Air Assisted Injector Control Circuit Low
The P0066 code indicates a problem with the air assisted injector control circuit, specifically that the circuit voltage is lower than expected. This system uses a solenoid to control air flow into the intake manifold to aid fuel atomization. A low circuit condition can be caused by a faulty solenoid, wiring issues, or a problem with the engine control module (ECM).
1. Most Common Causes
- Faulty air assisted injector solenoid
- Open or shorted wiring in the control circuit
- Poor electrical connection at the solenoid or ECM
- Failed ECM
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Rough idle or hesitation during acceleration
- Poor fuel economy
- Possible hard starting
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm the code and check for related codes.
Step 2: Visually inspect the air assisted injector solenoid and wiring for damage or corrosion.
Step 3: Test the solenoid resistance with a multimeter; compare to manufacturer specs.
Step 4: Check for voltage and ground at the solenoid connector with the engine running.
Step 5: If wiring and solenoid are good, test the ECM output or replace the ECM.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause poor engine performance and increased emissions. You may experience stalling or hesitation.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on the cause. A solenoid replacement is usually under $100, while wiring repairs may be less.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.