Diagnostic Trouble Code (DTC) P0141

Rear Heated Oxygen Sensor Heater Malfunction

                          

 

 

                                                    Features of the Circuit

  • A voltage approximately of 450mm volts is generated by the ECM between the ECM terminals 44 and 13.
  • If the Exhaust Is RICH:    The Heated oxygen (O2) sensor is devised to alter the voltage between a range of about 1volt.
  • If the Exhaust Is POOR:  The Heated oxygen (O2) sensor is devised to alter the voltage between a range of about 100mm volt.
  • The Heated O2 sensor acts quite like an open circuit and does not generate any voltage when it is below 360°C(600°F).
  • An "open loop" operation is created by an open O2 sensor circuit or a cold O2 sensor

 

                          

 

                                    QUESTION: When Does DTC Set?

                                    ANSWER:  DTC sets
                               1)when the heated O2 sensor heater resistance is < 10ohms
                                                       or 
                                 2) > 30 ohms   

                                                    

 

Task Boosted When DTC sets

When Does DTC clear?

1) The Malfunction Indicator Lamp (MIL) will be seen glowing after three failed repetitive trips.

 

1)   The MIL will stop work after four repetitive ignition cycles where the diagnostic functions flawlessly.

 

2) The ECM is devised to record operating conditions at the time the diagnostic fails which will be stored in the Freeze Frame and Failure Records will be boosted.

 

2)  A history DTC will clear after 40 consecutive warm-up cycles without a fault

3) A history DTC is stored.

 

3)  The Scan Tool can be made use of in order to clear all DTCs

    4)  The coolant fan turns ON

4) Disconnecting the ECM battery feed for more than 10 seconds

 

 

 

Diagnostic Help

  • You will find that the normal scan tool voltage fluctuates around 0.1volts and 0.9 volts if in closed loop.
  • Examine the oxygen (O2) sensor wire in order to find out whether the O2 sensor may be positioned inaccurately or in contact with the exhaust manifold.
  • Probe to detect if any an intermittent ground in the wire between the O2 sensor and the engine control module is existing.
  • Carry out an injector balance test to note if a restricted fuel injector is the cause of a lean condition.
  • Vacuum of crankcase leaks may be the source of a lean running condition.
  • If an exhaust manifold gasket leak of a cracked exhaust manifold is existing then it may  set  outside air to be sucked into the exhaust and even beyond the sensor.

 

 

STEPS TO DETERMINE THIS DTC

DTC P0141 - Rear Heated Oxygen Sensor Heater Malfunction

 

Step

Task

Positive

Negative

1

Carry out an EOBD System Check.

 

Task Complete?

Look up Step 2

Look up "On-Board Diagnostic System Check"

2

  1. LOCK the ignition switch.
  2. De-link  the Heated O2 sensor and the ECM connectors.
  3. Probe the Heated O2 sensor heater wire between the Heated O2 sensor connector terminal 4 and ECM connector terminal 64 to look for an open or short to ground.

Do you see any discrepancy existing?

Look up Step 3

Look up Step 4

3

  1. Mend the wire of the connector terminal as needed.
  2. Unset the DTCs from the ECM.
  3. Test the vehicle by running it on the road.
  4. Execute the diagnostic system check.

Task done?

The System of the engine is perfect.

-

4

  1. LOCK the ignition switch.
  2. Substitute the Heated O2 sensor.
  3. Test the vehicle by running it on the road.
  4. Execute the diagnostic system check.

Task done?

Look up Step 6

-

5

Probe whether any additional DTCs remain set.

 

Do you see any undiagnosed DTCs being exhibited?

Look up applicable DTC table

The System of the engine is perfect.