Transmission Fluid Pressure Sensor/Switch "C" Circuit Range/Performance
The transmission control module detected an out-of-range signal from the transmission fluid pressure sensor circuit C. This typically indicates an electrical problem in the sensor circuit rather than actual fluid pressure issues, though the PCM may alter shift timing to compensate.
What You Might Notice
- Check engine light illuminated
- Transmission shifting irregularly or delayed
- Transmission may default to limp mode or fixed gear
- Difficulty accelerating or reduced power
- Possible transmission overheating if shifts are incorrect
Most Common Causes
- 1
Open circuit in sensor wiring
A break or disconnection in the transmission fluid pressure sensor C circuit wiring or connectors, preventing signal transmission to the PCM/TCM.
- 2
Short to voltage in sensor circuit
The sensor signal wire is shorted to a positive voltage source, causing the PCM/TCM to receive an abnormally high signal reading.
- 3
Failed transmission fluid pressure sensor
The TFPS sensor has internally failed or become stuck, producing an out-of-range signal that doesn't reflect actual fluid pressure conditions.
- 4
Internal transmission mechanical problem
Severe transmission wear or internal damage may cause abnormal fluid pressure characteristics that exceed sensor range limits.
How to Diagnose It
- 1
Check Open circuit in sensor wiring — A break or disconnection in the transmission fluid pressure sensor C circuit wiring or connectors, preventing signal transmission to the PCM/TCM.
- 2
Check Short to voltage in sensor circuit — The sensor signal wire is shorted to a positive voltage source, causing the PCM/TCM to receive an abnormally high signal reading.
- 3
Check Failed transmission fluid pressure sensor — The TFPS sensor has internally failed or become stuck, producing an out-of-range signal that doesn't reflect actual fluid pressure conditions.
- 4
Check Internal transmission mechanical problem — Severe transmission wear or internal damage may cause abnormal fluid pressure characteristics that exceed sensor range limits.
How to Fix It
- 1
Inspect and repair sensor wiring
Visually inspect the transmission fluid pressure sensor C circuit for loose connectors, broken wires, corrosion, or damaged insulation. Repair or reseat connectors as needed and check for proper continuity.
- 2
Test and replace TFPS sensor
Use a multimeter to test the transmission fluid pressure sensor for proper resistance and voltage output. If readings are out of specification, replace the sensor with an OEM or quality equivalent.
- 3
Verify PCM/TCM connector integrity
Check the transmission control module or PCM connectors for corrosion, bent pins, or loose connections. Clean corroded contacts and reseat connectors firmly.
- 4
Perform transmission system inspection
If electrical tests pass but code persists, have a transmission specialist diagnose for internal mechanical failure. Low fluid level or contamination may also trigger this code and should be checked.
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