Note On Intermittents

Select PCM switch test. Manipulate ISC connector, ISC wiring and PCM connector. Observe display. If throttle switch state changes momentarily, 00 will appear on display. Check for intermittent open or short in TP sensor wiring. Manipulate TP sensor connector and wiring while observing PCM data P.0.1. Watch for TP sensor value to jump to greater than 20 degrees at closed throttle.

Fig 1: PCM Code E26 Schematic - Shorted Throttle Switch Ckt.

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code E26 Flow Chart - Shorted Throttle Switch Ckt.

Courtesy of GENERAL MOTORS CORP.