Auxiliary Transmission Fluid Pump Control Module Circuit High
The P0C25 code indicates a high voltage condition in the auxiliary transmission fluid pump control module circuit. This module manages the electric pump that circulates transmission fluid when the engine is off (e.g., in hybrid vehicles). A high circuit voltage typically points to a short to power, a faulty control module, or a wiring issue. This can lead to improper pump operation, potentially causing transmission overheating or reduced lubrication.
01. Most Common Causes
- Short to battery voltage in the control circuit
- Faulty auxiliary transmission fluid pump control module
- Damaged wiring or connector corrosion
- Failed auxiliary transmission fluid pump
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Transmission overheating or slipping
- Reduced fuel economy
- Transmission warning message on dashboard
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Inspect the auxiliary pump control module connector for corrosion, bent pins, or damage.
Step 3: Measure voltage at the control module power supply pin; should be battery voltage with ignition on.
Step 4: Check for shorts to power by disconnecting the module and testing circuit continuity to battery positive.
Step 5: If wiring is intact, replace the auxiliary transmission fluid pump control module.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with a high circuit voltage can cause the auxiliary pump to malfunction, leading to transmission damage or overheating.
How much does it cost to fix?▼
Repair costs typically range from $200 to $600, including parts (control module $100-$300) and labor ($100-$300).