a second, as shown by this diagnostic code. It also examines the PFS sensor voltage signal to determine if it is correct at the initial key-on.

P0467 is set when the voltage at the sensor remains below a defined level (usually under 0.3 V) for too long. This code is generally considered an electrical circuit issue.

Troubleshooting steps may vary depending on the manufacturer, PFS sensor type, and wire colors.
Severity and Symptoms

The severity in this case will not be serious. Since it is an electrical failure, the PCM can adequately compensate.

Symptoms of a P0467 engine code may include:

    Malfunction Indicator Lamp (MIL) illuminated
    Decreased fuel economy

Potential Causes

---

Typically, the causes for this code to set are:

    Short to ground in the signal circuit to the PFS sensor – possible
    Short to ground or open in the power circuit to the PFS sensor – possible
    Failed PFS sensor – probable
    Failed PCM – unlikely

Diagnostic and Repair Procedures

---

A good starting point is always to search for a Technical Service Bulletin (TSB) for your specific vehicle. The vehicle manufacturer may have a PCM flash/reprogramming to address this issue, and it is worth checking before discovering you’ve taken a long/wrong path.

Next, locate the purge flow sensor on your specific vehicle. This sensor is typically mounted in the evaporative fuel system, also known as the charcoal canister, near the fuel tank or possibly even at the top of the fuel tank module/fuel pump. Once located, visually inspect the connector and wiring. Look for scratches, rubbing, bare wires, burns, or melted plastic. Separate the connector and carefully inspect the terminals (the metal parts) inside the connector. See if they appear burnt or have a greenish tint indicating corrosion. Use electrical contact cleaner and a plastic-bristled brush if terminal cleaning is needed. 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 P0467 code returns. If not, the connections were likely your problem.

If the P0467 code returns, we will need to test the PFS sensor and its associated circuits. With the key off, disconnect the electrical connector from the PFS sensor. Connect a black wire from the digital voltmeter to the ground terminal at the PFS sensor wiring harness connector. Connect the red wire from the digital voltmeter to the power terminal at the PFS 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. If not, repair the sensor’s power or ground wire or replace the PCM.

If the previous test passes, we will need to test the signal wire. With the connector still disconnected, move the red voltmeter wire from the power wire terminal to the signal wire terminal. The voltmeter should now read 5 volts. If not, repair the signal wire or replace the PCM.

If all previous tests have passed and you continue to get a P0467, this would most likely indicate a failing PFS sensor, although a faulty PCM cannot be ruled out until the PFS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs need to be programmed or calibrated to the vehicle to be installed correctly.

What does it mean?

---

This generic powertrain/engine diagnostic code can generally apply to all OBDII-equipped engines but appears more frequently in some Mercedes Benz vehicles.

The Purge Flow Sensor (PFS) is typically mounted in the evaporative fuel system, also known as the charcoal canister, near the fuel tank or perhaps even in the upper part of the fuel tank module/fuel pump. The PFS converts EVAP system pressure into an electrical signal for the Powertrain Control Module (PCM).

The PCM receives this voltage signal to determine the amount of fuel it will put into the engine as well as the fuel entering the EVAP system’s intake manifold. This code is set if this input does not match the normal engine operating conditions stored in the PCM’s memory, even for a second, as indicated by this diagnostic code. It also checks the PFS sensor’s voltage signal to determine if it is correct at the initial key-on.

P0468 is set when the voltage at the sensor remains above a defined level (usually above 4.8 V) for too long. This code is generally considered an electrical circuit issue.

Troubleshooting steps may vary depending on the manufacturer, PFS sensor type, and wire colors.
Severity and Symptoms

---

The severity in this case will not be serious. Since it is an electrical failure, the PCM can adequately compensate.

Symptoms of a P0468 engine code may include:

Malfunction Indicator Light (MIL) illuminated
Decreased fuel economy

Potential Causes

Typically, the causes for this code to set are:

Short to power in the PFS sensor signal circuit – possible
Open in the ground circuit to the PFS sensor – likely
Failed PFS sensor – possible
Failed PCM – unlikely

Diagnostic and Repair Procedures

---

A good starting point is always to search for a Technical Service Bulletin (TSB) for your specific vehicle. The vehicle manufacturer may have a PCM flash/reprogramming to address this issue, and it is worth checking before discovering you’ve taken a long/wrong path.

Next, locate the purge flow sensor on your specific vehicle. This sensor is typically mounted in the evaporative fuel system, also known as the charcoal canister, near the fuel tank or perhaps even at the top of the fuel tank module/fuel pump. Once located, visually inspect the connector and wiring. Look for scratches, rubbing, bare wires, burns, or melted plastic. Separate the connector and carefully inspect the terminals (the metal parts) inside the connector. See if they appear burnt or have a greenish tint indicating corrosion. Use electrical contact cleaner and a plastic-bristled brush if terminal cleaning is needed. 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 P0468 code returns. If not, the connections were likely your problem.

If the P0468 code returns, we will need to test the PFS sensor and its associated circuits. With the key off, disconnect the electrical connector from the PFS sensor. Connect a black wire from the digital voltmeter to the ground terminal at the PFS sensor wiring harness connector. Connect the red wire from the digital voltmeter to the power supply terminal at the PFS 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. If not, repair the power or ground wire or replace the PCM.

If the previous test passes, we will need to test the signal wire. With the connector still disconnected, move the red voltmeter wire from the power wire terminal to the signal wire terminal. The voltmeter should now read 5 volts. If not, repair the signal wire or replace the PCM.

If all previous tests pass and you continue to get a P0468, this would most likely indicate a faulty PFS sensor, although a faulty PCM cannot be ruled out until the PFS sensor has been replaced. If in doubt, seek assistance from a qualified automotive diagnostician. PCMs need to be programmed or calibrated to the vehicle to be installed correctly.