Cause
Seized pump motor
A pump's motor will not turn — the shaft is jammed rather than the circuit being faulty.
It is diagnostically one of the better faults, because it is a mechanical fact rather than a measurement. The module knows the difference: current is flowing and rotation is not happening, which no wiring problem produces. That rules out the whole electrical half of the usual list before anything is measured.
What jams a pump is nearly always what is in the fluid rather than the pump itself. Wear particles, sealant from a previous repair, or debris shed by a failing component upstream reach a pump whose clearances are measured in fractions of a millimetre. Bearings seize too, but they are the second answer rather than the first — and the distinction matters, because a pump replaced into contaminated fluid seizes again. Whatever is circulating has to come out with it.
One case is not a failure at all and is worth eliminating before anything is bought. Cold, thick fluid can stall a small pump on a hard frost, and the same pump runs perfectly once warm. So a stall reported on one freezing morning, with no repeat, is often the weather — and the wrong fluid specification makes that far likelier, because a fluid too viscous for the temperature range is a stall waiting for a cold night.
Typically specialist work. Needs equipment or training most home workshops do not have.
Codes this can cause (10)
Codes where this is a likely explanation first, rather than merely a possible one.
- P023B Charge Air Cooler Coolant Pump A Control Circuit Low Likely for this code Moderate
- P0C28 Electric/Auxiliary Transmission Fluid Pump A Motor Current High Likely for this code Moderate
- P0C2A Electric/Auxiliary Transmission Fluid Pump A Motor Stalled Likely for this code High
- P0CFF Hybrid/EV Battery Pack Coolant Pump A Stuck/Stalled Likely for this code High
- P2633 Fuel Pump B Control Circuit Low Likely for this code High
- P026E Charge Air Cooler Coolant Pump A Performance Moderate
- P0B02 Electric/Auxiliary Transmission Fluid Pump Motor Phase U Current High Moderate
- P0B05 Electric/Auxiliary Transmission Fluid Pump Motor Phase V Current High Moderate
- P0B08 Electric/Auxiliary Transmission Fluid Pump Motor Phase W Current High Moderate
- P2602 Coolant Pump A Control Circuit Low High
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Others who found this
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about Seized pump motor.