P074

DTC PO74:

IAT, MAP And TPS Circuits:

CIRCUIT DESCRIPTION
This diagnostic test monitors Intake Air Temperature (IAT) sensor voltage. If the Powertrain Control Module (PCM) detects a large change in sensor output voltage in a 0.25 second period of time, Code P074 will set.

TEST CONDITION
Two seconds have passed since ignition switch has been turned to the RUN position.

FAILURE CONDITION
IAT sensor voltage has changed 0.3 volt (which corresponds to an 11°C temperature change) in 250 milliseconds.

ACTION TAKEN
None.

NOTES ON FAULT TREE
1. Checking Code P074 snapshot value to determine if an intermittent high resistance or an intermittent low resistance caused the code to set. An intermittent high resistance can be caused by an open in CKT 452 or CKT 472. An intermittent low resistance can be caused by a short to ground on CKT 472.