Open or damaged wiring in the hydraulic accumulator solenoid circuit, such as a broken wire or corroded connector; Failed hydraulic accumulator solenoid (open coil or internal short); Poor electrical connection at the solenoid or PCM, including loose pins or water intrusion; Blown fuse or relay supplying power to the solenoid circuit; Faulty PCM driver for the solenoid circuit (rare)

DTC codes / P09xx · Transmission / P093A

P093AHydraulic Accumulator Solenoid Circuit/Open

Q: What does code P093A mean?

Hydraulic Accumulator Solenoid Circuit/Open. P093A indicates that the powertrain control module (PCM) has detected an open circuit or excessive resistance in the hydraulic accumulator solenoid circuit. This solenoid is used in certain hydraulic systems, such as active suspension or electro-hydraulic brake systems, to control pressure stored in an accumulator. The PCM monitors the circuit and sets this code when the expected current or voltage is not present, indicating a wiring or solenoid fault.

P093A indicates that the powertrain control module (PCM) has detected an open circuit or excessive resistance in the hydraulic accumulator solenoid circuit. This solenoid is used in certain hydraulic systems, such as active suspension or electro-hydraulic brake systems, to control pressure stored in an accumulator. The PCM monitors the circuit and sets this code when the expected current or voltage is not present, indicating a wiring or solenoid fault.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

Symptoms you may notice

Illumination of the check engine light or service vehicle soon message
Often no symptoms besides the warning light
Reduced or disabled operation of the affected hydraulic system, such as suspension or brake assist
A noticeable change in ride quality or braking feel if the system is safety-related
In some cases, a warning message on the driver information center indicating a system fault

Common causes, most likely first

Open or damaged wiring in the hydraulic accumulator solenoid circuit, such as a broken wire or corroded connector
Failed hydraulic accumulator solenoid (open coil or internal short)
Poor electrical connection at the solenoid or PCM, including loose pins or water intrusion
Blown fuse or relay supplying power to the solenoid circuit
Faulty PCM driver for the solenoid circuit (rare)

How to diagnose and fix it

Verify the code with a scan tool and check for any related codes in other modules
Inspect the wiring harness and connectors at the hydraulic accumulator solenoid for damage, corrosion, or loose pins
Measure the resistance of the solenoid with a multimeter and compare to the manufacturer's specification
Check for power and ground at the solenoid connector with the ignition on and the circuit commanded on
Test the circuit for continuity and short to ground or power between the solenoid and the PCM
If the circuit tests good, suspect the PCM and perform further diagnostics before replacement
Repair or replace the faulty wiring, connector, or solenoid as needed, then clear codes and verify the repair

Don't overlook the simple wiring fault

A common cause of P093A is a chafed wire in the harness near the accumulator solenoid, often due to vibration or road debris, which can be missed if only the solenoid is tested.
The code can be set by a weak battery or charging system issue that causes low voltage during solenoid activation, so always check battery condition and connections first.
Some vehicles use the hydraulic accumulator solenoid for multiple functions, so a failure may also affect other systems like stability control or brake assist, leading to additional codes.
A solenoid that tests good with a multimeter can still fail under load or when hot, so a thorough diagnosis may require a load test or oscilloscope waveform analysis.
Replacing the solenoid without addressing a corroded connector or damaged wire will lead to a repeat failure, so always inspect the entire circuit.

Can I keep driving with P093A?

If the warning light is on but the vehicle drives normally, you can drive to a repair shop, but avoid aggressive driving or heavy loads. If the affected system is safety-related, such as brakes or suspension, and you notice reduced performance, stop driving and have the vehicle towed.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.