P1661 GMC – MIL Control Circuit Conditions

P1661 GMC Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

P1661 GMC Possible Causes

Faulty Malfunction Indicator Lamp (MIL),Malfunction Indicator Lamp (MIL) harness is open or shorted,Malfunction Indicator Lamp (MIL) circuit poor electrical connection

P1661 GMC Description

With the engine speed over 600 rpm, the Powertrain Control Module (PCM) detects that the Actual and Commanded state of the MIL Control circuit did not match, condition met for over 5 seconds.