DTC P0140:00 [MZR 2.0 DISI i-stop]


id0102d4702700

DTC P0140:00

HO2S circuit no activity detected

DETECTION CONDITION
•  The PCM monitors the input voltage from the HO2S when the following conditions are met. Under the following monitoring conditions, if the input voltage from the HO2S does not even exceed 0.55 V though the short term fuel trim is controlled up to 20.5% for 9.6 s, the PCM determines that the sensor circuit is not activated.
MONITORING CONDITIONS
―  Drive Mode 03 (A/F sensor, HO2S, A/F sensor heater, HO2S heater and TWC repair verification drive mode)
―  The following conditions are met for above 20.8 s:
•  Engine speed: above 1,500 rpm
•  Engine coolant temperature: above 70 °C {158 °F}
•  HO2S voltage: above 0.1V
Diagnostic support note
•  This is an intermittent monitor (A/F sensor, HO2S).
•  The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
•  PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle.
•  FREEZE FRAME DATA (Mode 2)/Snapshot data is available.
•  The DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  HO2S looseness
•  Exhaust system leakage
•  Short to ground in wiring harness between HO2S terminal A and PCM terminal 2Q
•  Open circuit in wiring harness between HO2S terminal A and PCM terminal 2Q
•  HO2S malfunction
―  HO2S deterioration
•  Engine malfunction (Engine coolant leakage to combustion chamber)
•  Insufficient engine compression
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA (MODE 2)
•  Perform the Freeze Frame PID Data Access Procedure.
•  Is the DTC P0140:00 on FREEZE FRAME DATA (Mode 2)?
Yes
Go to the next step.
No
Go to the troubleshooting procedure for DTC on FREEZE FRAME DATA (Mode 2).
2
VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED
•  Have the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS (A/F sensor, HO2S related) been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
3
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
4
VERIFY RELATED PENDING CODE AND/OR DTC
Note
•  If the fuel monitor, DTC P0132:00 is retrieved, ignore it until DTC P0140:00 is fixed.
•  Switch the ignition to off, then to ON (engine off).
•  Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure.
•  Are any other PENDING CODEs and/or DTCs present?
Yes
Go to the applicable PENDING CODE or DTC inspection.
No
Go to the next step.
5
INSPECT HO2S
•  Is there any malfunction?
Yes
Go to the next step.
No
Go to Step 10.
6
INSPECT INSTALLATION OF HO2S
•  Inspect if the HO2S is loosely installed.
•  Is the HO2S installed securely?
Yes
Go to the next step.
No
Retighten the HO2S securely, then go to Step 12.
7
INSPECT GAS LEAKAGE FROM EXHAUST SYSTEM
•  Visually inspect for the exhaust gas leakage between exhaust pipe and HO2S.
•  Is there any leakage?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 12.
No
Go to the next step.
8
INSPECT HO2S SIGNAL CIRCUIT FOR SHORT TO GROUND
•  Switch the ignition to off.
•  Disconnect the HO2S and PCM connectors.
•  Inspect for continuity between HO2S terminal A (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Repair or replace the wiring harness for a possible short to ground, then go to Step 12.
No
Go to the next step.
9
INSPECT HO2S SIGNAL CIRCUIT FOR OPEN CIRCUIT
•  HO2S and PCM connectors are disconnected.
•  Inspect for continuity between HO2S terminal A (wiring harness-side) and PCM terminal 2Q (wiring harness-side).
•  Is there continuity?
Yes
Replace the HO2S, then go to Step 12.
No
Repair or replace the wiring harness for a possible open circuit, then go to Step 12.
10
INSPECT SEALING OF ENGINE COOLANT PASSAGE
•  Perform the “ENGINE COOLANT LEAKAGE INSPECTION”.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 12.
No
Go to the next step.
11
INSPECT ENGINE COMPRESSION
•  Inspect the engine compression.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to the next step.
No
Go to the next step.
12
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform the Drive Mode 03 (A/F sensor heater, HO2S heater, A/F sensor, HO2S, and TWC Repair Verification Drive Mode).
•  Is the PENDING CODE for this DTC present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
No
Go to the next step.
13
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
DTC troubleshooting completed.