Powertrain
generic / SAE
P28EE
Electric/Auxiliary Transmission Fluid Pump B Underspeed
The auxiliary transmission fluid pump B falls below the calibrated minimum speed for the commanded duty. Mechanical resistance high or supply voltage low.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number8 / EE
Possible causes
- Pump mechanically binding high
- Supply voltage low under load 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
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 400–1800 €
- Estimated time: 2–7 h
- Component: aux transmission pump b
- Component: transmission fluid
- MIL / check engine light
- limp mode possible
Sources
References
sae:J2012