OBD-II code · Powertrain (generic)
P0657 Actuator Supply Voltage A Circuit Open
The supply rail that powers a group of actuators (typically injectors, EGR, throttle motor) is open. Multiple downstream actuators stop working.
Is it safe to drive with P0657?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySupply relay open
- Less likelyPin pushed back out of connector body
- Less likelyCracked solder joint inside the module or sensor
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- Parts involved
- Actuator Supply Voltage A, Actuator Supply Relay A
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.