Code 21, Throttle Switch Circuit (M/T Only) Both Idle Switch Wide Open Throttle Switch Indicated On: Notes

On vehicles equipped with a manual transaxle, the ECM supplies 4-5 volts to throttle switch on throttle body. When throttle is closed, the ECM sees a low signal voltage on Light Green/Yellow wire. When throttle is opened slightly, ECM sees high signal voltage on Light Green/Yellow wire. When throttle is wide open, ECM sees low signal voltage on Light Green/White wire. Code 21 sets if ECM sees signal voltage at ECM terminals A3 (Light Green/Yellow) and A15 (Light Green/White) greater than 4-9 volts at the same time for more than .3 second.

1. A poor connection or a ground circuit will indicate a low signal.
2. This checks circuit for a short to ground or misadjusted throttle switch.
3. See ADJUSTMENTS article.