| 1 |
Was "Engine and Emission Control System Check" performed? |
Go to Step 2. |
Go to ENGINE AND EMISSION CONTROL SYSTEM CHECK . |
| 2 |
HO2S 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 (bank-1) output voltage displayed on scan tool.
Does HO2S output voltage between 0.5 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 Step 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 circuit check
- Disconnect connector from HO2S (bank-1) and ECM with ignition switch turned OFF.
- Check for proper terminal connection to HO2S (bank-1) connector and ECM connector.
- If connections are OK, check that HO2S (bank-1) circuit is as follows.
- Wiring harness resistance of each "Signal circuit of HO2S (bank-1)", "Ground circuit of HO2S (bank-1)" and "Control circuit of HO2S (bank-1) heater" is less than 1 Ω.
- Insulation resistance between "Signal circuit of HO2S (bank-1)" and vehicle body ground is infinity.
- Insulation resistance of wire harness is infinity between "Signal circuit of HO2S (bank-1)" terminal and each other terminal at HO2S (bank-1) connector.
- Circuit voltage between "Signal circuit of HO2S (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 heater check
- Check heater resistance of HO2S (bank-1) referring to HEATED OXYGEN SENSOR (HO2S-2) HEATER ON-VEHICLE INSPECTION
.
Is HO2S heater in good condition? |
Go to Step 7. |
Replace HO2S (bank-1). |
| 7 |
A/F sensor circuit check
- Disconnect connectors from A/F sensor (bank-1) with ignition switch turned OFF.
- Check for proper terminal connection to A/F sensor (bank-1) connector and ECM connector.
- If connections are OK, check that A/F sensor (bank-1) circuit is as follows.
- Wiring harness resistance of each "Signal (+) circuit of A/F sensor (bank-1)", "Signal (-) circuit of A/F sensor (bank-1)", "Control circuit of A/F sensor (bank-1) heater" and "Control ground circuit of A/F sensor (bank-1) heater" is less than 1 Ω.
Is it in good condition? |
Go to Step 5. |
Repair or replace defective wiring harness. |
| 8 |
A/F sensor adjusting resistor circuit check
- Check that A/F sensor (bank-1) adjusting resistor circuit is as follows.
- Wiring harness resistance of each "Adjusting resistor (+) circuit of A/F sensor (bank-1)" and "Adjusting resistor (-) circuit of A/F sensor (bank-1)" is less than 1 Ω.
- Insulation resistance between "Adjusting resistor (+) circuit of A/F sensor (bank- 1)" wire terminal and vehicle body ground is infinity.
- Insulation resistance between "Adjusting resistor (+) circuit of A/F sensor (bank- 1)" and "Adjusting resistor (-) circuit of A/F sensor (bank-1)" is infinity.
- Circuit voltage between "Adjusting resistor (+) circuit of A/F sensor (bank-1)" and vehicle body ground is 0 V with ignition switch tuned ON.
Are they in good condition? |
Go to Step 6. |
Repair or replace defective wiring harness. |
| 9 |
A/F sensor check
- Check for A/F sensor (bank-1) referring to AIR FUEL RATIO (A/F) SENSOR ON-VEHICLE INSPECTION
.
Is check result satisfactory? |
Go to Step 10. |
Replace A/F sensor (bank-1). |
| 10 |
Valves and valves clearance check
- Check bank-1 intake & exhaust valve and valve clearance referring to VALVE LASH (CLEARANCE) INSPECTION
and VALVES AND VALVE GUIDES INSPECTION
.
Is check result satisfactory? |
Substitute a known-good HO2S (bank-1) and recheck. If HO2S (bank-1) OK, replace A/F sensor (bank-1). |
Repair or replace defective parts. |