Note On Intermittents

Manipulate circuits No. 472 and 476 wiring, MAT connector and PCM connector while observing PCM parameter ED05. If failure is induced, MAT 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 E038, Schematic, Open MAT Sensor Circuit

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code E038, Flow Chart, Open MAT Sensor Circuit

Courtesy of GENERAL MOTORS CORP.

Fig 3: PCM Code E038