OBD-II code · Powertrain (generic)
P0066 Air Assisted Injector Control Circuit Low
Control voltage of the air-assist injector valve is below the expected range — short to ground or low-resistance fault.
Is it safe to drive with P0066?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyWiring shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–3 h
- Emissions test
- Likely to fail
- Parts involved
- Air Assist Valve, Actuator Wiring
Related codes
- P0063HO2S Heater Control Circuit Low Bank 2 Sensor 3
- P0064HO2S Heater Control Circuit High Bank 2 Sensor 3
- P0065Air Assisted Injector Control Range/Performance
- P0067Air Assisted Injector Control Circuit High
- P0068MAP/MAF - Throttle Position Correlation
- P0069Manifold Absolute Pressure - Barometric Pressure Correlation
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.