[ Model - ECLIPSE CROSS / Year - 2018 ]
2018 / ECLIPSE CROSS / EC - Workshop Manual
13 -FUEL > 13A-DIRECT INJECTION AND MULTIPOINT FUEL INJECTION (DI AND MPI) > TROUBLESHOOTING > DIAGNOSIS CODE PROCEDURES > CODE NO. P0137 OXYGEN SENSOR (REAR) CIRCUIT LOW VOLTAGE
Code No. P0137: Oxygen Sensor (rear) Circuit Low Voltage
 
 
 
 
OPERATION
  • The sensor signal is inputted to the engine-ECU connector terminal O2RL from the oxygen sensor (rear) output terminal.
  • The engine-ECU connector terminal ORLE applies an offset voltage of 0.5 V to the oxygen sensor (rear).
 
 
FUNCTION
  • The oxygen sensor (rear) converts the concentration of oxygen in the exhaust emission into a voltage and inputs the signal to the engine-ECU.
  • When the air-fuel ratio is richer than the theoretical air-fuel ratio, the oxygen sensor (rear) 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-ECU controls the fuel injection amount so that the air-fuel ratio can be equivalent to the theoretical air-fuel ratio.
 
 
TROUBLE JUDGEMENT
Check Conditions
  • Oxygen sensor (rear) offset voltage is more than 0.4 V and is less than 0.6 V.
  • Battery positive voltage is more than 11 V and is less than 16.5 V.
  • More than 3 minutes have passed since the engine starting sequence was completed.
Judgement Criterion
  • Oxygen sensor (rear) output voltage is less than 0.2 V for 2 seconds.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • None
 
 
PROBABLE CAUSES
  • Failed oxygen sensor (rear)
  • Open/short circuit or harness damage in oxygen sensor (rear) circuit or loose connector contact
  • Failed engine-ECU
 
 
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-IIISE data list
  • Data list reference table (Refer to ).
    1. Item AD: Oxygen sensor (rear)
Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 2.
 
STEP 2. Perform voltage measurement at oxygen sensor (rear) connector.
  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal engine-ECU ORLE line and body earth.
OK: 0.4 - 0.6 V
Is the check result normal?
Go to Step 5.
Go to Step 3.
 
STEP 3. Check of open circuit, and short circuit in ORLE line between oxygen sensor (rear) connector and engine-ECU connector.
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.
 
STEP 4. M.U.T.-IIISE data list
  • Data list reference table (Refer to ).
    1. Item AD: Oxygen sensor (rear)
Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Replace the engine-ECU.
 
STEP 5. Check of damage in ORLE line between oxygen sensor (rear) connector and engine-ECU connector.
Is the check result normal?
Go to Step 6.
Repair the connector(s) or wiring harness.
 
STEP 6. Perform voltage measurement at oxygen sensor (rear) connector.
  • Use special tool test harness (MB991658) to connect connector, and measure at pick-up harness.
  • Transmission: 2nd
  • Drive with wide open throttle
  • Engine: 3,500 r/min or more
  • Voltage between terminal engine-ECU O2RL line and body earth.
OK:
  • The output voltage should be 1.0 - 1.5 V.
Is the check result normal?
Go to Step 8.
Go to Step 7.
 
STEP 7. Check oxygen sensor (rear) itself.
  • Oxygen sensor check (Refer to ).
Is the check result normal?
Repair the connector(s), or check and repair of short circuit in O2RL line between oxygen sensor (rear) connector and engine-ECU connector.
Replace oxygen sensor (rear).
 
STEP 8. Check of open circuit, and damage in O2RL line between oxygen sensor (rear) connector and engine-ECU connector.
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.