What it means
The auxiliary transmission fluid pump control module detects a high signal from its internal temperature sensor circuit.
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 monitors its own temperature through an internal sensor circuit. This code sets when that circuit signal is higher than expected, which can result from an open wire, a short to voltage, a failed sensor, or a module fault.
Common causes
Most likely first.
- Open circuit in the sensor wiring
- Short to voltage in the sensor circuit
- Faulty internal temperature sensor
- 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 review transmission live data for pump status and any internal temperature reading associated with the fault.
- Inspect the module connector and sensor wiring for an unplugged connection, broken conductor, corrosion, or pin damage that could leave the signal circuit open.
- Using the vehicle wiring information, check the sensor signal circuit for a short to voltage and verify continuity through the wiring.
- Test the internal temperature sensor according to the manufacturer's diagnostic procedure.
- If the wiring and sensor test correctly, check module power and ground before condemning the pump control module.
Common fixes
- Reconnect or repair an open sensor wire at the pump control module.
- Repair sensor wiring shorted to voltage.
- Clean and secure damaged or corroded connector terminals.
- Replace the failed internal temperature sensor if separately serviceable.
- Replace the pump control module if its sensor input has failed.
Can I keep driving?
Do not continue driving if shifting becomes harsh, delayed, or erratic, or if the transmission enters limp mode; these conditions can lead to further transmission damage. If the vehicle shifts normally, keep trips short and arrange prompt diagnosis.
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.