Mitsubishi L200. Manual - part 124

TROUBLESHOOTING

DIESEL FUEL

13A-292

OPERATION

• The electrical current source is supplied from the

engine control relay (terminal No. 3) to the glow
control unit (terminal No. 6). Also, it is supplied
from the glow control unit (terminal No.7) to the
body earth.

• The request signal of operating the glow plug is

input into the glow control unit (terminal No. 1)
from the engine-ECU (terminal No.120).

• The voltage for the glow plug is applied from the

battery to the glow control unit (terminal No. 10).

• The voltage is applied from the glow control unit

(terminal No.1, 2, 3 and 4) to each glow plug.

• The diagnosis signal is output from the glow con-

trol unit (terminal No. 9) to the engine-ECU (ter-
minal No. 126).

FUNCTION

• The voltage applied to the glow control unit (ter-

minal No.10) from the battery is applied to each
glow plug in the duty ratio according to the signal
from the engine ECU.

TROUBLE JUDGMENT

Check Conditions

• While the engine is running

• The electrical continuity duty to the glow plug is

− 83 %.

Judgment Criterion

• The diagnosis signal is not received from the

glow control unit for more than 5 seconds.

PROBABLE CAUSES

• Failed glow control unit

• Open/short circuit or harness damage in glow

control unit power supply/earth circuit or loose
connector contact.

• Loose connector contact; open/short circuit or

harness damage of communication wire between
glow control unit and engine-ECU.

• Failed engine-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Connector check: A-151 glow control
unit connector

Q: Is the check result normal?

YES :

Go to Step 2 .

NO :

Repair or replace the connector.

STEP 2. Perform voltage measurement at A-151
glow control unit connector.

• Disconnect connector, and measure at harness

side.

• Ignition switch: ON

• Voltage between terminal No. 6 and earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 4 .

NO :

Go to Step 3 .

AKB00264

4 3 2 1
8 7 6 5

11 10 9

A-151 (B)

Harness side
connector

Connector: A-151

AKB00264

4 3 2 1
8 7 6 5

11 10 9

A-151 (B)

Harness side
connector

Connector: A-151

TROUBLESHOOTING

DIESEL FUEL

13A-293

STEP 3. Connector check: A-20X engine control
relay connector

Q: Is the check result normal?

YES :

Check and repair harness between A-151

(terminal No. 6) glow control unit connector
and A-20X (terminal No. 3) engine control
relay connector.

• Check power supply line for open/

short circuit.

NO :

Repair or replace the connector.

STEP 4. Perform resistance measurement at A-
151 glow control unit connector.

• Disconnect connector, and measure at harness

side.

• Resistance between terminal No.7 and earth.

Q: Is the check result normal?

YES :

Go to Step 5 .

NO :

Check and repair harness between A-151

(terminal No.7) glow control unit connector
and body earth.

• Check earthing line for open circuit

and damage.

STEP 5. Check harness between A-151 (terminal
No. 1) glow control unit connector and C-103
(terminal No. 120) engine-ECU connector.

• Check signal line for open/short circuit and dam-

age.

Q: Is the check result normal?

YES :

Go to Step 6 .

NO :

Repair the damaged harness wire.

AK501321

3
4

Relay box's side
connector

A-20X

Connector: A-20X

AKB00264

4 3 2 1
8 7 6 5

11 10 9

A-151 (B)

Harness side
connector

Connector: A-151

AKB00264

4 3 2 1
8 7 6 5

11 10 9

A-151 (B)

Harness side
connector

Connector: A-151

AKB00264

4 3 2 1
8 7 6 5

11 10 9

A-151 (B)

Harness side
connector

Connector: A-151

AKA00090

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C-103 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-103

TROUBLESHOOTING

DIESEL FUEL

13A-294

STEP 6. Check harness between A-151 (terminal
No. 9) glow control unit connector and C-103
(terminal No. 126) engine-ECU connector.

• Check signal line for open/short circuit and dam-

age.

Q: Is the check result normal?

YES :

Go to Step 7 .

NO :

Repair the damaged harness wire.

STEP 7. Check harness between A-151 (terminal
No. 6) glow control unit connector and A-20X
(terminal No. 3) engine control relay connector.

• Check power supply line for damage.

Q: Is the check result normal?

YES :

Go to Step 8 .

NO :

Repair the damaged harness wire.

STEP 8. M.U.T.-III diagnosis code.

• Reconfirmation of diagnosis code.

Q: Is the diagnosis code set?

YES :

Go to Step 9 .

NO :

Intermittent malfunction (Refer to GROUP
00

− How to Use Troubleshooting/

Inspection Service points

− How to Cope

with intermittent Malfunctions ).

STEP 9. Replace the glow control unit.

• After replacing the glow control unit, reconfirm

whether the diagnosis code is set.

Q: Is the diagnosis code set?

AKB00264

4 3 2 1
8 7 6 5

11 10 9

A-151 (B)

Harness side
connector

Connector: A-151

AKA00090

101

102

103

104

105

106

107

108

109

110

111

112

113

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149

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153

154

155

156

157

158

117

145

116

144

C-103 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-103

AKB00264

4 3 2 1
8 7 6 5

11 10 9

A-151 (B)

Harness side
connector

Connector: A-151

AK501321

3
4

Relay box's side
connector

A-20X

Connector: A-20X

TROUBLESHOOTING

DIESEL FUEL

13A-295

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,
carry out the forcible DPF regeneration.
(Refer to GROUP 17

− Emission Control −

Diesel Particulate Filter (DPF) System

−

Forcible DPF Regeneration ).

NO :

Check is end.

Code No. P1203: Capacitor Insufficient Charging

FUNCTION

• The engine-ECU monitors the charged state of

the capacitor in the injector drive circuit.

• The engine-ECU checks whether the injector

driving voltage is too low due to insufficient
charging of the capacitor.

TROUBLE JUDGMENT

Check Conditions

• Ignition switch is in "ON" position

• Except during the engine cranking period

• Battery positive voltage is 8 V or more

Judgment Criterion

• A capacitor in low charge state (40 V or less) is

detected in an engine-ECU internal circuit.

PROBABLE CAUSE

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

• After erasing the diagnosis code through M.U.T.-

III, ignition switch is "ON" position and confirm
whether the diagnosis code is output.

Q: Is the diagnosis code set?

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 Malfunctions ).

Code No. P1204: Capacitor Excessive Charging

FUNCTION

• The engine-ECU monitors the charged state of

the capacitor in the injector drive circuit.

• The engine-ECU checks whether the injector

driving voltage is too high due to excessive
charging of the capacitor.

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