California
Right Bank Heated Oxygen Sensor (rear) Circuit:
CIRCUIT OPERATION
- A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the ECM (terminal 74)
- Terminal 2 of the right bank heated oxygen sensor (rear) is grounded with ECM (terminal 49)
TECHNICAL DESCRIPTION
- The output signal of the right bank heated oxygen sensor (front) is compensated by the output signal of the right bank heated oxygen sensor (rear).
- The ECM
DTC SET CONDITIONS
Check Conditions
- Right bank heated oxygen sensor (rear) signal voltage has continued to be 0.15 volt or lower for three minutes or more after the starting sequence was completed.
- Engine coolant temperature is higher than 82°C (180°F).
- Engine speed is higher than 1,200 r/min.
- Volumetric efficiency is higher than 25 percent.
- Monitoring time: 7 seconds.
Judgment Criteria
- Input voltage supplied to the ECM
- Only one monitor during one drive cycle
Check Conditions
- Right bank heated oxygen sensor (rear) signal voltage remains 0.15 volt or less for at least three minutes after the engine starts.
- Engine coolant temperature is higher than 82°C (180°F).
- Engine speed is higher than 1,200 r/min.
- Volumetric efficiency is higher than 25 percent.
- Volume air flow sensor output frequency is 75 Hz or more.
- At least twenty seconds have passed since fuel shut off control was canceled.
- The right bank heated oxygen sensor (front) outputs 0.5 volts or more.
- Monitoring time: 10 seconds
Judgement Criteria
- Making the air/fuel ratio 15 percent for 10 seconds richer does not result in raising the right bank heated oxygen sensor (rear) output voltage beyond 0.15 volt.
- Only one monitor during one drive cycle
Check Conditions
- Engine coolant temperature is higher than 82°C (180°F).
- Barometric pressure is higher than 76 kPa (11 psi).
- The right bank heated oxygen sensor (front) is active.
Judgement Criteria
- The right bank heated oxygen sensor (rear) output voltage is 0.4 volt or more when fuel begins to be shut off. Then at least one second elapses until the voltage reduces to 0.15 volt or less while fuel is being shut off.
or
- The right bank heated oxygen sensor (rear) output voltage is 0.15 volt or more when fuel begins to be shut off. Then at least three seconds elapse until the voltage reduces to 0.15 volt or less while fuel is being shut off.
TROUBLESHOOTING HINTS
The most likely causes for this code to be set are:
- Right bank heated oxygen sensor (rear) failed.
- Open circuit in right bank heated oxygen sensor (rear) output line.
- Open circuit in right bank heated oxygen sensor (rear) ground line.
- ECM failed.
- PCM failed.
DIAGNOSIS
Required Special Tool:
MB991502: Scan Tool (MUT-II)
MB991316: Test Harness
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
STEP 1. Using scan tool MB991502, check data list item 59: Heated Oxygen Sensor (rear).
1. Connect scan tool MB991502 to the data link connector.
2. start the engine and run at idle.
3. Set scan tool MB991502 to the data reading mode for item 59, Heated Oxygen Sensor (rear).
- Warm up the engine. When the engine is revved, the output voltage should repeal 0 volt and 0.6 to 1.0 volt alternately.
If the checks above meet the specification, this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope With Intermittent Malfunction.
If the checks above do not meet the specification, go to Step 2.
STEP 2. Check the right bank heated oxygen sensor (rear).
1. Disconnect the right bank heated oxygen sensor connector (rear) B-28 and connect test harness special tool, MD991316, to the right bank heated oxygen sensor (rear) side.
2. Warm up the engine until engine coolant is 80°C (176°F) or higher.
CAUTION: Be very careful when connecting the jumper wires; incorrect connection can damage the right bank heated oxygen sensor (rear).
3. Use the jumper wires to connect terminal 1 (red clip) of the right bank heated oxygen sensor (rear) connector to the battery (+) terminal and terminal 3 (blue clip) to the battery (-) terminal.
4. Connect a digital voltage meter between terminal 2 (black clip) and terminal 4 (white clip).
5. While repeatedly revving the engine, measure the right bank heated oxygen sensor (rear) output voltage.
Standard value: 0.6 - 1.0 V
If within specifications, go to Step 3.
If not within specifications, replace the heated oxygen sensor (rear). 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 the harness connector B-28 is damaged, repair or replace
it. Refer to Harness Connector Inspection. Then go to Step 7.
STEP 4. Check harness connectors C-58, C-62 at the ECM
If harness connectors C-58, C-62
If harness connectors C-58, C-62
Refer to Harness Connector Inspection. Then go to Step 7.
STEP 5. Check the harness wire between the right bank heated oxygen sensor (rear) connector B-28 and the ECM connector C-58, C-62
If the wires between heated oxygen sensor (rear) connector B-28 and ECM connector C-58, C-62
If the wire between the right bank heated oxygen sensor (rear) connector B-28 and ECM connector C-58, C-62
STEP 6. Replace the right bank heated oxygen sensor (rear).
1. Replace the right bank heated oxygen sensor (rear).
2. Carry out a test drive with the drive cycle pattern. Refer to Procedure 4 - Heated Oxygen Sensor Monitor and Procedure 6 - Other Monitor.
3. Check for the diagnostic trouble code (DTC).
If DTC P0136 is not output, the inspection is complete.
If DTC P0136 is output, 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 4 - Heated Oxygen Sensor Monitor and Procedure 6 - Other Monitor.
2. Read the diagnostic trouble code, and confirm that diagnostic trouble code P0136 does not reset.