Mitsubishi Grandis. Manual - part 696

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-35

STEP 13. Perform voltage measurement at B-106 
air flow sensor connector.

• Use special tool test harness (MB991709) to 

connect only terminal No. 1 and No. 4, and then 
measure at pick-up harness.

• Ignition switch: ON 

• Voltage between terminal No. 1 and earth.

OK:

Ambient temperature at 

−20°C: 3.8 − 4.4 V

Ambient temperature at 0

°C: 3.2 − 3.8 V

Ambient temperature at 20

°C: 2.3 − 2.9 V 

Ambient temperature at 40

°C: 1.5 − 2.1 V 

Ambient temperature at 60

°C: 0.8 − 1.4 V

Ambient temperature at 80

°C: 0.4 − 1.0 V 

Q: Is the check result normal?

YES : 

Go to Step 7 .

NO : 

Go to Step 14 .

STEP 14. Connector check: C-113 engine-ECU 
<M/T> connector or engine-A/T-ECU <A/T> 
connector

Q: Is the check result normal?

YES : 

Go to Step 15 .

NO : 

Repair or replace.

AK300969

2

1

3

4

Harness side connector

AC

Connector: B-106

B-106 (GR)

AK305616AB

Connector: C-113

<L.H. drive vehicles>

<R.H. drive vehicles>

C-113 (GR)

C-113 (GR)

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

Harness side connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-36

STEP 15. Check harness between B-106 (terminal 
No. 1) air flow sensor connector and C-113 
(terminal No. 99) engine-ECU <M/T> connector or 
engine-A/T-ECU <A/T> connector.

• Check output line for damage.

Q: Is the check result normal? 

YES : 

Go to Step 7 .

NO : 

Repair.

AK300969

2

1

3

4

Harness side connector

AC

Connector: B-106

B-106 (GR)

AK305616AB

Connector: C-113

<L.H. drive vehicles>

<R.H. drive vehicles>

C-113 (GR)

C-113 (GR)

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

Harness side connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-37

Code No. P0115: Engine Coolant Temperature Sensor System

OPERATION

• A power voltage of 5 V is applied to the engine 

coolant temperature sensor output terminal 
(terminal No. 1) from the engine-ECU <M/T> or 
engine-A/T-ECU <A/T> (terminal No. 98).

• The power voltage is earthed to the engine-ECU 

<M/T> or engine-A/T-ECU <A/T> (terminal No. 
96) from the engine coolant temperature sensor 
(terminal No. 2).

FUNCTION

• The engine coolant temperature sensor converts 

the engine coolant temperature into a voltage 
signal, and inputs the voltage to the engine-ECU 
<M/T> or engine-A/T-ECU <A/T>.

• In response to the signal, the engine-ECU <M/T> 

or engine-A/T-ECU <A/T> controls the fuel 
infection amount and the fast idle speed when the 
engine is cold state.

• The engine coolant temperature sensor is a kind 

of resistor, which has characteristics to reduce its 
resistance as the engine coolant temperature 
rises. Therefore, the sensor output voltage varies 
with the engine coolant temperature, and 
becomes lower as the engine coolant 
temperature rises.

TROUBLE JUDGMENT

Check Condition

• 2 seconds later after the ignition switch has been 

in ON position or just after the engine has started 
up.

Judgment Criteria

• The sensor output voltage is 4.6V or more (water 

temperature of below 

−45°C or equivalent) for 4 

seconds.

Or

• The sensor output voltage is 0.1V or less (water 

temperature of above 140

°C or equivalent) for 4 

seconds.

AK305549

9192

939495

96979899

100

105

113114

115116117

118119120

106

107108109

110111112

101102103

104

1 2

1 2

BR

J/C (4)
c-116

Y-V

BR

Engine-ECU <M/T> or
engine-A/T-ECU <A/T>

Engine coolant
temperature sensor

B-08

(MU802406)

C-113

(MU803805)

Engine coolant temperature sensor circuit

Wire colour code
B: Black  LG: Light green  G: Green  L: Blue  W: White  Y: Yellow  SB: Sky blue  BR: Brown  O: Orange  GR: Gray
R: Red  P: Pink  V: Violet

2

28

33

96

1

98

AB

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-38

Check Conditions

• After the engine has started up.

Judgment Criteria

• The sensor output voltage rises 1.6V or more 

(engine coolant temperature below 40

°C or 

equivalent) from 1.6V or less (engine coolant 
temperature above 40

°C or equivalent).

PROBABLE CAUSE

• Failed engine coolant temperature sensor

• Open/short circuit in engine coolant temperature 

sensor circuit or loose connector contact

• Failed engine-ECU <M/T>

• Failed engine-A/T-ECU <A/T>

DIAGNOSIS PROCEDURE

STEP 1. MUT-III data list

• Item 21: Engine coolant temperature sensor

OK:

Engine cold state: At ambient temperature 

(atmospheric temperature) or equivalent.

Engine hot state: At 80 

− 120°C

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

NO : 

Go to Step 2 .

STEP 2. Connector check: B-08 engine coolant 
temperature sensor connector

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Repair or replace.

STEP 3. Perform resistance measurement at B-08 
engine coolant temperature sensor connector.

• Disconnect connector, and measure at sensor 

side.

• Resistance between terminal No. 1 and No. 2.

OK:

Engine coolant temperature at 

−20°C: 14 − 17 

k

Ω

Engine coolant temperature at 0

°C: 5.1 − 6.5 

k

Ω

Engine coolant temperature at 20

°C: 2.1 − 2.7 

k

Ω

Engine coolant temperature at 40

°C: 0.9 − 1.3 

k

Ω

Engine coolant temperature at 60

°C: 0.48 − 

0.68 k

Ω

Engine coolant temperature at 80

°C: 0.26 − 

0.36 k

Ω

Q: Is the check result normal?

YES : 

Go to Step 4 .

NO : 

Replace engine coolant temperature 
sensor.

STEP 4. Perform resistance measurement at B-08 
engine coolant temperature sensor connector.

• Disconnect connector and measure at harness 

side.

• Voltage between terminal No. 2 and earth.

OK: 2 

Ω or less

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Go to Step 5 .

AK300971

1

2

AC

Harness side connector

B-08 (B)

Connector: B-08

AK300971

1

2

AC

Harness side connector

B-08 (B)

Connector: B-08

AK300971

1

2

AC

Harness side connector

B-08 (B)

Connector: B-08