P0141
DTC P0141 HO2S HEATER CIRCUIT (BANK 1 / SENSOR 2)Component Location:
GENERAL DESCRIPTION
HO2S (B1/S2) is in the rear side of Catalytic Converter to check the proper operation of catalyst. Oxygen density after the catalytic converter has to be within specific range (around 0.5 V when there is no acceleration and deceleration). If the oxygen density changes in accordance with HO2S (B1/S1), it means the poor performance of catalytic converter.
1DTC DESCRIPTION
If the internal resistance of heater is over the threshold value under enable conditions, ECM/PCM sets DTC P0141.
DTC Detecting Condition:
SPECIFICATION
AIF Ratio Output Voltage (V)
RICH 0.6 - 1.0 V
LEAN 0 - 0.4 V
Schematic Diagram (A/T):
Schematic Diagram (M/T):
Signal Waveform & Data:
MONITOR SCANTOOL DATA
1. Connect scantool to DLC (Data Link Cable).
2. Warm up the engine to normal operating temperature.
3. Monitor "HO2S (B1S2)" parameter on scantool.
4. Is the "HO2S (B1S2)" parameter displayed correctly?
YES - Fault is intermittent caused by poor contact in the sensor's and/or ECM/PCM's connector or was repaired and ECM/PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO - Go to "Terminal and Connector Inspection" procedure.
TERMINAL AND CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminal condition. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES - Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO - Go to "Signal Circuit Inspection" procedure.
POWER CIRCUIT INSPECTION
1. IG "OFF".
2. Disconnect HO2S (B1S2) connector.
3. IG "ON" & ENG "OFF".
4. Measure voltage between terminal 4 of HO2S (B1S2) harness connector and chassis ground.
Specification : B+
5. Is the measured voltage within specification?
YES - Go to "Control Circuit Inspection" procedure.
NO - Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
CONTROL CIRCUIT INSPECTION
1. IG "OFF".
2. Disconnect HO2S (B1S2) connector.
3. IG "ON" & ENG "OFF"
4. Measure voltage between terminal 3 of HO2S (B1S2) harness connector and chassis ground.
Specification : Approx. 3.5 V
5. Is the measured voltage within specification?
YES - Go to "Component Inspection" procedure.
NO - Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
COMPONENT INSPECTION
1. Check Heater resistance.
1. IG "OFF".
2. Disconnect HO2S (B1S2) connector.
3. Measure resistance between terminal 3 and 4 of HO2S (B1S2) connector. (Component Side)
SPECIFICATION :
Item Specification
Heater Resistance Approx. 9.0 at 20 degrees (68 degrees F)
4. Is the measured resistance within specification?
YES
- Substitute with a known - good ECM/PCM and check for proper operation.
- If the problem is corrected, replace ECM/PCM arid go to "Verification of Vehicle Repair" procedure.
NO
- Substitute with a known - good HO2S and check for proper operation.
- If the problem is corrected, replace HO2S and go to "Verification of Vehicle Repair" procedure.
NOTE: There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by ECM/PCM. Before or after testing ECM/PCM on the vehicle, use this function to reuse the ECM/PCM
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode.
2. Clear the DTCs and Operate the vehicle within DTC Enable conditions in General information.
3. Are any DTCs present?
YES - Go to the applicable troubleshooting procedure.
NO - System is performing to specification at this time.