DTC Troubleshooting
DTC TROUBLESHOOTING CHART
| Step |
Action |
YES |
NO |
| 1 |
Was "Engine and Emission Control System Check" performed? |
Go to Step 2. |
Go to ENGINE AND EMISSION CONTROL SYSTEM CHECK . |
| 2 |
Wire harness check
- Turn ignition switch OFF position.
- Disconnect connectors from IAT sensor and ECM.
- Check for proper terminal connection to IAT sensor and ECM connectors.
- If connections are OK, check that IAT sensor circuit is as follows.
- Wiring harness resistance of each IAT sensor signal and ground circuit is less than 3 Ω.
- Insulation resistance of IAT sensor signal circuit is infinity between IAT sensor connector and vehicle body ground.
- Insulation resistance of wire harness is infinity between IAT sensor signal terminal and each other terminal at MAF and IAT sensor connector.
- Circuit voltage of each IAT sensor signal and ground circuit is 0 - 1 V with ignition switch turned ON.
Are they in good condition? |
Go to Step 3. |
Repair or replace defective wire harness. |
| 3 |
IAT sensor reference voltage check
- Connect connectors to ECM.
- Turn ignition switch to ON position.
- Check that IAT sensor signal voltage is 5 V between IAT sensor connector and vehicle body ground.
Is it in good condition? |
Go to Step 4. |
Substitute a known-good ECM and recheck. |
| 4 |
IAT sensor check
- Check IAT sensor for performance referring to MASS AIR FLOW (MAF) AND INTAKE AIR TEMPERATURE (IAT) SENSOR ON-VEHICLE INSPECTION
.
Is it in good condition? |
Substitute a known-good ECM and recheck. |
Replace MAF and IAT sensor. |