Mitsubishi L200. Manual — part 179

TROUBLESHOOTING

DIESEL FUEL

13A-512

OPERATION

• When the A/C switch "ON" signal is input to the

engine-ECU, the engine-ECU places the A/C
compressor relay in the "ON" position. Accord-
ingly, the battery voltage supplied to the A/C com-
pressor operates the magnet clutch.

PROBABLE CAUSES

• Failed A/C compressor relay

• Failed A/C compressor assembly

• Damaged harness (Open circuit between A/C

compressor relay and condenser fan relay, A/C
compressor relay and engine-ECU, A/C com-
pressor relay and A/C compressor, and open cir-
cuit between A/C compressor relay and relay
box)

• Damaged connector (A/C compressor relay con-

nector, A/C compressor connector, Engine-ECU
connector)

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

• Refer to Data List Reference Table

P.13A-542

.

a. Item 25: A/C switch
b. Item 26: A/C load signal

c. Item 27: A/C relay

Q: Are the check results normal?

YES :

Go to Step 2.

NO :

Check A/C system (Refer to GROUP 55A

−

Troubleshooting

− Trouble Symptom Chart

<Manual A/C>, GROUP 55B

−

Troubleshooting

− Trouble Symptom Chart

<Automatic A/C>).

STEP 2. Connector check: C-105 engine-ECU
connector

Q: Is the check result normal?

YES :

Go to Step 3.

NO :

Repair or replace.

STEP 3. Check the trouble symptoms.

Q: Does trouble symptom persist?

YES :

Replace the engine-ECU. When the engine-

ECU is replaced, write the chassis number
(Refer to GROUP 00

− Precautions Before

Service

− How to Perform Chassis Number

Writing ). After replacing the engine-ECU,
register the injector identification code and
learn fuel injection (Refer to GROUP 00

−

Precautions Before Service

− What The

Common Rail Engine Learns ). After
registering the injector identification code,
the vehicle equipped with the DPF carries
out the forcible DPF regeneration. (Refer to
GROUP 17

− Emission Control − Diesel

Particulate Filter (DPF) System

− Forcible

DPF Regeneration ).

NO :

Intermittent malfunction (Refer to GROUP
00

− How to Use Troubleshooting/

Inspection Service Points

− How to Cope

with Intermittent Malfunction ).

AKA00089

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C-105 (B)

C-105 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-105

AB

TROUBLESHOOTING

DIESEL FUEL

13A-513

Inspection Procedure 24: Power Steering Fluid Pressure Switch System

OPERATION

• It is detected whether a load is applied on the

power steering fluid pump by steering or not, and
the signal is inputted to the engine-ECU. When
the power steering fluid pressure switch "ON" sig-
nal (a large load on the power steering fluid
pump) is inputted, the engine-ECU provides the
idle-up control.

PROBABLE CAUSES

• Failed power steering fluid pressure switch

• Damaged harness (Open or short circuit between

power steering fluid pressure switch and engine-
ECU)

• Damaged connector (Engine-ECU connector,

power steering fluid pressure switch connector)

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: A-134 power steering
fluid pressure switch connector

Q: Is the check result normal?

AKA00105

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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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127

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8

A-115

A-27

1

Power steering fluid
pressure switch

ON

OFF

B-R

B-R

B-R

Engine-ECU

A-134

(MU801211)

C-103

Power steering fluid pressure switch 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: Grey
R: Red P: Pink V: Violet PU: Purple SI: Silver

AB

AK501383

1

Harness side
connector

Connector: A-134

A-134 (B)

AB

TROUBLESHOOTING

DIESEL FUEL

13A-514

YES :

Go to Step 2 .

NO :

Repair or replace.

STEP 2. Perform voltage measurement at A-134
power steering fluid pressure switch connector.

• Disconnect connector, and measure at harness

side.

• Ignition switch: ON

• Voltage between terminal No. 1 and earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 8 .

NO :

Go to Step 3 .

STEP 3. Perform voltage measurement at C-103
engine-ECU connector.

• Measure engine-ECU terminal voltage.

• Ignition switch: ON

• Voltage between terminal No. 127 and earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 4 .

NO :

Go to Step 5 .

AK501383

1

Harness side
connector

Connector: A-134

A-134 (B)

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

TROUBLESHOOTING

DIESEL FUEL

13A-515

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

Q: Is the check result normal?

YES :

Check intermediate connectors A-27 and A-

115, and repair if necessary. If intermediate
connector are normal, check and repair
harness between A-134 (terminal No. 1)
power steering fluid pressure switch
connector and C-103 (terminal No. 127)
engine-ECU connector.

• Check output line for open circuit.

NO :

Repair or replace.

STEP 5. Connector check: C-103 engine-ECU
connector

Q: Is the check result normal?

YES :

Go to Step 6 .

NO :

Repair or replace the connector.

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

AK501383

1

Harness side
connector

Connector: A-134

A-134 (B)

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