Error code

OBD2 P0066

OBD2P0066
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

Air Assisted Injector Control Circuit or Circuit Low.

Severity

moderateCan drive, but rough idle or stalling may occur.

Summary

P0066 indicates an issue with the air-assisted injector control circuit or low circuit voltage in the engine's fuel injection system, which helps improve fuel vaporization during cold start conditions.

Symptoms

  • Malfunction indicator light (MIL) illumination
  • Rough idle or stalling

Common Causes

  • Faulty air-assist valve
  • Vacuum leaks in the system
  • Poor electrical connections or corrosion in connectors

Diagnosis

  1. Check for technical service bulletins (TSBs) and recalls.
  2. Inspect the air-assist valve connections and functionality.
  3. Verify that rubber hoses and metal tubes are not damaged.
  4. Test AFR sensors to ensure they are functioning correctly.

Fixes

  • Replace faulty air-assist valve or repair vacuum leaks

FAQ

What should I do if the MIL is on?

Check for TSBs and recalls, inspect electrical connections, and verify that rubber hoses and metal tubes are not damaged.

Can this issue cause engine stalling?

Yes, rough idle or stalling may occur due to problems with the air-assisted fuel injection system.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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