Pcm Code P037 - Shorted Intake Air Temp (IAT) Sensor Signal: Action

PCM turns on SERVICE ENGINE SOON light. PCM substitutes 104°F (40°C) for IAT when coolant temperature is greater than or equal to 104°F (40°C). PCM substitutes coolant temperature for IAT when coolant temperature is less than or equal to 104°F (40°C).

1. With a shorted IAT sensor, PCM parameter PD05 should indicate 148°C or greater. If PD05 does not indicate 148°C or greater, sensor is not shorted. See NOTE ON INTERMITTENTS.
2. Checks for sensor short or circuit No. 472 shorted to ground. If PCM parameter PDO5 stays at 142-151°C with sensor unplugged, circuit is shorted to ground.
3. IAT sensors can be damaged by a backfire in intake. If vehicle has had more than one IAT sensor replaced, check for signs of backfire and high intake manifold temperatures due to improper valve train operation.
4. Fault is most likely at PCM connector or PCM. Check for damaged PCM terminals or poor connection before replacing PCM.