P27E4
Electric/Auxiliary Transmission Fluid Pump Control Valve Circuit Range/Performance
The control circuit for the auxiliary transmission fluid pump control valve reports a circuit range/performance condition. Pump pressure regulation cannot be commanded as expected.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
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
Common causes
Ordered by how often each turns out to be the cause.
- Coil resistance out of rangePossible
- High-resistance contact in connectorPossible
- Sensor element aged beyond calibration windowLess likely
Parts involved
- Aux Transmission Pump Control Valve
- Wiring Harness
- TCM
P27E4 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.