Fault Isolation Procedure (4-Cyl)

Checking the sensor's grounding:
- Unplug the connector: Intake air temperature sensor 407.
- Connect Test Lamp (86 1 857) to B+ and pin 2 of the female connector.
- Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.
If the test lamp illuminates, go to step 3, otherwise go to next step.
Rectifying the lead: The lead from crimp connection J17 to pin 2 of the female connector is faulty. Rectify the fault and go to step 7.
Checking the control module's sensor input:
- Turn the ignition switch to the ON position.
- Contact ECM.
- Read value: Intake Air Temperature.
If the reading shows -40°C, go to step 5, otherwise go to next step.
Rectifying the lead: The lead from pin 1 of the female connector to pin 15 of the control module is faulty. Rectify the fault and go to step 7.
Checking the control module's sensor input (continued):
- Connect a jumper lead between pins 1 and 2 of the female connector.
- Read value: Intake Air Temperature.
If the reading shows 139°C, go to next step, otherwise go to step 4.
Changing components: Change the intake air temperature sensor. When finished go to next step.
Final check:
- Clear the DTCs in all systems.
- Carry out a drive cycle: Drive the car at varying engine loads and engine RPM for 5 minutes.
- Evaluate the drive cycle: Check that the DTC has not recurred.
If the trouble code has recurred, the ECM is faulty. If the code is no longer present, the fault has been rectified.