Diagnosis & Repair
- Access ECM. ECM is located behind center console. Turn ignition on. Using DVOM, backprobe ECM harness connector. Measure voltage between terminals THA and E2. Voltage should be .5-3.4 volts for cool intake air temperature and .2-1.0 volt for hot intake air temperature.
- If voltages measured are within specification, inspect connections, problem may be intermittent. If voltages are NOT within specification, go to next step.
- Inspect IAT. See the SYSTEM/COMPONENT TESTS article. Replace as needed. If IAT is okay, inspect circuits between IAT and ECM for opens or shorts. See wiring diagram in the WIRING DIAGRAMS article. Repair as needed. If circuits are okay, replace ECM and retest.