P093CHydraulic Accumulator Solenoid Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- The control circuit of the hydraulic accumulator solenoid reads high, typically a control wire shorted to battery voltage so the driver cannot switch the valve as commanded. No manufacturer documents P093C publicly. GM covers the same fault on its surge accumulator solenoid with P171C: failed short to voltage when the circuit impedance criterion of 0.5 Ohm is met in 6 of 8 samples, Type B with MIL after two trips. GM's patent on an accumulator with solenoid valve shows how the valve holds or releases the stored fluid. P093A is the open circuit, P093B the low fault and P093D the performance fault. Stop-start is usually disabled; a valve that never closes cannot keep the accumulator charged during an auto-stop.
- What you may notice
- Warning light on (after repeated detection)
- Engine stop-start no longer active
- Jolt when pulling away after a restart
- Likely causes
- LikelySolenoid control wire shorted to battery voltage
- PossibleDamaged internal transmission harness or lead frame
- RareOutput driver in the control module failed
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €150 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.