What does it mean?
This generic powertrain/engine diagnostic code generally applies to all vehicles equipped with OBD-II, including but not limited to Jeep, Dodge, Mazda, Nissan, Honda, GM, etc.
The Transmission Fluid Pressure Sensor/Switch (TFPS) is typically found attached to the side of the valve body inside the transmission, although sometimes it may 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 “G” 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 “G” circuit is for your particular vehicle.
P083B is generally an electrical circuit problem (TFPS sensor circuit), although, as mentioned earlier, this code can also be set due to mechanical issues (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 by manufacturer, TFPS sensor type, and wire colors.
Related “G” Transmission Fluid Pressure Sensor circuit codes:
- P083A Transmission Fluid Pressure Sensor/Switch, “G” circuit
- P083C Transmission Fluid Pressure “G” Sensor/Switch Low
- P083D Transmission Fluid Pressure “G” Sensor/Switch High
- P083E Transmission Fluid Pressure “G” Sensor/Switch, intermittent circuit
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 P083B 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 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 during diagnosis.
A good example of this would be if there are known power-related codes with P083B, 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 P083B.
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 memory and see if the P083B 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 P083B 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 the manufacturer’s specifications