Note On Intermittents

Manipulate circuits No. 472 and 476 wiring, IAT connector and PCM connector while observing PCM parameter PD05. If failure is induced, IAT will jump from its normal value to open signal circuit reading of -35°C to -40°C. If wiring and connectors are okay, substitute a known good sensor, and retest.

Fig 1: PCM Code P038 Schematic - Open IAT Sensor Signal

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code P038 Flow Chart - Open IAT Sensor Signal

Courtesy of GENERAL MOTORS CORP.