Mitsubishi Galant (2004+). Manual - part 1354

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1109

30

Power supply 
voltage applied to 
accelerator pedal 
position sensor 
(main)

Ignition switch: "ON"

4.9 

− 5.1 V

33

Brake lamp switch Depress the brake pedal

B+

Release the brake pedal

1 V or less

41

Fuel tank 
temperature 
sensor

Ignition switch: 
"ON"

When fuel tank temperature 
is 0

°C (32°F)

2.7 

− 3.1 V

When fuel tank temperature 
is 20

°C (68°F)

2.1 

− 2.5 V

When fuel tank temperature 
is 40

°C (104°F)

1.6 

− 2.0 V

When fuel tank temperature 
is 80

°C (176°F)

0.8 

− 1.2 V

42

Backup power 
supply

Ignition switch: "LOCK" (OFF)

B+

43

Ignition switch-IG

Ignition switch: "ON" 

B+

51

Power supply

Ignition switch: "ON"

B+

64
52

MFI relay (power 
supply)

Ignition switch: "LOCK" (OFF)

B+

Ignition switch: "ON"

1 V or less

78

Power steering 
pressure switch

Engine: warming 
up, idling

When steering wheel is not 
turned

B+

When steering wheel is 
turned

1V or less

81

A/C compressor 
clutch relay

• Engine: idling

• A/C switch: OFF→ ON (A/C compressor is 

operating)

B+

→ 1 V or less 

as A/C clutch 
cycles

83

Ignition switch-ST

Engine: cranking

8 V or more

91

Left bank heated 
oxygen sensor 
(front)

Engine: warming up, 2,500 r/min (check using a 
digital voltmeter)

0 

⇔ 0.8 V 

(changes 
repeatedly) 

92

Right bank heated 
oxygen sensor 
(front)

Engine: warming up, 2,500 r/min (check using a 
digital voltmeter)

0 

⇔ 0.8 V 

(changes 
repeatedly) 

TERMINAL NO. INSPECTION 

ITEM

INSPECTION CONDITION (ENGINE 
CONDITION)

NORMAL 
CONDITION

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1110

93

Engine coolant 
temperature 
sensor

Ignition switch: 
"ON"

When engine coolant 
temperature is 

−20°C (−4°F)

3.9 

− 4.5 V

When engine coolant 
temperature is 0

°C (32°F)

3.2 

− 3.8 V

When engine coolant 
temperature is 20

°C (68°F)

2.3 

− 2.9 V

When engine coolant 
temperature is 40

°C (104°F)

1.3 

− 1.9 V

When engine coolant 
temperature is 60

°C (140°F)

0.7 

− 1.3 V

When engine coolant 
temperature is 80

°C (176°F)

0.3 

− 0.9 V

94

Power supply 
voltage applied to 
throttle position 
sensor

Ignition switch: "ON"

4.9 

− 5.1 V

96

Left bank heated 
oxygen sensor 
(rear)

• Engine: warming up

• Revving

0 and 0.6 

− 1.0 V 

alternates

97

Right bank heated 
oxygen sensor 
(rear)

• Engine: warming up

• Revving

0 and 0.6 

− 1.0 V 

alternates

98

Throttle position 
sensor (sub)

• Remove the 

intake air hose 
at the throttle 
body

• Disconnect the 

throttle position 
sensor 
connector, and 
then connect 
terminal 
numbers No. 3, 
No. 4, No. 5 and 
No. 6 with the 
use of the 
special tool: 
MB991658.

• Ignition switch: 

"ON"

Fully close the throttle valve 
with your finger

2.2 

− 2.8 V

Fully open the throttle valve 
with your finger

4.0 V or more

TERMINAL NO. INSPECTION 

ITEM

INSPECTION CONDITION (ENGINE 
CONDITION)

NORMAL 
CONDITION

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1111

99

Throttle position 
sensor (main)

• Remove the 

intake air hose 
at the throttle 
body

• Disconnect the 

throttle position 
sensor 
connector, and 
then connect 
terminal 
numbers No. 3, 
No. 4, No. 5 and 
No. 6 with the 
use of the 
special tool: 
MB991658.

• Ignition switch: 

"ON"

Fully close the throttle valve 
with your finger

0.3 

− 0.7 V

Fully open the throttle valve 
with your finger

4.0 V or more

102

Manifold absolute 
pressure sensor

Ignition switch: 
"ON"

AT altitude of 0 m (0 ft.)

3.8 

− 4.2 V

AT altitude of 0 m (1,969 ft.) 3.5 

− 3.9 V

AT altitude of 0 m (3,937 ft.) 3.3 

− 3.7 V

AT altitude of 0 m (5,906 ft.) 3.0 

− 3.4 V

Engine: warming up, idling

0.6 

− 1.4 V

When engine is suddenly revved

Voltage Varies

103

Crankshaft 
position sensor

Engine: cranking

0.4 

− 4.0 V *

1

Engine: idling

2.0 

− 3.0 V *

1

104

Camshaft position 
sensor

Engine: cranking

0.4 

− 4.0 V *

1

Engine: idling

2.9 

− 3.9 V *

1

107

Intake air 
temperature 
sensor

Ignition switch: 
"ON"

When Intake air temperature 
is 

−20°C (−4°F)

3.8 

− 4.4 V

When Intake air temperature 
is 0

°C (32°F)

3.2 

− 3.8 V

When Intake air temperature 
is 20

°C (68°F)

2.3 

− 2.9 V

When Intake air temperature 
is 40

°C (104°F)

1.5 

− 2.1 V

When Intake air temperature 
is 60

°C (140°F)

0.8 

− 1.4 V

When Intake air temperature 
is 80

°C (176°F)

0.4 

− 1.0 V

108

Mass airflow 
sensor

Engine: revving

Voltage increase 
in response to 
revving

TERMINAL NO. INSPECTION 

ITEM

INSPECTION CONDITION (ENGINE 
CONDITION)

NORMAL 
CONDITION

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1112

122

Power supply 
voltage applied to 
throttle actuator 
control motor

Ignition switch: "ON"

B+

123

Throttle actuator 
control motor relay

Ignition switch: "ON" 

→ "LOCK(OFF)"

1 V or less 

→ B+ 

→ 1 V or less

125

Left bank heated 
oxygen sensor 
heater (front)

Engine: warming up, idling (15 seconds after 
starting engine)

9 

− 11 V*

1

Engine: revving

9 

− 11 V*

1

 

→ B+ 

(momentarily)

126

Right bank heated 
oxygen sensor 
heater (front)

Engine: warming up, idling (15 seconds after 
starting engine)

9 

− 11 V*

1

Engine: revving

9 

− 11 V*

1

 

→ B+ 

(momentarily)

131

Generator FR 
terminal

• Engine: warming up, idling (radiator fan: 

stopped)

• Headlight: OFF to ON*

2

• Rear defogger switch: OFF to ON

• Stop light switch: OFF to ON

Voltage drops

132

Generator G 
terminal

• Engine: warming up, idling (radiator fan: 

stopped)

• Headlight: OFF to ON*

2

• Rear defogger switch: OFF to ON

• Stop light switch: OFF to ON

Voltage rises 

137

Left bank heated 
oxygen sensor 
heater (rear) 

Engine: warming up, idling

1 V or less

Engine: revving

B+

138

Right bank heated 
oxygen sensor 
heater (rear)

Engine: warming up, idling

1 V or less

Engine: revving

B+

141

Throttle actuator 
control motor (

−)

• Ignition switch: "ON"

• Accelerator pedal: fully closed → fully opened

Decreases 
slightly 
(Approximately. 
2V) from battery 
voltage.

147

Throttle actuator 
control motor (+)

• Ignition switch: "ON"

• Accelerator pedal: fully opened → fully closed

Decreases 
slightly 
(Approximately. 
2V) from battery 
voltage.

TERMINAL NO. INSPECTION 

ITEM

INSPECTION CONDITION (ENGINE 
CONDITION)

NORMAL 
CONDITION