Auxiliary Transmission Fluid Pump Temp Sensor Circuit Low
The P0C1E code indicates that the internal temperature sensor circuit of the auxiliary transmission fluid pump control module is reading lower than expected. This sensor monitors the temperature of the pump's internal electronics. A low circuit condition typically means the signal voltage is below the normal range, which can be caused by a short to ground, a faulty sensor, or a malfunctioning control module. This issue can lead to improper pump operation, potentially affecting transmission cooling and lubrication, especially in hybrid or electric vehicles that rely on the auxiliary pump when the engine is off.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Transmission shifting issues or harsh engagement
- Reduced fuel economy
- Transmission overheating warning
2. Most Common Causes
- Shorted or damaged wiring in the temperature sensor circuit
- Faulty internal temperature sensor within the auxiliary pump control module
- Corroded or loose connector at the pump module
- Defective auxiliary transmission fluid pump control module
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data. Verify P0C1E is present.
Step 2: Visually inspect the auxiliary pump connector and wiring for damage, corrosion, or loose pins.
Step 3: Measure the temperature sensor signal voltage at the pump connector with a multimeter. Compare to manufacturer specifications (typically 0.5-4.5V).
Step 4: If voltage is low (near 0V), check for a short to ground in the signal wire. If wiring is okay, replace the auxiliary pump control module.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The auxiliary pump may not operate correctly, leading to transmission overheating or damage, especially in stop-and-go traffic or when the engine is off.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, depending on whether it's a wiring fix or module replacement. Parts alone can be $100-$300.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.