Switch Test E.7.2 - ISC Throttle Switch

After .7.0 is displayed on FDC, PCM switch test can be initiated by depressing brake pedal. When brake pedal has been depressed, FDC will display E.7.0. At this time the HI and LO buttons on ECC panel can be used to select specific switch test.

When a specific test has been selected and that switch activated, display will alternately display code for that test and E.0.0 to confirm that switch is working.

This test detects opening and closing of ISC nose switch at PCM terminal A7.

1. Throttle body must be removed to disconnect ISC jumper from ISC. Using DVOM, check jumpers for open or shorted circuit and ISC switch for continuity.

Fig 1: Switch Test E.7.2 Schematic - ISC Throttle Switch

Courtesy of GENERAL MOTORS CORP.

Fig 2: Switch Test E.7.2 Flow Chart - ISC Throttle Switch

Courtesy of GENERAL MOTORS CORP.