What it means
The control system detects that auxiliary transmission fluid pump A is drawing more current than expected.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Auxiliary transmission pump A circulates fluid when the transmission needs hydraulic pressure that the main pump may not provide. The control module monitors the electrical load while it commands pump A to run. This code sets when the motor draws more current than the module expects, which can indicate a binding pump or an electrical fault.
Common causes
Most likely first.
- Pump motor or pump mechanically binding
- Shorted pump motor winding
- Pump wiring or connector fault
- Faulty pump driver
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 transmission live data for when pump A was commanded on and whether current was reported high.
- With the vehicle safely parked and the system powered down as specified by the manufacturer, inspect pump A, its connector, and wiring for damage, corrosion, fluid intrusion, or pinched sections.
- Check transmission fluid level and condition using the manufacturer's procedure, since a fluid or mechanical problem can increase pump load.
- If supported by the scan tool, command pump A and compare its reported current and operation with the manufacturer's specification.
- Test pump A wiring for shorts and measure motor resistance or current draw using the manufacturer's procedure to distinguish a binding motor from a wiring fault.
- If pump and wiring checks pass, diagnose the pump driver for an output fault before replacing it.
Common fixes
- Repair a loose, corroded, or damaged pump A connector or wiring.
- Correct transmission fluid level or condition if it is outside the manufacturer's requirements.
- Replace pump A if it binds or its motor winding draws excessive current.
- Repair or replace the pump driver if testing confirms it is faulty.
Can I keep driving?
Avoid driving if shifts are slipping, harsh, delayed, or the vehicle enters limp mode; loss of hydraulic pressure can damage the transmission or leave you without drive. If shifting remains normal, limit driving 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.