Auxiliary Transmission Fluid Pump Control Module Internal Temperature Sensor Circuit High
The P0C1F code indicates that the internal temperature sensor circuit within the auxiliary transmission fluid pump control module is reading a voltage higher than the expected range. This sensor monitors the temperature of the control module to prevent overheating. A high voltage reading typically suggests a short to power, a faulty sensor, or an internal module failure. This can lead to improper pump operation, affecting transmission cooling and lubrication, especially in hybrid or electric vehicles with auxiliary pumps.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Transmission overheating or reduced performance
- Auxiliary pump not operating when needed
- Possible transmission slipping or harsh shifting
2. Most Common Causes
- Short to battery voltage in the temperature sensor circuit
- Faulty internal temperature sensor within the control module
- Failed auxiliary transmission fluid pump control module
- Corroded or damaged wiring/connectors
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data to confirm P0C1F.
Step 2: Visually inspect the auxiliary pump control module connector and wiring for damage, corrosion, or shorts.
Step 3: Using a multimeter, check the temperature sensor signal circuit for voltage (should be 0.5-4.5V at room temp; high voltage indicates a short to power).
Step 4: If circuit voltage is normal, test the sensor resistance per manufacturer specs; replace module if out of range.
Step 5: If sensor and wiring are okay, replace the auxiliary transmission fluid pump control module.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The auxiliary pump may fail, leading to transmission overheating and potential damage, especially in stop-and-go traffic or hybrid operation.
How much does it cost to fix?▼
Repair costs typically range from $200 to $600, depending on whether the control module needs replacement and labor rates.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.