Diagnostic Procedures
- Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC SYSTEM CHECK . After performing OBD system check, go to next step.
- Using scan tool, check if other DTCs are present. If other DTCs are present, diagnose affected DTCs first. If no other DTCs are present, go to next step.
- Allow engine and vehicle temperature to stabilize to ambient temperature. Allowing temperature to stabilize overnight will ensure most accurate results. Turn ignition on, engine off. Using scan tool, compare ECT and IAT sensor readings. If both sensors have the same reading, see DIAGNOSTIC AIDS . If both sensors do not have the same reading, go to next step.
- Place a thermometer near IAT sensor. Compare thermometer reading to IAT sensor reading on scan tool. If IAT sensor reading is close to actual ambient temperature, go to next step. If IAT sensor reading is not close to actual ambient temperature, go to step 6.
- Replace ECT sensor.
- Replace IAT sensor.