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 |
AF sensor heater circuit check
- Disconnect connector from A/F sensor with ignition switch turned OFF.
- Check for proper terminal connection to A/F sensor connector.
- If connections are OK, measure circuit voltage between "Power supply circuit of A/F sensor heater" and vehicle body ground with ignition switch turned ON.
Is measured voltage 10 - 14 V? |
Go to Step 3. |
Repair or replace defective wiring harness / connector. |
| 3 |
A/F sensor heater circuit check
- Check that A/F sensor heater control circuit is as follows.
- Circuit voltage between "Control circuit of A/F sensor heater" and vehicle body ground is 0 V with ignition switch turned ON.
Is it good condition? |
Go to Step 4. |
Repair or replace defective wiring harness / connector. |
| 4 |
A/F sensor heater circuit check
- Disconnect connectors form ECM and check for proper terminal connection to ECM connector.
- If connections are OK, check that A/F sensor heater circuit is as follows.
- Insulation resistance of wire harness is infinity between "Control circuit of A/F sensor heater" terminal and each other terminal at A/F sensor connector.
- Wiring harness resistance of "Control circuit of A/F sensor heater" and "Control ground circuit of A/F sensor heater" is less than 1 Ω.
- Insulation resistance between "Control circuit of A/F sensor heater" and "Control ground circuit of A/F sensor heater" is infinity.
Are they in good condition? |
Go to Step 5. |
Repair or replace defective wiring harness / connector. |
| 5 |
A/F sensor heater check
- Check heater resistance of A/F sensor referring to AIR FUEL RATIO (A/F) SENSOR ON-VEHICLE INSPECTION
.
Is A/F sensor heater in good condition? |
Substitute a known-good ECM and recheck. |
Replace A/F sensor. |