P277C
Electric/Auxiliary Transmission Fluid Pump B Motor Stalled
The second auxiliary transmission fluid pump motor is commanded on but the rotor does not turn.
- 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.
- Impeller jammed by sediment or debrisCommon
- Motor seized by bearing failurePossible
Parts involved
- Aux Trans Pump B
- Pump Motor
P277C 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.