Diagnosis & Repair Procedure
- 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. Backprobing at ECM, measure voltage between ground and ECM harness connector E92 terminal No. 32 (Yellow wire). See Figure . With A/C off, and engine coolant temperature less than 221°F (105°C), reading should be 10-14 volts. With A/C on, and engine coolant temperature 221°F (105°C) or more, reading should be 0-2 volts. If voltages are as specified, problem is probably intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article. If intermittent problem is not found, substitute a known good ECM, and repeat DTC CONFIRMATION TEST . If voltages are not as specified, go to next step.
- Turn ignition off. Remove A/C cooling fan relay from engine compartment fuse/relay block at left side of engine compartment. See Figure . Check cooling fan relay socket cavities and relay terminals for clean tight connections. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If no problem is found, go to next step.
- Working with relay, measure resistance between A/C condenser fan relay terminals No. 3 and 4. If resistance is 70-110 ohms, go to next step. If resistance is not 70-110 ohms, replace A/C cooling fan relay. After repair, repeat DTC CONFIRMATION TEST .
- Check for open or short in Light Green wire between A/C cooling fan relay and ignition switch. See WIRING DIAGRAMS article. Also, check for open or short in Yellow wire between A/C cooling fan relay and ECM harness connector E92 terminal No. 32. See Figure . If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If no problem with wiring is found, go to next step.
- Substitute a known good ECM, and retest system. After repair, repeat DTC CONFIRMATION TEST . If DTC does not reset, testing is complete.