P1666
P1666Overrun Recirculating Air Valve - Signal Implausible
Diagnostic conditions
- Vehicle is driven with a repeatedly alternating high load and subsequent release of the throttle (deceleration phase)
- No output stage faults in overrun recirculating air solenoid (P1657, P1658, P1659)
Possible cause of fault
- Overrun recirculating air valve stuck in closed position at times (due to ice)
- Overrun recirculating air valve faulty
Affected terminals
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NOTE:
- The diagnosis detects pulsations in the intake air tract from the boost pressure sensor reading. When the overrun recirculating air valve is stuck in closed position, these are produced by the exhaust turbocharger (pumping in the direction of the closed throttle valve).
- This fault can also occur in extremely cold conditions when the membranes of the overrun recirculating air valves can be frozen solid for a short time just after you start the engine.
Diagnosis/troubleshooting
