Mitsubishi Galant 9G. Manual - part 1221

ON-VEHICLE SERVICE

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1184

HEATED OXYGEN SENSOR CHECK

M1131005000691

Required Special Tools:

• MB991958: Scan tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

• MB991316: Test Harness 

• MD998464: Test Harness

.

<Right bank and left 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) and terminal No. 

3 (blue clip) 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) 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) <3.8L ENGINE>

13B-1185

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 

8V 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 oxy-
gen sensor with a (+) terminal and (-) terminal of 8 V power 
supply respectively, then check again.
3. If the output voltage is not within the standard value, 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.15-20

.

.

<Right bank and left 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) and terminal No. 

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

2. While repeatedly revving the engine, measure the heated 

oxygen sensor output voltage.

Standard value:

AKX01624 AB

MB991316

HEATED
OXYGEN
SENSOR
EQUIPMENT
SIDE
CONNECTOR

BLUE

RED

AKX01625 AB

BLUE

JUMPER
WIRES

BLACK

RED

WHITE

MB991316

ON-VEHICLE SERVICE

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1186

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 

8V is applied to the oxygen sensor heater.

3. If the output voltage is not within the standard value, replace 

the heated oxygen sensor.

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 terminal No. 1 
of the oxygen sensor with a (+) terminal and (-) terminal of 12 V 
power supply respectively, then check again.
NOTE: For removal and installation of the heated oxygen sen-
sor, refer to GROUP 15, Exhaust Pipe and Main Muffler 

P.15-20

.

INJECTOR CHECK

M1131005200521

.

<Right bank side (number 1, 3, 5 cylinders)>

1. Disconnect the intermediate connector B-32.
2. Measure the resistance between the injector intermediate 

connector terminals.

Standard value:

3. Connect the injector intermediate connector.

.

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.

INJECTOR NO.

MEASUREMENT 
TERMINAL

RESISTANCE

NO.1

5 

− 9

10.5 

− 13.5 Ω [20°C 

(68

°F)]

NO.3

9 

− 10

NO.5

4 

− 9

1

2 3

6

7 8

4 5

9 10

AK203093

B-32 
INTERMEDIATE
CONNECTOR

AB

ON-VEHICLE SERVICE

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1187

<Left bank side (number 2, 4, 6 cylinders)>

1. Disconnect the injector connector.
2. Measure the resistance between injector side connector 

terminals 1 and 2.

Standard value: 10.5 

− 13.5 ohms [at 20°C (68°F)]

3. Connect the injector connector.

THROTTLE ACTUATOR CONTROL MOTOR 
CHECK

M1131051000070

.

<Operation Inspection>

1. Disconnect the air intake hose from the throttle body.
2. Set the ignition switch to the "ON" position.
3. Operate the accelerator pedal and confirm that the throttle 

valve is opening and closing accordingly.

.

<Checking the Terminal Resistance>

1. Disconnect the throttle position sensor connector.
2. Measure the resistance between terminal No. 1 and No. 2.

Standard value: 0.3 

− 80 ohms [at 20°C (68°F)]

3. If resistance is outside the standard value, replace the 

throttle body assembly.

EVAPORATIVE EMISSION PURGE SOLENOID 
CHECK

M1131005600240

Refer to GROUP 17, Emission Control System 

− Evaporative 

Emission System 

− Evaporative Emission Purge Solenoid 

Check 

P.17-87

.

EVAPORATVE EMISSION VENTILATION 
SOLENOID CHECK

M1131012800224

Refer to GROUP 17, Emission Control System 

− Evaporative 

Emission Canister and Fuel Tank Pressure Relief Valve 

− 

Evaporative Emission Canister and Fuel Tank Pressure Relief 
Valve Inspection 

P.17-96

.

AK000126

6

1 2 3 4 5

AK202992

THROTTLE ACTUATOR
CONTROL MOTOR 
CONNECTOR

AB