DTC P0139:00

HO2S circuit slow response

DETECTION CONDITION

The PCM monitors the rich (0.55 V) to lean (0.3 V) response time of the HO2S. The PCM measures the response time when the following conditions are met. The PCM determines a HO2S response deterioration malfunction when the measured response time is more than 0.12 s (LF)/0.10 s (L5) for 2 of 3 times.
MONITORING CONDITIONS
- Drive Mode 03 (EGR System, A/F sensor heater, HO2S heater, A/F sensor, HO2S and TWC Repair Verification Drive Mode)
- Following conditions are met:
  - During deceleration fuel cut
  - Estimated temperature of the zirconia element inside the HO2S: above 450°C {842°F}
The PCM monitors for a time-out malfunction (when HO2S remains above 0.2 V for longer than a specified period of time during fuel cut control). The PCM measures the amount of time from when the following conditions are met until the HO2S output voltage drops below 0.2 V. The PCM determines a HO2S timeout malfunction when the detected time is more than 4 s for 2 of 3 times.
MONITORING CONDITIONS
- Drive Mode 03 (EGR System, A/F sensor heater, HO2S heater, A/F sensor, HO2S and TWC Repair Verification Drive Mode)
- Following conditions are met:
  - During deceleration fuel cut
  - Estimated temperature of the zirconia element inside the HO2S: above 450°C {842°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 the first drive cycle.
FREEZE FRAME DATA (Mode 2)/Snapshot data is available.
The DTC is stored in the PCM memory.

POSSIBLE CAUSE

HO2S malfunction
- HO2S loose
- Exhaust system leakage
Purge solenoid valve malfunction
Fuel supply system malfunction or improper fuel line pressure
- Fuel leakage on fuel line from fuel distributor to fuel pump
- Fuel filter restricted
- Pressure regulator malfunction
- Fuel pump unit malfunction
Engine malfunction
- Insufficient engine compression
- Engine coolant leakage
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. (See ON-BOARD DIAGNOSTIC TEST ). Is the DTC P0139:00 on FREEZE FRAME DATA (Mode 2)?	Yes	Go to the next step.
1		No	Go to the troubleshooting procedures for DTC on FREEZE FRAME DATA (Mode 2). (See DTC TABLE ).
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.
2		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 REPAIR INFORMATION AVAILABILITY Verify related Service Bulletins and/or on-line repair information availability. Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
3		No	Go to the next step.
4	VERIFY RELATED PENDING CODE AND STORED DTC Switch the ignition to off, then to ON (engine off). Perform the DTC Reading Procedure and Pending Trouble Code Access Procedure. (See ON-BOARD DIAGNOSTIC TEST ). Is the DTC P0443:00 also present?	Yes	Go to the applicable DTC inspection. (See DTC P0443:00 ).
4		No	Go to the next step.
5	INSPECT INSTALLATION OF HO2S Inspect installation of HO2S. Is the HO2S installed securely?	Yes	Go to the next step.
5		No	Retighten the HO2S, then go to Step 17. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION ).
6	INSPECT FOR LEAKAGE FROM EXHAUST SYSTEM Visually inspect if there is any exhaust gas leakage is found between exhaust manifold and HO2S. Is there any leakage?	Yes	Repair or replace Hie malfunctioning part according to the inspection results, then go to Step 17.
6		No	Go to the next step.
7	INSPECT PURGE SOLENOID VALVE Inspect the purge solenoid valve. (See PURGE SOLENOID VALVE INSPECTION ). Is there any malfunction?	Yes	Replace the purge solenoid valve, then go to Step 17. (See PURGE SOLENOID VALVE REMOVAL/INSTALLATION ).
7		No	Go to the next step.
8	INSPECT LONG TERM FUEL TRIM Access the LONGFT1 PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST ). Compare the PID with snapshot data recorded at Step 2. Is it below snapshot data value?	Yes	Engine is driven under rich condition. Go to the next step.
8		No	Engine is driven under lean condition. Go to Step 11.
9	INSPECT FUEL LINE PRESSURE (EXCESSIVE FUEL LINE PRESSURE) Switch the ignition to off. NOTE: If engine will not start, inspect the fuel line pressure with ignition switches to ON. Inspect the fuel line pressure with the engine is running. (See FUEL LINE PRESSURE INSPECTION ). Is there any malfunction?	Yes	Go to the next step.
9		No	Go to Step 14.
10	INSPECT FUEL PUMP Inspect the fuel pump maximum pressure and fuel return pipe for clogging. (See FUEL PUMP UNIT INSPECTION ). Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 17.
10		No	Replace the fuel pump unit, then go to Step 17. (See FUEL PUMP UNIT REMOVAL/INSTALLATION ).
11	INSPECT FUEL LINE PRESSURE (LOW FUEL LINE PRESSURE) Switch the ignition to off. NOTE: If engine will not start, inspect the fuel line pressure with ignition switches to ON. Inspect the fuel line pressure with the engine is running. (See FUEL LINE PRESSURE INSPECTION ). Is there any malfunction?	Yes	Go to the next step.
11		No	Go to Step 14.
12	INSPECT FOR FUEL LINE LEAKAGE Visually inspect for leakage from fuel pump to fuel distributor. Is there any leakage?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 17.
12		No	Go to the next step.
13	INSPECT FUEL FILTER Visually inspect for foreign materials or stain inside fuel filter (low-pressure side). Is there any foreign material or stain?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 17.
13		No	Replace the fuel pump unit, then go to Step 17. (See FUEL PUMP UNIT REMOVAL/INSTALLATION ).
14	INSPECT ENGINE COMPRESSION Inspect the engine compression. (See COMPRESSION INSPECTION ). Is there any malfunction?	Yes	Repair or replace the malfunctioning parts according to the inspection results, then go to Step 17.
14		No	Go to the next step.
15	INSPECT SEALING OF ENGINE COOLANT PASSAGE Perform the "ENGINE COOLANT LEAKAGE INSPECTION". (See ENGINE COOLANT LEAKAGE INSPECTION ). Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 17.
15		No	Go to the next step.
16	INSPECT HO2S Reconnect all disconnected connectors. Inspect the HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION ). Is there any malfunction?	Yes	Replace the HO2S, then go to the next step. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION ).
16		No	Go to the next step.
17	VERIFY DTC TROUBLESHOOTING COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE ). Perform the Drive Mode 03 (EGR System, A/F sensor heater, HO2S heater, A/F sensor, HO2S and TWC Repair Verification Drive Mode). (See OBD-II DRIVE MODE ). Is the PENDING CODE for this DTC present?	Yes	Repeat the inspection from Step 1. If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION ). Go to the next step.
17		No	Go to the next step.
18	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE ). Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE ).
18		No	DTC troubleshooting completed.