P074

Code PO74:

Sensor Circuit:

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

TEST CONDITIONS:
Two seconds have passed since Ignition Switch has been turned to the RUN position.

FAILURE CONDITIONS:
Intake Air Temperature (IAT) sensor voltage has changed 0.3 volt (11°C) in 250 milliseconds (0.25 second).

ACTION TAKEN:
None.

NOTES ON FAULT TREE:
1. Checking Code PO74 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 476 or CKT 472. An intermittent low resistance can be caused by a short to ground on CKT 472.