Electric/Auxiliary Transmission Fluid Pump A Performance/Stuck Off
The first auxiliary transmission fluid pump is commanded on but does not run.
Affected components
- Aux trans pump a
- Pump motor
Common causes
- High likelihood: Pump motor seized by sediment
- Medium likelihood: Cracked rotor magnet decouples drive
- Low likelihood: Carbon or debris buildup preventing free movement
Possible 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
Diagnostic notes
- The malfunction indicator lamp may illuminate
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.