P093C code meaning
Hydraulic Accumulator Solenoid Circuit High
Powertrain system Generic code P09xx codes Check engine light
What P093C means
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.
P093C at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P093C
- Warning light on (after repeated detection)
- Engine stop-start no longer active
- Jolt when pulling away after a restart
Common causes of P093C
- Most likelySolenoid control wire shorted to battery voltage
- PossibleDamaged internal transmission harness or lead frame
- Less likelyOutput driver in the control module failed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hydraulic accumulator solenoidWiring harnessTCM
What each part of P093C means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 9 | Area: transmission. |
| 3C | The exact fault in that area. |
What to do next
- Note P093C and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P093C
What does P093C mean?
P093C means "Hydraulic Accumulator Solenoid Circuit High". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P093C?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P093C fail an emissions test?
Yes, it can. P093C is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P093C to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P093C clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.