California
Right Bank Heated Oxygen Sensor (rear) Heater Circuit:
Connector : C-51 <M/T>, C-52 <A/T>:
CIRCUIT OPERATION
- Power is supplied from the MFI relay (terminal 1) to the right bank heated oxygen sensor (rear) heater.
- The ECM (terminal 27)
BACKGROUND
- The ECM
DTC SET CONDITIONS
Check Conditions
- Engine coolant temperature is higher than 20°C (68°F).
- While the right bank heated oxygen sensor (rear) heater is on.
- Battery positive voltage is at between 11 and 16 volts.
Judgment Criteria
- Heater current of the right bank heated oxygen sensor (rear) heater has continued to be lower than 0.2 ampere or higher than 3.5 amperes for 6 seconds.
- Only one monitor during one drive cycle
TROUBLESHOOTING HINTS
The most likely causes for this code to be set are:
- Open or shorted right bank heated oxygen sensor (rear) heater circuit.
- Open circuit in right bank heated oxygen sensor (rear) heater.
- ECM failed.
- PCM failed.
DIAGNOSIS
Required Special Tool:
MB991316: Test Harness
STEP 1. Check the right bank heated oxygen sensor (rear).
1. Disconnect the right bank heated oxygen sensor (rear) connector B-28 and connect test harness special tool, MB991316, to the connector on the right bank heated oxygen sensor (rear) side.
2. Measure resistance between right bank heated oxygen sensor (rear) connector terminal 1 (red clip) and terminal 3 (blue clip).
Standard value: 11 - 18 ohms at [20°C (68°F)]
If within specifications, go to Step 2.
If not within specifications, replace the right bank heated oxygen sensor (rear). Then go to Step 7.
STEP 2. Check the power supply line at the right bank heated oxygen sensor (rear) connector B-28.
1. Disconnect connector B-28 and measure at the harness side.
2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminal 1 and ground.
- Voltage should be battery positive voltage.
4. Turn the ignition switch to "LOCK" (OFF) position. If within specifications, go to Step 3.
If not within specifications, repair the harness wire between the MFI relay connector A-21X and the right bank heated oxygen sensor (rear) connector B-28. Then go to Step 7.
STEP 3. Check harness connector B-28 at the right bank heated oxygen sensor (rear) for damage.
If harness connector B-28 is in good condition, go to Step 4
If harness connector C-28 is damaged, repair or replace it.
Refer to Harness Connector Inspection. Then go to Step 7.
STEP 4. Check the circuit at ECM connector C-51
1. Disconnect connector C-51
2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminal 27 and ground.
- Voltage should be battery positive voltage.
4. Turn the ignition switch to "LOCK" (OFF) position.
If within specifications, go to Step 5.
If not within specifications, repair the harness wire between the right bank heated oxygen sensor (rear) connector B-28 and ECM connector C-51
STEP 5. Check harness connector C-51 at the ECM
If harness connector C-51
If harness connector C-51
STEP 6. Check the terminal voltage at ECM connector C-51
1. Connect connector C-51
2. Start the engine and run at idle.
3. Measure voltage between terminal 27 and ground.
Standard value:
9 - 11 V (Engine: warm idle)
9 - B+ (Engine: revving)
4. Turn the ignition switch to "LOCK" (OFF) position. If within specifications, this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope With Intermittent Malfunction.
If not within specifications, replace the ECM or PCM. Then go to Step 7.
STEP 7. Test the OBD-II drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to Procedure 6 - Other Monitor.
2. Read the diagnostic trouble code, and confirm that diagnostic trouble code P0141 does not reset.