P0066 Code - Air Assisted Injector Control Circuit or Circuit Low

What Does Code P0066 Mean

This code indicates that the powertrain control module (PCM) is detecting a voltage from the air assisted injector control circuit that is below specifications. When this low voltage is detected, the idle air/fuel mixture may not be within specifications and will therefore set off a Check Engine Light.

engine code P0066	P0066 fix	obd P0066	dtc P0066
obd code P0066	obd2 P0066	P0066 car code	diagnostic code P0066
car code P0066	check engine code P0066	fehlercode P0066	P0066 fiat
codigo P0066	codigo falla P0066	P0066 kody błędów	codigo de falla P0066

Common Causes

The two most common causes of this code being stored are a defective air assisted injector control solenoid or a lethargic heated upstream oxygen sensor in the affected engine bank. Other causes may include shorted, open, damaged, or corroded circuits or electrical connectors, or a faulty PCM. Techs report that this code is also exhibited in error at times and requires reprogramming of the PCM in order to correct the condition.

How do you troubleshoot P0066?

Before troubleshooting, check with your dealership service center for TSBs (technical service bulletins) or recalls, as there may be an updated part or ECM reflash available to resolve the problem. It also does good for one to note that, if the control valve has been replaced, there may be an ECM relearning procedure for the new valve.

• Control Valve Check
  • Check that the control valve is properly connected. Check the connector for corrosion or water intrusion. Repair as necessary.
  • Disconnect the air hoses from the control valve and energize the valve, either using a scan tool active test or by applying battery voltage, and see that air passes when the valve is activated. See that air does not pass when the valve is deactivated. Clean or replace as necessary.

• Air Check
  • Check that rubber hoses and tubes are in good shape, with no cracks or kinks. Check that metal tubes are not kinked. Repair as necessary.
  • Blow air into the system, at low pressure, and check for air escaping from the intake or exhaust. If air is escaping from anywhere else, suspect a faulty seal or tube. Repair as necessary. Some air may escape from around the fuel injectors, but this is not common.
• Sensor Check
  • Because the ECM monitors air-assist using the AFR sensors, if you have a sensor problem, it could set off an erroneous air-assist DTC. If you can perform a fuel trim active test, you can confirm how fast the AFR sensor reacts.

Searches related to P0066

• p0066 subaru
• air assisted injector valve
• 2002 subaru air assist injector solenoid valve