DTC P0140:00 [MZR 1.8, MZR 2.0, MZR 2.5]

id0102f4702700

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 sensor circuit is not activated.
MONITORING CONDITIONS
―  Drive Mode 03 (A/F Sensor Heater, HO2S Heater, A/F Sensor, HO2S and TWC Repair Verification Drive Mode)
―  Following conditions are met for above 20.8 s
•  Engine speed: above 1,500 rpm
•  ECT: above 70 °C {158 °F}
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
•  Leakage exhaust system
•  HO2S connector or terminals malfunction
•  HO2S heater malfunction
•  Short to ground in wiring harness between HO2S terminal A and PCM terminal 2Q
•  PCM connector or terminals malfunction
•  Open circuit in wiring harness between HO2S terminal A and PCM terminal 2Q
•  Engine malfunction
―  Engine coolant leakage to combustion chamber
―  Insufficient engine compression
•  HO2S malfunction
―  HO2S deterioration
•  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).
(See DTC TABLE [MZR 1.8, MZR 2.0, MZR 2.5].)
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.
(See DTC TABLE [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Go to the next step.
5
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, then go to Step 15.
(See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
6
INSPECT GAS LEAKAGE FROM EXHAUST SYSTEM
•  Visually inspect for the exhaust gas leakage between exhaust manifold and HO2S.
•  Is there any leakage?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 15.
No
Go to the next step.
7
INSPECT HO2S CONNECTOR CONDITION
•  Switch the ignition to off.
•  Disconnect the HO2S connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 15.
No
Go to the next step.
8
INSPECT HO2S HEATER
•  Inspect the HO2S heater.
•  Is there any malfunction?
Yes
Replace the HO2S, then go to Step 15.
(See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Go to the next step.
9
INSPECT HO2S SIGNAL CIRCUIT FOR SHORT TO GROUND
•  HO2S connector is disconnected.
•  Inspect for continuity between HO2S terminal A (wiring harness-side) and body ground.
•  Is there continuity?
Yes
If the short to ground circuit could be detected:
•  Repair or replace the wiring harness for a possible short to ground.
If the short to ground circuit could not be detected:
•  Replace the PCM (short to ground in the PCM internal circuit).
Go to Step 15.
No
Go to the next step.
10
INSPECT PCM CONNECTOR CONDITION
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 15.
No
Go to the next step.
11
INSPECT HO2S SIGNAL CIRCUIT FOR OPEN CIRCUIT
•  HO2S and PCM connecters are disconnected.
•  Inspect for continuity between HO2S terminal A (wiring harness-side) and PCM terminal 2Q (wiring harness-side).
•  Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open circuit, then go to Step 15.
12
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 15.
No
Go to the next step.
13
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 Step 15.
No
Go to the next step.
14
INSPECT HO2S
•  Switch the ignition to off.
•  Reconnect all disconnected connectors.
•  Inspect the HO2S.
•  Is there any malfunction?
Yes
Replace the HO2S, then go to the next step.
(See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Go to the next step.
15
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform the KOER self test.
•  Is the PENDING CODE for this DTC present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Go to the next step.
16
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 1.8, MZR 2.0, MZR 2.5].)
No
DTC troubleshooting completed.