P28ED

Q: Can I keep driving with this code?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.

Electric/Auxiliary Transmission Fluid Pump B Overspeed

High severity

The auxiliary transmission fluid pump B exceeds the calibrated maximum speed for the commanded duty. Mechanical load on the pump unexpectedly low.

Common causes

Pump impeller damage - load lost
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $440-1980
Aerated fluid - reduced load
A plausible cause — test and verify before replacing parts.
medium
Typical part cost: $440-1980
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First things to check

1Confirm the code with a scan tool and check for additional related codes.
2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.

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Related codes

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Frequently asked questions

What does P28ED mean?

P28ED means "Electric/Auxiliary Transmission Fluid Pump B Overspeed". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.

What are the most common causes of P28ED?

pump impeller damage - load lost; aerated fluid - reduced load — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.

Can I keep driving with this code?

This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly. Use the Wrenchify app for a full diagnosis specific to your vehicle.

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