Code 44, Idle Switch Circuit Open Or MISADJUSTED
This code will set if ECM sees an open switch or circuit at idle conditions. When properly adjusted, the TPS idle switch will pull ECM circuit low (to ground) when throttle is closed. If idle switch resistance is measured separately, it will show little or no resistance when closed. When throttle is opened, the circuit will go high at the ECM. If idle switch is measured separately, it will show open (infinite resistance).
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- Applying vacuum to throttle opener will ensure throttle is in idle position. Resistance should be 500 ohms or less at idle and infinite at wide open throttle. If TPS is misadjusted, this could keep idle switch open at closed throttle.
- TPS checked okay in step 1), this will check for an open circuit or faulty ECM.