DTC Troubleshooting
DTC DIAGNOSTIC 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 |
HO2S-2 signal check
- Connect scan tool with ignition switch turned OFF.
- Warm up engine to normal operating temperature and keep it at 2000 r/min. for 60 sec.
- Repeat racing engine (Repeat depressing accelerator pedal 5 to 6 times continuously to enrich A/F mixture and take foot off from pedal to enlean it).
- Check for HO2S-2 (bank-1) average output voltage displayed on scan tool.
Does HO2S-2 average output voltage indicate within 0.35 V and 0.8 V? |
Intermittent trouble. Check for intermittent referring to INTERMITTENT AND POOR CONNECTION INSPECTION
. |
Go to Step 3. |
| 3 |
Intake system and exhaust system for leakage check
- Check intake system and exhaust system for leakage.
Are intake system and exhaust system in good condition? |
Go to 4. |
Repair or replace defective parts. |
| 4 |
Fuel injectors and its circuit check
- Check each bank-1 fuel injectors referring to FUEL INJECTOR INSPECTION
.
Is check result satisfactory? |
Go to Step 5. |
Faulty injector(s) or its circuit. |
| 5 |
HO2S-2 circuit check
- Disconnect connector from HO2S-2 (bank-1) and ECM with ignition switch turned OFF.
- Check for proper terminal connection to HO2S-2 (bank-1) connector and ECM connector.
- If connections are OK, check that HO2S-2 (bank-1) circuit is as follows.
- Wiring harness resistance of each "Signal circuit of HO2S-2 (bank-1)", "Ground circuit of HO2S-2 (bank-1)" and "Control circuit of HO2S-2 (bank-1) heater" is less than 1 Ω.
- Insulation resistance between "Signal circuit of HO2S-2 (bank-1)" and vehicle body ground is infinity.
- Circuit voltage between "Signal circuit of HO2S-2 (bank-1)" and vehicle body ground is 0 V with ignition switch turned ON.
Are they in good condition? |
Go to Step 6. |
Repair or replace defective wiring harness. |
| 6 |
HO2S-2 check
- Check HO2S-2 (bank-1) referring to Step 3 of DTC P0137 / P0138: O2 Sensor (Bank 1 Sensor-2) Circuit Low Voltage / High Voltage .
Is HO2S-2 in good condition? |
Substitute a known-good ECM and recheck. |
Substitute a known-good HO2S-2 (bank-1) and recheck. If HO2S-2 (bank-1) is OK, go Step7. |
| 7 |
Valves and hydraulic valve lash adjusters check
- Check bank-1 intake & exhaust valve and hydraulic valve lash adjuster referring to VALVES AND VALVE GUIDES INSPECTION
and VALVE LASH ADJUSTERS INSPECTION
.
Is check result satisfactory? |
Substitute a known-good ECM and recheck. |
Repair or replace defective parts. |