Mitsubishi Outlander XL. Manual - part 270

DTC P0157: Heated Oxygen Sensor Circuit Low Voltage (bank 2, sensor 2)

M11310100198USA0000010000

ZK602841

1

2

3 4 5 6 7 8 9 10 11 12 13 14 15 16

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

2

1

4

3

0.5 V

AA00

ENGINE
CONTROL
MODULE

LEFT BANK HEATED
OXYGEN SENSOR (REAR)

FROM MFI RELAY

TO ECM

1

2

3

4

41

YELLO

W

ORANGE

40

LEFT BANK HEATED OXYGEN SENSOR (REAR) CIRCUIT

B-10

B-13

MU802665

MULTIPORT INJECTION SYSTEM (MFI) <DIAGNOSIS>

13Ab-275

DIAGNOSTIC TROUBLE CODE PROCEDURES

ZK603595AA00

Left bank heated
oxygen sensor (rear)

Front
exhaust pipe 

B-13 (GR)

Connector: B-13

ZK603591

ECM

B-10 (GR)

Connector: B-10

AA00

 

CIRCUIT OPERATION

｠

A  voltage  corresponding  to  the  oxygen
concentration in the exhaust gas is sent to the ECM
(terminal No. 40) from the output terminal (terminal
No. 4) of the left bank heated oxygen sensor (rear).

｠

Terminal  No.  2  of  the  left  bank  heated  oxygen
sensor (rear) is grounded with ECM (terminal No.
41).

｠

The  ECM  applies  an  offset  voltage  of  0.5  volt  to
terminal No. 2 of the left bank heated oxygen sensor
(rear).

TECHNICAL DESCRIPTION

｠

The  output  signal  of  the  left  bank  heated  oxygen
sensor (front) is compensated by the output signal
of the left bank heated oxygen sensor (rear).

｠

The  ECM  check  for  the  left  bank  heated  oxygen
sensor (rear) output voltage.

DESCRIPTIONS OF MONITOR METHODS
Left bank heated oxygen sensor (rear) out put voltage
is under the specified range.

MONITOR EXECUTION

Continuous

MONITOR EXECUTION CONDITIONS (Other
monitor and Sensor)

Other Monitor (There is no temporary DTC stored in
memory for the item monitored below)

｠

Heated oxygen sensor heater (front) monitor

｠

Heated oxygen sensor heater (rear) monitor

｠

Air/fuel ratio feedback monitor

Sensor (The sensor below is determined to be
normal)

｠

Mass airflow sensor

13Ab-276

MULTIPORT INJECTION SYSTEM (MFI) <DIAGNOSIS>

DIAGNOSTIC TROUBLE CODE PROCEDURES

｠

Engine coolant temperature sensor

｠

Intake air temperature sensor

｠

Barometric pressure sensor

DTC SET CONDITIONS

Logic Flow Chart

End

Malfunction

Yes

Yes

Yes

No

No

No

2secs have passed?

Output voltage

< 0.2V

Monitoring

conditions

Good

Start

ZK603708 AA00

Check Conditions

｠

Heated oxygen sensor offset voltage is between 0.4
and 0.6 volt.

｠

Battery  positive  voltage  is  between  11  and  16.5
volts.

｠

3 minutes or more have passed since the engine
starting sequence was completed.

Judgement Criterion

｠

Left bank heated oxygen sensor output voltage is
lower than 0.2 volt for 2 seconds.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function - OBD-II Drive Cycle -
Pattern 23 P.13Ab-8.

TROUBLESHOOTING HINTS (The most likely
causes for this code to be set are:)

｠

Left bank heated oxygen sensor (rear) failed.

｠

Connector damage.

｠

Harness damage.

｠

ECM failed.

 

MULTIPORT INJECTION SYSTEM (MFI) <DIAGNOSIS>

13Ab-277

DIAGNOSTIC TROUBLE CODE PROCEDURES

DIAGNOSIS

Required Special Tools:

｠

MB991316: Test Harness

STEP 1. Check harness connector B-13 at the left bank
heated oxygen sensor (rear) and harness connector B-10 at
the ECM for damage.

Q:Is the harness connector in good condition?

YES:

 Go to Step 2.

NO:

 Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection P.00E-2. Then go to Step 5.

STEP 2. Check the left bank heated oxygen sensor (rear).

(1)

Disconnect  the  left  bank  heated  oxygen  sensor  (rear)
connector  B-13  and  connect  test  harness  special  tool,
MD991316 to the connector on the left bank heated oxygen
sensor (rear) side.

(2)

Warm  up  the  engine  until  engine  coolant  temperature
reaches 80°C (176°F) or higher.

(3)

Drive at 50 km/h (31 mph) or more for 10 minutes.

(4)

Connect a digital voltage meter between terminal No. 1 (red
clip) and terminal No. 3 (blue clip).

(5)

Measure the output voltage of heated oxygen sensor under
the following driving.

a
.

Transaxle: 2nd speed

b
.

Drive with wide open throttle

c
.

Engine: 3,500 r/min or more

Standard value: 0.6 - 1.0 volts

NOTE: 

If the sufficiently high temperature [of

approximate 400°C (752°F) or more] is not reached
although the heated oxygen sensor is normal, the output
voltage would be possibly low although the rich air/fuel
ratio.

Q:Is the measured resistance between 11 and 18 ohms [at

20°C (68°F)?

YES:

 Go to Step 3.

NO:

 Replace the left bank heated oxygen sensor (rear).

Then go to Step 5.

STEP 3. Check for harness between the left bank heated
oxygen sensor (rear) connector B-13 and ECM connector
B-10.

(1)

Disconnect  the  left  bank  heated  oxygen  sensor  (rear)
connector B-13 and the ECM connector B-10.

(2)

Measure the resistance between the heated oxygen sensor
connector B-13 and the ECM connector B-10.

13Ab-278

MULTIPORT INJECTION SYSTEM (MFI) <DIAGNOSIS>

DIAGNOSTIC TROUBLE CODE PROCEDURES