P0066 OBD II Trouble Code Air Assisted Injector Control Circuit Or Circuit Low
How to quickly diagnose, repair, and info on symptoms and causes of a P0066 code that means there is a low circuit or malfunction with the air assisted injector control system.
Symptoms of P0066 OBD II Trouble Code
- Hard to start when engine is cold
- Poor performance when cold
- Engine misfiring
- Poor fuel mileage
Common Causes of P0066 OBD II Trouble Code
- Broken or damaged wiring harness
- Vacuum leak within injector or in hoses/clamps
- Fuse/relay defective
- Air Assisted Fuel Injector defective
- ECM issue
- Pin/connector problem. (e.g. corrosion, overheating, etc.)
Severity of P0066 OBD II Trouble Code
I would say the severity of this code is moderate to low. Reason being, it will not affect overall performance of engine at normal operating temperature. That being said, it will need to be addressed eventually as consistent cold starts with a possibly lean mixture could cause serious damage in the long run.