Diagnosis & Repair Procedure
NOTE:
If DTCs P0108, P0113, P0118, P0123 and/or P0118 are set along with this DTC, check for an open between ECM and IAT sensor connector. See WIRING DIAGRAMS
article.
NOTE:
Before beginning diagnosis and repair procedure, ensure ambient temperature is more than -40°F (-40°C).
- If engine system check has been performed, go to next step. If engine system check has not been performed, go to A4: ENGINE SYSTEM CHECK under SYSTEM TESTS.
- Turn ignition on. Using scan tool, observe IAT parameter. If parameter reads -40°F (-40°C), go to next step. If parameter does not read -40°F (-40°C), problem is probably intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
- Turn ignition off. Disconnect IAT sensor 2-pin harness connector. IAT sensor is located in intake air pipe, next to air cleaner housing. Check for poor, loose corroded or damaged terminal connections in IAT sensor harness connector. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST .
- Measure voltage between ground and IAT sensor harness connector terminal No. 1 (Green/Red wire). If reading is 4-6 volts, go to next step. If reading is not 4-6 volts, check for open or short to voltage in Green/Red wire between IAT sensor and ECM 16-pin connector C20 terminal No. 9. See Figure . If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST .
- Substitute a known good ECM, and repeat DTC CONFIRMATION TEST . If DTC resets, go to next step. If DTC does not reset, testing is complete.
- Using a fused jumper wire, jumper IAT sensor harness connector terminals. Turn ignition on. Using scan tool, observe IAT sensor parameter. If parameter reads 246°F (119°C), replace IAT sensor. After repair, repeat DTC CONFIRMATION TEST . If parameter reading is not as specified, go to next step.
- Check for open or poor connection in Green/Red wire between IAT sensor and ECM harness connector C20 terminal No. 9. See Figure . See WIRING DIAGRAMS article. If problem is found, repair as necessary. If no problem is found, substitute a known good ECM, and repeat DTC CONFIRMATION TEST . If DTC does not reset, testing is complete.