What it means
The auxiliary transmission fluid pump control module feedback signal is higher than expected.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The auxiliary transmission pump control module sends a feedback signal that the vehicle's control system uses to monitor pump operation. This code sets when that signal rises above the expected level. A short to voltage, a poor connection, or a faulty module can make the feedback read high.
Common causes
Most likely first.
- Short to voltage in feedback wiring
- Poor connector connection
- Faulty pump control module
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Save freeze-frame data and check live feedback to confirm it is high and note whether the pump was commanded on at the time.
- Inspect the feedback wiring and pump module connector for chafing against power wires, corrosion, loose pins, or heat damage.
- Using the manufacturer's wiring information, test the feedback circuit for a short to voltage and check for unwanted connections to adjacent circuits.
- If supported by the scan tool, command pump operation and observe whether the feedback remains high or responds to the command.
- Verify module power and ground connections according to the manufacturer's procedure.
- If wiring and connections pass, diagnose the pump module's feedback output for an internal fault.
Common fixes
- Repair a short to voltage or damaged insulation in the feedback wiring.
- Repair loose or corroded terminals at the pump module connector.
- Correct a faulty module power or ground connection if found.
- Replace the pump control module if it continues to output high feedback with a sound circuit.
Can I keep driving?
Avoid driving if the transmission slips, shifts unpredictably, or enters limp mode, because pump operation may not be verified correctly. If shifting is normal, minimize driving and have the high feedback signal checked promptly.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.