Diagnostic Aids
- Operating the throttle valve with the Throttle Position control function of the scan tool may cause additional DTCs to set. DO NOT attempt to diagnose DTCs set during this function.
- The scan tool has the ability to operate the throttle actuator control system using Special Functions. This function operates the throttle through the entire range in order to determine if the throttle body and system operate correctly.
- Inspect for a condition in which the throttle valve may have been held open.
- Inspect for conditions in which ice may have formed in the throttle bore.
- The throttle valve is spring loaded to a slightly open position. The throttle valve should be open approximately 30 percent. This is referred to as the rest position. The throttle valve should not be completely closed, nor should it be open any greater than the specified amount. The throttle valve should move open and to the closed position without binding under the normal spring pressure. The throttle should NOT be free to move open or closed WITHOUT spring pressure.