What it means
The hydraulic accumulator solenoid reports a circuit low condition. Pressure storage charging cannot be commanded reliably.
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 controls pressure charging through an electrical circuit commanded by the TCM. P093B sets when the circuit voltage is lower than expected, which can occur with a short to ground, a shorted coil, or excessive resistance at a connection.
Common causes
Most likely first.
- Wire shorted to ground
- Internal short in coil
- Connector pins corroded - high contact resistance
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
- Save freeze-frame data and check live transmission data for accumulator solenoid commands and related circuit codes.
- Inspect the solenoid connector and harness for chafing against ground, corrosion, loose terminals, or fluid contamination.
- Check the control circuit for a short to ground and measure its continuity and resistance using the manufacturer's wiring information.
- Test the solenoid coil and connector contact quality to distinguish an internal short from wiring or terminal resistance.
- Repair the confirmed short or high-resistance connection, then verify that the solenoid circuit responds to commands.
Common fixes
- Clean and secure corroded or loose solenoid connector terminals.
- Repair control wiring shorted to ground or damaged against the transmission case.
- Replace the accumulator solenoid if its coil is internally shorted.
- Clear the code and confirm solenoid operation after repair.
Can I keep driving?
Avoid driving if the transmission slips, shudders, shifts harshly, or enters limp mode; the accumulator may not charge reliably and further driving can damage the transmission. Have the circuit repaired before normal use.
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.