P0C25: Electric/Auxiliary Transmission Fluid Pump Control Module Circuit High

P0C25 reports that the circuit from the controlling module to the auxiliary pump control module sits high, for instance a command wire shorted to battery voltage or an output that cannot pull the line down. No manufacturer documents this exact code publicly. Ford's 2016 F-150 2.7L bulletin shows the type of signal involved: a PCM duty-cycle command that can be swept from 20 to 90 percent to prove pump operation. A line stuck high can be read as a constant full command or rejected as invalid, so the pump may run continuously or be shut off. GM's ELR pump controller also uses a separate wake-up line as enable. CARB requires circuit monitoring of such outputs. P0C23 is the open circuit, P0C24 the low side, P0C2E the high fault on the feedback line.

Symptoms

• MIL or transmission warning
• Pump runs continuously or start-stop is disabled

Most likely causes

• Command wire shorted to battery or another supply voltage
• Output stage in the PCM/TCM stuck high
• Input stage of the pump control module faulty

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the battery and grounds
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Clear the code and see if it returns
4. If it is a reference voltage code, disconnect sensors one at a time and see if the voltage recovers
5. Check whether a software update is available
6. Do not replace the control module without a full diagnosis

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P0C25 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• C: Subsystem depends on the code range
• 25: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0C25?

It depends on the symptoms. If the car is running normally you can go to a repair shop; if it goes into limp mode, drive as little as possible.

What causes code P0C25?

The most common causes are: command wire shorted to battery or another supply voltage; output stage in the PCM/TCM stuck high; input stage of the pump control module faulty.

Related codes

• P0C23Electric/Auxiliary Transmission Fluid Pump Control Module Circuit/Open
• P0C24Electric/Auxiliary Transmission Fluid Pump Control Module Circuit Low
• P0C2EElectric/Auxiliary Transmission Fluid Pump Control Module Feedback Signal High
• P2796Electric/Auxiliary Transmission Fluid Pump A Control Circuit/Open

Sources

• law.cornell.edu: 13 CCR 1968.2
• static.nhtsa.gov: MC 10108996 9999
• gsi.ext.gm.com: 16OBDG01 Hybrid Diagnostics

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.