Diagnosis & Repair
- Connect scan tester to DLC3 connector. See Figure. Turn ignition on. Turn on scan tester. Monitor IAT sensor temperature. If temperature displayed is same as outside temperature, inspect component and ECM connections. Problem is intermittent.
- If temperature displayed is 284°F (140°C) or more, go to step 5). If temperature displayed is -40°F (-40°C), turn ignition off. Disconnect MAF sensor connector. Using jumper wire, connect MAF wiring harness connector terminals No. 3 and 4. See Figure. Turn ignition on. Monitor IAT sensor temperature on scan tester.
- If temperature displayed is 284°F (140°C) or more, replace MAF sensor and retest. If temperature displayed is less than 284°F (140°C), turn ignition off. Remove jumper wire. Access ECM under driver's seat. Connect jumper wire between terminals No. 3 (Blue/White wire) and No. 9 (Brown/Black wire) at ECM E6 connector. See Figure.
- If temperature displayed on scan tester is 284°F (140°C) or more, inspect and repair circuits between MAF wiring harness connector and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. If temperature displayed on scan tester is less than 284°F (140°C), replace ECM and retest.
- Turn ignition off. Disconnect MAF sensor connector. Turn ignition on. If temperature displayed on scan tester is -40°F (-40°C), replace MAF sensor and retest. If temperature displayed is not -40°F (-40°C), turn ignition off.
- Access ECM under driver's seat. Disconnect ECM E6 connector. See Figure. Turn ignition on. If temperature displayed is -40°F (-40°C), inspect and repair circuits between MAF sensor and ECM for short. See appropriate wiring diagram in WIRING DIAGRAMS article. If temperature displayed by scan tester is not -40°F (-40°C), replace ECM and retest.