Note On Intermittents

Ensure ISC plunger is depressed when throttle linkage contacts stop screw. Check ISC jumper connector, engine-to-dash connector and PCM connector for improperly crimped or backed-out terminals.

Fig 1: PCM Code E27 Schematic - Open Throttle Switch Ckt.

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code E27 Flow Chart - Open Throttle Switch Ckt.

Courtesy of GENERAL MOTORS CORP.