[ 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. P0138 OXYGEN SENSOR (REAR) CIRCUIT HIGH VOLTAGE
Code No. P0138: Oxygen Sensor (rear) Circuit High 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
  • More than 2 seconds have passed since the engine starting sequence was completed.
  • Oxygen sensor (rear) offset voltage is more than 0.4 V and is less than 3.8 V.
Judgement Criterion
  • Oxygen sensor (rear) output voltage is more than 1.2 V for 2 seconds.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • None
 
 
PROBABLE CAUSES
  • Failed oxygen sensor (rear)
  • Short circuit 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)
Are the check results 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. Check of short circuit in O2RL line between oxygen sensor (rear) connector and engine-ECU connector.
Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness.
 
STEP 3. Check of 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.