DTC Description

DTC DETECTION LOGIC

The heated oxygen sensor 2 has a much longer switching time between rich and lean than the air fuel ratio (A/F) sensor 1. The oxygen storage capacity of the three way catalyst 1 causes the longer switching time. To judge the malfunctions of heated oxygen sensor 2, ECM monitors whether the switching response of the sensor's voltage is faster than specified during various driving conditions such as fuel cut.

DTC		M.U.T.-III SE screen terms (Trouble diagnosis content)	DTC detection condition
P0139	00	HO2S2 (B1) (O2 sensor circuit slow response bank 1 sensor 2)	Diagnosis condition	—
			Signal (terminal)	Heated oxygen sensor 2 signal
			Threshold	The switching time between rich and lean of a heated oxygen sensor 2 signal delays more than the specified time computed by ECM
			Diagnosis delay time	—

POSSIBLE CAUSE

Harness or connectors (The sensor circuit is open or shorted.)
Heated oxygen sensor 2
Fuel system
EVAP system
Intake air system

FAIL-SAFE

Not applicable

DTC Confirmation Procedure

1.DTC PRIORITY

If DTC P0139 is detected with DTC P0137 or P0138 perform trouble diagnosis for DTC P0137 or P0138 .

Is applicable DTC detected?

Perform diagnosis of applicable.

DTC P0137: Refer to DTC Description.
DTC P0138: Refer to DTC Description.

2.INSPECTION START

Do you have M.U.T.-III SE?

3.PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.

Turn ignition switch OFF and wait at least 10 seconds.
Turn ignition switch ON.
Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:

For better results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30°C (32 to 86°F).

4.PERFORM DTC CONFIRMATION PROCEDURE

With M.U.T.-III SE

Turn ignition switch ON and select “DATA MONITOR” mode of “ENGINE” using M.U.T.-III SE.
Start engine and warm it up to the normal operating temperature.
Turn ignition switch OFF and wait at least 10 seconds.
Turn ignition switch ON.
Turn ignition switch OFF and wait at least 10 seconds.
Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
Let engine idle for 1 minute.
Make sure that “COOLANT TEMP/S” indicates more than 70°C (158°F).
Drive the vehicle in a proper at 60 km/h (38MPH) and maintain the speed.
caution Always drive vehicle at a safe speed.
Release the accelerator pedal fully at least 5 seconds.
caution
Enable engine brake.
Always drive carefully.
Never apply brake when releasing the accelerator pedal.
Repeat step 9 and 10 at least 8 times.
Check the following item of “DATA MONITOR”.
Data monitor item Status
HO2 S2 DIAG1 (B1) CMPLT
HO2 S2 DIAG2 (B1)

Data monitor item	Status
HO2 S2 DIAG1 (B1)	CMPLT
HO2 S2 DIAG2 (B1)

Is “CMPLT” displayed on M.U.T.-III SE screen?

-1: “CMPLT” is not displayed on DIAG 1Perform DTC confirmation procedure again.

-2: “CMPLT” is not displayed on DIAG 2

5.PERFORM DTC WORK SUPPORT

Open engine hood.
Select “HO2S2 (B1) P0139” in “DTC WORK SUPPORT” mode of “ENGINE” using M.U.T.-III SE.
Start engine and follow the instruction of M.U.T.-III SE display.
note It will take at most 10 minutes until “COMPLETED” is displayed.

Is “COMPLETED” displayed on M.U.T.-III SE screen?

6.PERFORM DTC CONFIRMATION PROCEDURE AGAIN

Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
Perform DTC confirmation procedure again.

7.PERFORM SELF-DIAGNOSIS

With M.U.T.-III SE

Perform ECM self-diagnosis.

Is DTC “P0139” detected?

Proceed to DTC Diagnosis Procedure

-1 To check malfunction symptom before repair: Refer to Intermittent IncidentIntermittent Incident

-2Confirmation after repair:

8.ERASE DTC

Erase DTC of ECM

: INSPECTION END

9.PERFORM COMPONENT FUNCTION CHECK

Perform component function check. Refer to Component Function Check

note	Use component function check to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st trip DTC might not be confirmed.

Is the inspection result normal?

-1 To check malfunction symptom before repair: Refer to Intermittent IncidentIntermittent Incident

-2Confirmation after repair:

Refer to DTC Diagnosis Procedure

10.ERASE DTC

Erase DTC of ECM

: INSPECTION END