Mitsubishi Evolution X. Manual — part 951

HEADLIGHT

TSB Revision

CHASSIS ELECTRICAL

54A-165

STEP 7. Check wiring harness between headlight
assembly connector, tail light connector or license plate
light connector and ETACS-ECU connector.
Check the ground line for open circuit.

• Check the wiring harness between headlight assembly (LH)

connector A-40 (terminal 4) and ETACS-ECU connector
C-304 (terminal 3). <position light-LH>

• Check the wiring harness between headlight assembly (RH)

connector A-57 (terminal 4) and ETACS-ECU connector
C-304 (terminal 7). <position light-RH>

• Check the wiring harness between tail light (LH) connector

F-24 (terminal 2) and ETACS-ECU connector C-311 (termi-
nal 10). <tail light-LH>
NOTE: Also check intermediate connectors D-17 and F-27
for loose, corroded, or damaged terminals, or terminals
pushed back in the connector. If intermediate connector
D-17 or F-27 is damaged, repair or replace the connector
as described in GROUP 00E, Harness Connector Inspec-
tion

P.00E-2

.

• Check the wiring harness between tail light (RH) connector

F-07 (terminal 2) and ETACS-ECU connector C-311 (termi-
nal 13). <tail light-RH>
NOTE: Also check intermediate connectors D-17 and F-27
and joint connector C-43 for loose, corroded, or damaged
terminals, or terminals pushed back in the connector. If
intermediate connector D-17 or F-27 or joint connector C-43
is damaged, repair or replace the connector as described in
GROUP 00E, Harness Connector Inspection

P.00E-2

.

• Check the wiring harness between license plate light (LH)

connector F-18 (terminal 2) and ETACS-ECU connector
C-311 (terminal 10). <license plate light-LH>
NOTE: Also check intermediate connectors D-17 for loose,
corroded, or damaged terminals, or terminals pushed back
in the connector. If intermediate connector D-17 is dam-
aged, repair or replace the connector as described in
GROUP 00E, Harness Connector Inspection

P.00E-2

.

• Check the wiring harness between license plate light (RH)

connector F-15 (terminal 2) and ETACS-ECU connector
C-311 (terminal 10). <license plate light-RH>
NOTE: Also check intermediate connectors D-17 for loose,
corroded, or damaged terminals, or terminals pushed back
in the connector. If intermediate connector D-17 is dam-
aged, repair or replace the connector as described in
GROUP 00E, Harness Connector Inspection

P.00E-2

.

Q: Is the wiring harness between headlight assembly

connector, tail light connector or license plate light
connector and ETACS-ECU connector in good
condition?
YES : Go to Step 8.
NO : Repair the wiring harness.

HEADLIGHT

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CHASSIS ELECTRICAL

54A-166

STEP 8. Retest the system.
Check that the position light, tail light, or license plate light illu-
minate normally.
Q: Do the position light, tail light, or license plate light

work normally?
YES (The light illuminate normally at both high and low
beams.) : The trouble can be an intermittent malfunction

(Refer to GROUP 00

− How to use

Troubleshooting/inspection Service Points

− How to

Cope with Intermittent Malfunction

P.00-15

).

NO <When the position light does not illuminate> :

Replace the position light socket.

NO <When the license plate light does not illuminate> :

Replace the license plate light socket.

NO <When the tail lights do not illuminate> : Replace the

rear side maker light socket.

Inspection Procedure 10: The auto light function does not work normally.

CAUTION

Whenever the ECU is replaced, ensure that the
power supply circuit, the ground circuit and the
communication circuit are normal.

.

OPERATION

The ETACS-ECU operates this function in accor-
dance with the input signals from driving distance,
lighting control sensor, and column switch (auto light
switch). Also, when the column switch (lighting
switch) is in the "AUTO" position, and when an
abnormality is present to the auto light circuit, the
fail-safe function is activated and the low beam is
turned ON at all times regardless of the brightness
around the vehicle.

.

TECHNICAL DESCRIPTION (COMMENT)

If the auto light function does not work normally, the
above input signal circuit(s) or the ETACS-ECU may
have a problem.

.

TROUBLESHOOTING HINTS

• Malfunction of the lighting control sensor

• Malfunction of the column switch

• Malfunction of the ETACS-ECU

• The wiring harness or connectors may have

loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector

DIAGNOSIS

Required Special Tools:

• MB991958 Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827 M.U.T.-III USB Cable

• MB991910 M.U.T.-III Main Harness A (Vehicles with

CAN communication system)

HEADLIGHT

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CHASSIS ELECTRICAL

54A-167

STEP 1. Using scan tool MB991958, diagnose the CAN bus
line

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the

Scan Tool (M.U.T.-III)

P.54A-105

."

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.
NO : Repair the CAN bus line (Refer to GROUP 54C,

Diagnosis

P.54C-14

).

STEP 2. Using scan tool MB991958, read the diagnostic
trouble code.
Check if DTC is set to the LIN.
Q: Is the DTC set?

YES : Refer to DTC chart

P.54A-107

.

NO : Go to Step 3.

STEP 3. Using scan tool MB991958, read the ETACS
diagnostic trouble code.
Check if DTC is set to the ETACS-ECU.
Q: Is the DTC set?

YES : Troubleshoot the ETACS (Refer to

P.54A-582

).

NO : Go to Step 4.

STEP 4. Check that the headlights operate.
Check that the headlights (low-beam) illuminate normally.
Q: Is the check result normal?

YES : Go to Step 5.
NO : Refer to Inspection Procedure 1 "All the headlights

(low-beam) do not illuminate."

P.54A-128

.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

HEADLIGHT

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CHASSIS ELECTRICAL

54A-168

STEP 5. Using scan tool MB991958, check data list
Use the ETACS-ECU service data to check the signals related
to the operation of auto light function.

• Turn the lighting switch to the "AUTO" position.

Q: Do scan tool MB991958 display the items "Headlight

switch (auto)" as normal condition?
YES : Go to Step 6.
NO : Troubleshoot the ETACS-ECU. Refer to ETACS,

Diagnosis

P.54A-639

.

STEP 6. Lighting control sensor check
Check the lighting control sensor. Refer to

P.54A-191

.

Q: Is the check result normal?

YES : Go to Step 7.
NO : Replace the lighting control sensor.

STEP 7. Retest the system
Check that the auto light function works normally.
Q: Is the check result normal?

YES : The trouble can be an intermittent malfunction (Refer

to GROUP 00

− How to use

Troubleshooting/inspection Service Points, How to
Cope with Intermittent Malfunction

P.00-15

).

NO : Replace the ETACS-ECU.

Inspection Procedure 11: All the turn-signal lights do not illuminate.

.

TECHNICAL DESCRIPTION (COMMENT)

If all the turn-signal lights do not illuminate, the igni-
tion switch (IG1), the turn-signal light switch input cir-
cuit or the ETACS-ECU may have a problem.

.

TROUBLESHOOTING HINTS

• Malfunction of column switch

• Malfunction of the ETACS-ECU

• The wiring harness or connectors may have

loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A (Vehicles with

CAN communication system)

Item No.

Item name

Normal
condition

Item 348

Headlight
switch (auto)

ON