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Code No. P0130:
Oxygen Sensor System <DOHC>
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OPERATION
- The sensor signal is inputted to the engine-A/T-ECU (terminal
No. 71) from the oxygen sensor output terminal (terminal No. 4).
- The oxygen sensor (terminal No. 3) is earthed with engine-A/T-ECU (terminal No.
57).
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function
- The oxygen sensor converts the concentration of oxygen
in the exhaust emission into a voltage and inputs the signal to the engine-A/T-ECU.
- When the air-fuel ratio is richer than the theoretical air-fuel ratio, the oxygen
sensor outputs a voltage of about 1 V. When it is leaner than the theoretical air-fuel ratio,
it outputs a voltage of about 0 V.
- In response to the signal, the engine-A/T-ECU controls the fuel infection amount
so that the air-fuel ratio can be equivalent to the theoretical air-fuel ratio.
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TROUBLE JUDGMENT
Check Condition
- After 3 or more minutes from when the engine has started up.
- Engine coolant temperature approximately 80 °C or more.
- Volumetric efficiency 25%
or more.
- Engine speed of 1,200 r/min or more.
Judgment Criterion
- When the oxygen sensor output voltage is 0.2 V or less, and a power voltage of 5
V is applied to the oxygen sensor in the engine-A/T-ECU, the sensor output voltage is 4.5 V
or more.
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PROBABLE CAUSE
- Open/short circuit in oxygen sensor circuit or loose connector contact
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| STEP 1. MUT-II/III data list
- Refer to Data list reference table
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Q: Is the check result normal?
YES:
Intermittent malfunction (Refer to GROUP 00 -
How to Use Troubleshooting/Inspection
Service Points  ).
NO:
Go to Step 2  .
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| STEP 2. Connector check: C-18 oxygen sensor connector
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Q: Is the check result normal?
YES:
Go to Step 3  .
NO:
Repair.
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| STEP 3. Perform resistance measurement at C-18 oxygen sensor connector
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- Disconnect connector, and measure at harness side.
- Resistance between terminal No. 3 and earth.
OK: 2 Ω
or less
Q: Is the check result normal?
YES:
Go to Step 7  .
NO:
Go to Step 4  .
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| STEP 4. Connector check: C-111 engine-A/T-ECU connector
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Q: Is the check result normal?
YES:
Go to Step 5  .
NO:
Repair.
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| STEP 5. Check harness between C-18 (terminal No. 3) oxygen sensor
connector and C-111 (terminal No. 57) engine-A/T-ECU connector.
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- Check earthing line for open circuit and damage.
Q: Is the check result normal?
YES:
Go to Step 6  .
NO:
Repair.
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| STEP 6. MUT-II/III data list
- Refer to Data list reference table
.
Q: Is the check result normal?
YES:
Intermittent malfunction (Refer to GROUP 00 -
How to Use Troubleshooting/Inspection
Service Points  ).
NO:
Replace engine-A/T-ECU.
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| STEP 7. Perform voltage measurement at C-18 oxygen sensor connector.
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- Use special tool test harness (MB991658) to connect connector, and measure
at pick-up harness.
- Voltage between terminal No. 3 and earth.
OK: 0.5V or less
Q: Is the check result normal?
YES:
Go to Step 9  .
NO:
Go to Step 8  .
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| STEP 8. Connector check: C-111 engine-A/T-ECU connector
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Q: Is the check result normal?
YES:
- Check and repair harness between C-18 (terminal No.
3) oxygen sensor connector and C-111 (terminal No. 57) engine-A/T-ECU connector.
- Check earthing line for damage.
NO:
Repair.
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| STEP 9. Perform voltage measurement at C-18 oxygen sensor connector.
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- Use special tool test harness (MB991658) to connect connector, and measure
at pick-up harness.
- Voltage between terminal No. 4 and earth.
OK:
- 600 -
1,000 mV when 200 mV or lower abrupt racing is done a few seconds
after abrupt deceleration from 4,000 r/min.
Q: Is the check result normal?
YES:
Go to Step 12  .
NO:
Go to Step 10  .
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| STEP 10. Check oxygen sensor itself
- Check oxygen sensor itself (Refer to
).
Q: Is the check result normal?
YES:
Go to Step 11  .
NO:
Replace oxygen sensor.
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| STEP 11. Connector check: C-110 engine-A/T-ECU connector
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Q: Is the check result normal?
YES:
- Check and repair harness between C-18 (terminal No.
4) oxygen sensor connector and C-110 (terminal No. 71) engine-A/T-ECU connector.
- Check output line for damage.
NO:
Repair.
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| STEP 12. Perform voltage measurement at C-110 engine-A/T-ECU connector.
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- Measure engine-A/T-ECU terminal voltage.
- Selector lever position: P
- Voltage between terminal No. 71 and earth.
OK:
- 600 -
1,000 mV when 200 mV or lower abrupt racing is done a few seconds
after abrupt deceleration from 4,000 r/min.
Q: Is the check result normal?
YES:
Go to Step 14  .
NO:
Go to Step 13  .
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| STEP 13. Connector check: C-110 engine-A/T-ECU connector
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Q: Is the check result normal?
YES:
- Check and repair harness between C-18 (terminal No.
4) oxygen sensor connector and C-110 (terminal No. 71) engine-A/T-ECU connector.
- Check output line for open circuit.
NO:
Repair.
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| STEP 14. Connector check: C-110 engine-A/T-ECU connector
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Q: Is the check result normal?
YES:
Go to Step 6  .
NO:
Repair.
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