P0657
Actuator Supply Voltage A Circuit/Open
Actuator supply voltage
Generic OBD-II
High
What it means
P0657 means the actuator supply voltage 'A' circuit — the feed the ECM/PCM uses to power actuators like injectors and solenoids — is open or has lost voltage. Because those actuators depend on it, the engine can run poorly, stall, or fail to start. It's usually a wiring or connection fault or an internal module problem.
High
Can I keep driving? Often limited — this circuit powers engine actuators, so the engine can run poorly, stall, or fail to start until the open is repaired.
Common symptoms
What you'll notice
- Check-engine light on
- Engine stalls or fails to start
- Reduced engine power or acceleration
- Rough or erratic engine performance
Common causes
Most likely first
- Open or damaged wiring in the actuator supply voltage circuitLikely
- Loose or corroded connector at the ECM/PCM or actuatorsCommon
- Faulty actuator loading down or opening the supplyCommon
- Internal fault in the ECM/PCM supply driverLess often
How to diagnose & fix
Work through it in order
- Check the ECM/PCM power and ground feeds and the actuator supply circuit for an open or high resistance.
- Inspect connectors along the supply circuit for corrosion, backed-out pins, or damage.
- Test the actuators fed by this circuit to rule out one shorting or opening the supply.
- If wiring and actuators are good, the ECM/PCM supply driver may be at fault — reprogram or replace. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0657?+
Risky — because this circuit powers engine actuators, the car may stall or not restart. Drive as little as possible and get it diagnosed.
Can I just clear P0657?+
An open supply circuit will set the code again immediately. It needs the wiring, connection, or module fault repaired before clearing sticks.
Related codes
Often seen with P0657
Read & clear P0657 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX