P0659
Actuator Supply Voltage A Circuit High
Actuator power supply
Generic OBD-II
High
What it means
P0659 means the ECM sees the "A" actuator power-supply circuit reading higher than expected. That supply feeds output devices such as injectors, coils, or solenoids, so an over-voltage condition can disable several of them at once. Effects range from reduced power and rough running to a no-start, depending on which actuators share the circuit.
High
Can I keep driving? Risky — the ECM's actuator power supply reads high, which can knock out injectors, coils, or valves that share it. Depending on what's fed, the engine may run poorly, stall, or not start.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced power or limp mode
- Rough idle or stalling
- Multiple actuator faults, or a no-start, if the affected supply feeds critical devices
Common causes
Most likely first
- Short to voltage in the actuator supply 'A' circuit wiringLikely
- Damaged or chafed wiring feeding the actuatorsCommon
- Corroded or loose connectors on the supply circuitCommon
- Overcharging / high system voltage upstreamLess often
- Internal ECM driver fault (checked last)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check overall charging voltage first to rule out a system-wide overcharge.
- Inspect the actuator supply 'A' wiring and connectors for a short to voltage, chafing, or corrosion.
- Identify which actuators share supply 'A' and check them for a fault back-feeding the circuit.
- Measure the supply voltage at the ECM against the manufacturer's spec.
- Repair the wiring; replace and program the ECM only if its driver is confirmed faulty.
FAQ
Quick answers
Is it safe to drive with P0659?+
Use caution. If the affected supply feeds injectors or coils, the engine can run poorly, stall, or fail to start. Have it diagnosed before relying on the car.
Can I just clear P0659?+
It clears, but returns while the supply circuit reads high. Find the short or overcharge condition and repair it first.
Related codes
Often seen with P0659
Read & clear P0659 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