P0B09
Electric/Auxiliary Transmission Fluid Pump A Motor Supply Voltage Circuit/Open
The supply voltage circuit of auxiliary transmission fluid pump A motor reports a open condition.
- 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.
- Open in supply wireCommon
- Supply fuse blownPossible
- Pin pushed back out of connector bodyLess likely
Parts involved
- Aux Trans Pump A Motor
- Wiring Harness
- TCM
P0B09 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.