Note On Intermittents

Manipulate circuits No. 452 and 472 wiring, IAT sensor connector, and PCM connector while observing PCM Data PD05. If failure is induced, data value will jump from normal value to open circuit reading of -35°C to -40°C. Disconnect and reconnect both IAT sensor and PCM connectors to ensure that they are latched. If wiring and connectors are okay, substitute a known good IAT sensor and retest.

Fig 1: Code P038 Schematic, Open IAT Sensor

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code P038 Diagnostic Flow Chart, Open IAT Sensor

Courtesy of GENERAL MOTORS CORP.