Note On Intermittents

Manipulate circuit No. 472, IAT sensor connector and PCM connector while observing PCM data PD05. If failure is induced, manifold air temperature will jump from its normal value to a shorted reading of 148-151°C. Check IAT and PCM connectors and ensure that they are properly latched. If okay, substitute a known good IAT sensor and retest.

Fig 1: Code P037 Schematic (DeVille)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code P037 Flow Chart (DeVille)

Courtesy of GENERAL MOTORS CORP.