Mitsubishi Montero Sport (2004+). Manual — part 370

ON-VEHICLE SERVICE

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-893

<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 tracing 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 of special tool) and terminal No. 4 (white clip of
special tool).

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 oxygen sensor.

• Be careful the heater is broken when voltage of beyond

8 volts is applied to the oxygen sensor heater.

NOTE: If the sufficiently high temperature (of approximate
400

°

C or more) is not reached although the oxygen sensor

is normal, the output voltage would be possibly low although
the rich air-fuel ratio. Therefore, if the output voltage 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 oxygen sensor with a (+) terminal and (-) terminal of 8
volts power supply respectively, then check again.

ENGINE

HEATED
OXYGEN
SENSOR
OUTPUT
VOLTAGE

REMARKS

When revving
engine

0.6

− 1.0 volt

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 volt.

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-894

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.15-10

.

.

<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 tracing 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 of special tool) and terminal No. 4 (white clip of
special tool).

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 volt

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 volt.

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-895

CAUTION

• Be very careful when connecting the jumper wire;

incorrect connection can damage the oxygen sensor.

• Be careful the heater is broken when voltage of beyond

12volts is applied to the oxygen sensor heater.

NOTE: If the sufficiently high temperature (of approximate
400

°

C or more) is not reached although the oxygen sensor

is normal, the output voltage would be possibly low although
the rich air-fuel ratio. Therefore, if the output voltage is low,
use a jumper wire to connect the terminal No.2 and the ter-
minal No. 1 of the oxygen sensor with a (+) terminal and (-)
terminal of 12 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.15-10

.

.

<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 tracing 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 of special tool) and terminal No. 4 (white clip of
special tool).

AKX01624 AB

MB991316

HEATED
OXYGEN
SENSOR
EQUIPMENT
SIDE
CONNECTOR

BLUE

RED

AKX01624

HEATED
OXYGEN
SENSOR
COMPONENT
SIDE
CONNECTOR

MB991316

WHITE

BLACK

AN

ON-VEHICLE SERVICE

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-896

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 oxygen sensor.

• Be careful the heater is broken when voltage of beyond

12 volts is applied to the oxygen sensor heater.

NOTE: If the sufficiently high temperature (of approximate
400

°

C or more) is not reached although the oxygen sensor

is normal, the output voltage would be possibly low although
the rich air-fuel ratio. Therefore, if the output voltage is low,
use a jumper wire to connect the terminal No.2 and the ter-
minal No. 1 of the oxygen sensor with a (+) terminal and (-)
terminal of 12 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.15-10

.

ENGINE

HEATED
OXYGEN
SENSOR
OUTPUT
VOLTAGE

REMARKS

When revving
engine

0.6

− 1.0 volt

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 volt.