DTC 44

Code 44 Chart:

Idle Switch Circuit Wiring Diagram:

CIRCUIT DESCRIPTION:

Code 44 will set if ECM senses an open switch or circuit at idle conditions. The idle switch is used to signal the ECM when the throttle is in the closed or idle position. When properly adjusted, a closed throttle will pull the ECM circuit low (to ground) through the TPS idle switch. The idle switch, if measured separately, will show little or no resistance when closed. When the throttle is opened, the circuit will go high at the ECM and the switch, if measured separately, will show open or infinite resistance.

TEST DESCRIPTION: The numbers below refer to circled numbers on the diagnostic chart.

1. Applying vacuum to the throttle opener will assure that the throttle is in an idle position. Resistance should be 500 ohms or less at idle and infinite (open circuit) at wide open throttle. An improperly adjusted TPS could keep the idle switch open at closed throttle.

2. Since the TPS checks OK in step 1, this step checks for a fault being an open circuit or faulty ECM.