KlaroFault codeP0066
MODERATEAir Assisted Injector Control Circuit or Circuit Low
What this code means
Air Assisted Injector Control Circuit or Circuit Low.
P0066 is a generic code: it means the same thing on every make. P0066 belongs to family P00xx — Fuel and air metering, auxiliary emission controls. Its page explains how to read a code and groups all its codes by part.
Type of fault
The control unit reads a voltage on this circuit below its expected range. Usual causes: a wire shorted to ground or broken, a corroded or loose connector, or the component itself. Check the wiring and connector before replacing the part — that is where many of these faults turn out to be.
Air-assisted injector system
On a few engines, a little air is blown into the injectors to atomise fuel more finely, especially at idle and on cold starts. A valve controlled by the control unit lets that air through.
What you notice
Rough idle or hesitation on cold starts are the most common signs; often nothing at all once warm.
How to check it
Look for a disconnected or split air hose between the intake and the injectors, then check the control valve's connector and its resistance with a multimeter.
What to do
Have it checked this week. The car remains usable, but the fault will not clear itself and will fail the roadworthiness test.
Clearing a code switches the light off but repairs nothing: if the fault remains, the code comes back. Clearing a fault code yourself →
How to read this code
- PPowertrain
- 0standardised code
- 0Fuel and air metering, auxiliary emission controls
- 66P0066
