Air Assisted Injector Control Circuit Low
The P0066 code means the vehicle's onboard diagnostic system has detected: Air Assisted Injector Control Circuit Low. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $200 - $500 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Poor cold-start quality
- Rough idle when cold
- Increased exhaust emissions
Probable Causes (Ranked by Likelihood)
- Failed air-assisted injector control valve Very High
- Open circuit in control valve wiring High
- Corroded or disconnected connector Moderate
- ECM output driver failure Low
Step-by-Step Diagnostic Procedure
-
Confirm P0066 with scan tool
-
Measure voltage at air-assisted injector control valve connector
-
Check wiring for open circuits or breaks
-
Test control valve resistance
Frequently Asked Questions
What does P0066 mean?
P0066 means the ECM has detected a low voltage condition in the air-assisted injector control circuit, typically indicating an open circuit or failed control valve.
What vehicles get P0066?
P0066 is primarily found on European vehicles, particularly Volkswagen and Audi models with air-assisted fuel injection systems.
Is P0066 expensive to fix?
Repair costs range from $200 to $500, depending on whether the control valve, wiring, or connector needs to be repaired or replaced.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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