P093B code meaning
Hydraulic Accumulator Solenoid Circuit Low
Powertrain system Generic code P09xx codes Check engine light
What P093B means
The control circuit of the hydraulic accumulator solenoid reads low, usually a control wire shorted to ground or a coil with very low resistance. No manufacturer documents P093B publicly. GM covers the same fault on its surge accumulator solenoid with P171B: failed short to ground when circuit impedance drops below 0.5 Ohm in 32 of 40 samples, Type B with MIL after two trips. The accumulator holds pressurised fluid so clutches stay applied during an engine auto-stop, as GM's stop-start accumulator patent explains. P093A is the open-circuit fault, P093C the high fault and P093D the performance fault. A grounded control line can leave the valve permanently energised, and stop-start is typically switched off.
P093B 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 P093B
- Warning light on (after repeated detection)
- Engine stop-start no longer active
- Harsh engagement after restart
Common causes of P093B
- Most likelySolenoid control wire shorted to ground
- PossibleSolenoid coil shorted internally
- 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 P093B 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. |
| 3B | The exact fault in that area. |
What to do next
- Note P093B 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 P093B
What does P093B mean?
P093B means "Hydraulic Accumulator Solenoid Circuit Low". The control circuit of the hydraulic accumulator solenoid reads low, usually a control wire shorted to ground or a coil with very low resistance. It is a generic code, so it means the same on every make.
Is it safe to drive with P093B?
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 P093B fail an emissions test?
Yes, it can. P093B 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 P093B to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P093B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.