Mitsubishi Montero (2004+). Manual — part 379

ON-VEHICLE SERVICE

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-1003

CAUTION

• Be very careful when connecting the jumper wire;

incorrect connection can damage the heated oxygen
sensor.

• Be careful the heater is broken when voltage of beyond

8 volts is applied to the heated oxygen sensor heater.

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. Therefore, if the output volt-
age is low, use a jumper wire to connect the terminal No. 1 (red
clip of special tool) and the terminal No. 3 (blue clip of special
tool) of the heated oxygen sensor with the positive terminal and
the negative terminal of 8 volts power supply respectively, then
check again.
3. If the sensor is defective, replace the heated oxygen sensor.
NOTE: For removal and installation of the heated oxygen sen-
sor, refer to GROUP 15, Exhaust Pipe and Main Muffler

P.15-13

.

.

ENGINE

HEATED OXYGEN
SENSOR OUTPUT
VOLTAGE

REMARKS

When revving
engine

0.6

− 1.0 V

If you make the
air/fuel ratio rich by
revving the engine
repeatedly, a
normal heated
oxygen sensor will
output a voltage of
0.6

− 1.0 V.

ON-VEHICLE SERVICE

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-1004

<Right bank heated oxygen sensor (front)>
1. Using scan tool MB991958, observe HO

2

S reading. If

values are unsatisfactory, or if a scan tool is not available,
use the following procedure:

(1) Disconnect the heated oxygen sensor connector and

connect special tool MD998464 to the connector on the
heated oxygen sensor side.

(2) Make sure that there is continuity [4.5

− 8.0 ohms at 20°C

(68

°F)] between terminal No. 1 (red clip of special tool)

and terminal No. 3 (blue clip of special tool) on the heated
oxygen sensor connector

(3) If there is no continuity, replace the heated oxygen

sensor.

(4) Warm up the engine until engine coolant is 80

°C (176°F)

or higher.

(5) Perform a racing for 5 minutes or more with the engine

speed of 4,500 r/min.

(6) Connect a digital voltage meter between terminal No. 2

(black clip) and terminal No. 4 (white clip).

2. While repeatedly revving the engine, measure the heated

oxygen sensor output voltage.

Standard value:

CAUTION

• Be very careful when connecting the jumper wire;

incorrect connection can damage the heated oxygen
sensor.

• Be careful the heater is broken when voltage of beyond

8 volts is applied to the heated oxygen sensor heater.

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. Therefore, if the output volt-
age is low, use a jumper wire to connect the terminal No. 1 (red
clip of special tool) and the terminal No. 3 (blue clip of special
tool) of the heated oxygen sensor with the positive terminal and
the negative terminal of 8 volts power supply respectively, then
check again.
3. If the sensor is defective, replace the heated oxygen sensor.

ENGINE

HEATED OXYGEN
SENSOR OUTPUT
VOLTAGE

REMARKS

When revving
engine

0.6

− 1.0 V

If you make the
air/fuel ratio rich by
revving the engine
repeatedly, a
normal heated
oxygen sensor will
output a voltage of
0.6

− 1.0 V.

AKX01624

HEATED
OXYGEN
SENSOR
EQUIPMENT
SIDE
CONNECTOR

MD998464

BLUE

RED

AC

AKX01624

HEATED
OXYGEN
SENSOR
COMPONENT
SIDE
CONNECTOR

MD998464

WHITE

BLACK

AL

ON-VEHICLE SERVICE

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-1005

NOTE: For removal and installation of the heated oxygen sen-
sor, refer to GROUP 15, Exhaust Pipe and Main Muffler

P.15-13

.

.

<Left bank heated oxygen sensor (rear)>
1. Using scan tool MB991958, observe HO

2

S reading. If

values are unsatisfactory, or if a scan tool is not available,
use the following procedure:

(1) Disconnect the heated oxygen sensor connector and

connect special tool MD998464 to the connector on the
heated oxygen sensor side.

(2) Make sure that there is continuity [11

− 18 ohms at 20°C

(68

°F)] between terminal No. 1 (red clip of special tool)

and terminal No. 3 (blue clip of special tool) on the heated
oxygen sensor connector

(3) If there is no continuity, replace the heated oxygen

sensor.

(4) Warm up the engine until engine coolant is 80

°C (176°F)

or higher.

(5) Perform a racing for 5 minutes or more with the engine

speed of 4,500 r/min.

(6) Connect a digital voltage meter between terminal 2 (black

clip) and terminal No. 4 (white clip).

2. While repeatedly revving the engine, measure the heated

oxygen sensor output voltage.

Standard value:

ENGINE

HEATED OXYGEN
SENSOR OUTPUT
VOLTAGE

REMARKS

When revving
engine

0.6

− 1.0 V

If you make the
air/fuel ratio rich by
revving the engine
repeatedly, a
normal heated
oxygen sensor will
output a voltage of
0.6

− 1.0 V.

AKX01624

HEATED
OXYGEN
SENSOR
EQUIPMENT
SIDE
CONNECTOR

MD998464

BLUE

RED

AC

AKX01624

HEATED
OXYGEN
SENSOR
COMPONENT
SIDE
CONNECTOR

MD998464

WHITE

BLACK

AL

ON-VEHICLE SERVICE

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-1006

CAUTION

• Be very careful when connecting the jumper wire;

incorrect connection can damage the heated oxygen
sensor.

• Be careful the heater is broken when voltage of beyond

8 volts is applied to the heated oxygen sensor heater.

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. Therefore, if the output volt-
age is low, use a jumper wire to connect the terminal No. 1 (red
clip of special tool) and the terminal No. 3 (blue clip of special
tool) of the heated oxygen sensor with the positive terminal and
the negative terminal of 8 volts power supply respectively, then
check again.
3. If the sensor is defective, replace the heated oxygen sensor.
NOTE: For removal and installation of the heated oxygen sen-
sor, refer to GROUP 15, Exhaust Pipe and Main Muffler

P.15-13

.

.

<Right bank heated oxygen sensor (rear)>
1. Using scan tool MB991958, observe HO

2

S reading. If

values are unsatisfactory, or if Scan tool is not available, use
the following procedure:

(1) Disconnect the heated oxygen sensor connector and

connect special tool MB991316 to the connector on the
heated oxygen sensor side.

(2) Make sure that there is continuity [11

− 18 ohms at 20°C

(68

°F)] between terminal No. 1 (red clip of special tool)

and terminal No. 3 (blue clip of special tool) on the heated
oxygen sensor connector

(3) If there is no continuity, replace the heated oxygen

sensor.

(4) Warm up the engine until engine coolant is 80

°C (176°F)

or higher.

(5) Perform a racing for 5 minutes or more with the engine

speed of 4,500 r/min.

(6) Connect a digital voltage meter between terminal No. 2

(black clip) and terminal No. 4 (white clip).

2. While repeatedly revving the engine, measure the heated

oxygen sensor output voltage.

AKX01624 AB

MB991316

HEATED
OXYGEN
SENSOR
EQUIPMENT
SIDE
CONNECTOR

BLUE

RED

AKX01624

HEATED
OXYGEN
SENSOR
COMPONENT
SIDE
CONNECTOR

MB991316

WHITE

BLACK

AN