Code 44, Idle Switch Circuit, Open Circuit Or MISADJUSTED: Notes

Throttle Position (TP) sensor has an idle switch that sends a signal to ECM. ECM applies 5 volts to idle switch. Idle switch is closed with engine at idle (low voltage signal at ECM) and open with engine off idle (high voltage signal at ECM). When ECM detects a low voltage signal, throttle valve is closed and when ECM detects a high voltage signal, throttle valve is open.

Code 44 will set when high voltage input at ECM is indicated with engine running at idle (less than 1000 RPM) for at least 10 seconds.

1. By jumpering TP sensor, ECM should detect a low voltage signal and Tech 1 should indicate ON. This determines whether problem is inwiring, ECM, or a misadjusted or faulty TP sensor.
2. Checks for open in Gray/Yellow and Blue/White wires, and a faulty ECM.