Powertrain
generic / SAE
P0935
Hydraulic Pump Relay Circuit/Open
Open circuit at the auxiliary hydraulic pump relay used to maintain transmission line pressure during start-stop or hybrid operation.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number9 / 35
Possible causes
- Relay coil open high
- Wiring break medium
- Pin pushed back out of connector body low
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
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 150–700 €
- Estimated time: 0.5–3 h
- Component: hydraulic pump relay
- Component: auxiliary hydraulic pump
- Component: wiring harness
- MIL / check engine light
Sources
References
sae:J2012