What it means
The auxiliary transmission fluid pump control module circuit reports a circuit/open condition.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The pump control circuit carries commands and electrical power needed to operate the auxiliary transmission fluid pump. This code sets when the circuit is open, so the control module may be unable to operate the pump as requested.
Common causes
Most likely first.
- Open or damaged wiring in the pump control circuit
- 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
- Capture freeze-frame data and review live transmission data for pump commands and any related power or communication faults.
- Inspect the pump control module connector and control wiring for disconnection, broken wires, corrosion, or loose terminals.
- Using the vehicle wiring information, check circuit continuity from the module through the pump control path.
- Check the control circuit's power and ground supplies and inspect any relevant fuse or connection identified by the wiring diagram.
- If the wiring and supplies are intact, test the pump control module output using the manufacturer's procedure.
Common fixes
- Reconnect a disconnected control circuit connector.
- Repair an open or damaged pump control wire.
- Clean and secure corroded or loose terminals.
- Replace a failed fuse after checking for the underlying cause.
- Replace the pump control module if its circuit output has failed.
Can I keep driving?
If the transmission shifts harshly, late, or unpredictably, or is locked in one gear, avoid driving because pump control may be unavailable and further transmission problems can develop. If it shifts normally, limit use 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.