P093AHydraulic Accumulator Solenoid Circuit/Open
- 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 solenoid that opens or locks a hydraulic accumulator in the gearbox is open. Such accumulators store pressurised fluid, for example to keep clutches applied during engine stop-start, as GM's patents on a stop-start accumulator and an accumulator with solenoid valve describe. No manufacturer documents P093A publicly. GM uses its own P171A for the same fault on the surge accumulator solenoid: failed if circuit impedance exceeds 200 kOhm in 32 of 40 samples, Type B with MIL after two trips. P093B and P093C are the low and high faults, P093D the performance fault. Stop-start is usually disabled, and the first restart may engage with a jolt.
- What you may notice
- Warning light on (after repeated detection)
- Engine stop-start no longer active
- Jolt or slip when driving off after an engine restart
- Likely causes
- LikelyAccumulator solenoid coil open
- PossibleConnector unplugged or wire broken between module and solenoid
- PossibleFault in the 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.