What it means
The control circuit of the hydraulic accumulator solenoid is open. Pressure storage charging cannot be commanded.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The hydraulic accumulator solenoid is an electrically operated valve used to control pressure charging in the transmission's accumulator. P093A sets when the solenoid control circuit is open, so the TCM cannot complete the commanded circuit to charge pressure storage.
Common causes
Most likely first.
- Open in control wire
- Open solenoid coil
- Pin pushed back out of connector body
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
How to diagnose it
- Record freeze-frame data and check for other transmission codes that may help identify when accumulator pressure charging stopped responding.
- Inspect the accumulator solenoid connector and harness for a disconnected plug, pushed-back pin, corrosion, or broken wire.
- Check continuity through the solenoid control circuit and coil using the manufacturer's wiring information and test procedure.
- If wiring continuity is intact, test the solenoid coil and its control circuit to locate the open.
- Repair the open circuit or replace the confirmed failed solenoid, then verify that the code does not return.
Common fixes
- Reconnect the solenoid plug or secure a pushed-back terminal.
- Repair a broken or open control wire to the accumulator solenoid.
- Replace the hydraulic accumulator solenoid if its coil is open.
- Clear the code and verify accumulator solenoid operation after the repair.
Can I keep driving?
Avoid driving if shifts are harsh, delayed, slipping, or the transmission is in limp mode; accumulator pressure charging may not work correctly and continued use can worsen transmission damage. Arrange repair before relying on the vehicle for normal trips.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.