What it means
The controller detects a high electrical condition in the auxiliary transmission fluid pump control circuit.
At a glance
- Usually lights the check-engine light
How it works
The transmission controller operates the auxiliary fluid pump through a control circuit and monitors its electrical state. This code sets when the circuit reads higher than expected, which may result from a control wire shorted to battery voltage, an open pump winding, or a poor connector contact.
Common causes
Most likely first.
- Control wire shorted to B+
- Open motor winding
- Connector pins corroded - high contact resistance
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 pump command and circuit status to see under what conditions the high reading appeared.
- Inspect the auxiliary pump wiring and connector for damage, corrosion, water intrusion, pushed-back pins, or contact with a battery-voltage wire.
- Following the manufacturer's isolation procedure, check whether the control wire is shorted to battery voltage.
- Measure circuit continuity and voltage at the pump connector during a commanded test, comparing readings with the manufacturer's specification.
- If the harness and connector are sound, test the pump winding for an open circuit using the manufacturer's procedure.
Common fixes
- Clean or replace corroded or damaged connector terminals.
- Repair a control wire shorted to battery voltage.
- Repair an open in the pump control circuit.
- Replace a pump with an open motor winding.
Can I keep driving?
Limit driving if the transmission shifts harshly, slips, or hesitates; an inoperative auxiliary pump can impair fluid pressure and lead to further transmission damage. Stop if drive is lost or the transmission enters limp mode.
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.