Mitsubishi L200. Manual - part 69

TROUBLESHOOTING

DIESEL FUEL

13A-72

STEP 11. Check harness between A-135 (terminal 
No. 3) air flow sensor connector and C-103 
(terminal No. 140) engine-ECU connector.

• Check output line for short circuit.

Q: Is the check result normal?

YES : 

Replace the air flow sensor.

NO : 

Repair the damaged harness wire.

STEP 12. Perform voltage measurement at C-103 
engine-ECU connector.

• Measure engine-ECU terminal voltage.

• Disconnect A-135 air flow sensor connector.

• Ignition switch: ON

• Voltage between terminal No. 140 and earth.

OK: 4.9 

− 5.1 V

Q: Is the check result normal?

YES : 

Go to Step 14 .

NO : 

Go to Step 13 .

AKA00399

AB

Harness side 
connector

A-135 (B)

Connector: A-135

AKA00090

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144

C-103 (B)

C-103 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-103

AB

AKA00090

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C-103 (B)

C-103 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-103

AB

AKA00399

AB

Harness side 
connector

A-135 (B)

Connector: A-135

TROUBLESHOOTING

DIESEL FUEL

13A-73

STEP 13. Connector check: C-103 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Check and repair harness between A-135 

(terminal No. 3) air-flow sensor connector 
and C-103 (terminal No. 140) engine-ECU 
connector.

• Check output line for open circuit.

NO : 

Repair or replace the connector.

STEP 14. Connector check: C-103 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Repair or replace the connector.

AKA00090

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144

C-103 (B)

C-103 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-103

AB

AKA00399

AB

Harness side 
connector

A-135 (B)

Connector: A-135

AKA00090

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C-103 (B)

C-103 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-103

AB

TROUBLESHOOTING

DIESEL FUEL

13A-74

Code No. P0103: Air Flow Sensor Circuit High Input

OPERATION

• Power is supplied by the engine control relay (ter-

minal No. 3) to the air flow sensor (terminal No. 
5), and the air flow sensor (terminal No. 4) is 
earthed through the engine-ECU (terminal No. 
155).

• The air flow sensor (terminal No. 3) outputs a 

sensor signal, which is input into the engine-ECU 
(terminal No. 140).

AKA00355

1

2

3
4

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103104 105 106107 108109 110 111112 113 114115

118119 120 121122 123124 125126127 128 129130

131132 133 134135 136137 138139140 141142 143

146147 148 149150 151152 153154155 156 157158

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101 102

103104 105 106107 108109 110 111112 113 114115

118119 120 121122 123124 125126127 128 129130

131132 133 134135 136137 138139140 141142 143

146147 148 149150 151152 153154155 156 157158

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5

4

3

2

1

W-R

W-B

W-B

W-B

Fusible link

BR-B

W-R

R

A-20X

Engine

control

relay

Relay

box

Air flow sensor

Engine-ECU

140

3

155

5

4

1

3

A-115

4

3

2

Air Flow Sensor Circuit

C-103

A-135

AB

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

To engine-ECU

OFF

ON

5 V

10

23

20A

Heat
sensitizing
resistance

TROUBLESHOOTING

DIESEL FUEL

13A-75

FUNCTION

• The air flow sensor outputs pulse signal that var-

ies in accordance with the intake air volume.

• In response to the signal, the engine-ECU con-

trols EGR control, etc.

TROUBLE JUDGMENT

Check Conditions

• Battery positive voltage is 8 − 16 V

• 2 seconds later after the ignition switch has been 

in "ON" position or the engine has started up.

Judgment Criterion

• The air flow sensor output voltage is 4.72 V or 

more.

PROBABLE CAUSES

• Failed air flow sensor

• Open circuit in air flow sensor circuit or loose 

connector contact

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list 

• Refer to Data List Reference Table 

P.13A-542

.

a. Item 114: Air flow sensor

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Use Troubleshooting/

Inspection Service Points 

− How to Cope 

with Intermittent Malfunctions ).

NO : 

Go to Step 2 .

STEP 2. Connector check: A-135 air flow sensor 
connector

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Repair or replace the connector.

STEP 3. Perform resistance measurement at A-
135 air flow sensor connector.

• Disconnect connector, and measure at harness 

side.

• Resistance between terminal No. 4 and earth.

OK: Continuity (2 

Ω or less)

Q: Is the check result normal?

YES : 

Go to Step 7 .

NO : 

Go to Step 4 .

STEP 4. Connector check: C-103 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Repair or replace the connector.

AKA00399

AB

Harness side 
connector

A-135 (B)

Connector: A-135

AKA00399

AB

Harness side 
connector

A-135 (B)

Connector: A-135

AKA00090

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C-103 (B)

C-103 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-103

AB