Note On Intermittents

Ensure ISC plunger is depressed when throttle linkage contacts stop screw. Check ISC jumper connectors and PCM connector for loose or improperly crimped terminals.

Fig 1: PCM Code E027, Schematic, Open Throttle Switch Circuit

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code E027, Flow Chart, Open Throttle Switch Circuit

Courtesy of GENERAL MOTORS CORP.

Fig 3: PCM Code E027