Mitsubishi Evolution X. Manual - part 995

RADIO AND CD PLAYER

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CHASSIS ELECTRICAL

54A-341

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COMMENTS ON TROUBLE SYMPTOM

When the audio does not operate normally by operating the 
audio control unit of the center panel unit, the radio and CD 
player, center panel unit, or the power supply circuit system of 
center panel unit may be faulty.

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PROBABLE CAUSES

• The radio and CD player may be defective.

• The center panel unit may be defective.

• Damaged harness wires and connectors

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB992006: Extra Fine Probe

STEP 1. Check center panel unit connector C-124 and 
radio and CD player connector C-109 for loose, corroded 
or damaged terminals, or terminals pushed back in the 
connector.
Q: Are center panel unit connector C-124 and radio and CD 

player connector C-109 in good condition?
YES : Go to Step 2.
NO :  Repair or replace the damaged component(s) (Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

).

STEP 2. Check the wiring harness between center panel 
unit connector C-124 (terminal 1, 2) and radio and CD 
player connector C-109 (terminal 8, 18).

• Check the communication lines for open circuit and short 

circuit.

Q: Is the wiring harness between center panel unit 

connector C-124 (terminal 1, 2) and radio and CD player 
connector C-109 (terminal 8, 18) in good condition?
YES : Go to Step 3.
NO :  The wiring harness may be damaged or the 

connector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the connector. 
Repair the wiring harness as necessary.

AC708951BF

C-109

C-124

Connectors: C-109, C-124

AC708972BA

Connectors: C-307, C-317

ETACS-ECU

C-307 (B)

C-317

RADIO AND CD PLAYER

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CHASSIS ELECTRICAL

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STEP 3. Check the ground circuit to the center panel unit. 
Measure the resistance at center panel unit connector 
C-124.
(1) Disconnect the connector, and measure at the wiring 

harness side.

(2) Measure resistance between terminal 9 and ground.

OK: The resistance should be 2 ohm or less.

Q: Is the measured resistance 2 ohms or less?

YES : Go to Step 5.
NO :  Go to Step 4.

STEP 4. Check the wiring harness between center panel 
unit connector C-124 (terminal 9) and ground.

• Check the ground wires for open circuit.

Q: Is the wiring harness between center panel unit 

connector C-124 (terminal 9) and ground in good 
condition?
YES : Check the trouble symptom.
NO :  The wiring harness may be damaged or the 

connector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the connector. 
Repair the wiring harness as necessary.

STEP 5. Check the power supply circuit to the center panel 
unit. Measure the voltage at center panel unit connector 
C-124.
(1) Disconnect the connector, and measure at the harness side 

connector.

(2) Measure voltage between terminal 7 and ground.

OK: Battery voltage

Q: Is the measured voltage battery voltage?

YES : Go to Step 7.
NO :  Go to Step 6.

AC709322 AX

Harness side: C-124

AC709325 AI

Harness side: C-124

RADIO AND CD PLAYER

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CHASSIS ELECTRICAL

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STEP 6. Check the wiring harness between center panel 
unit connector C-124 (terminal 7) and fusible link 34.

• Check the power supply line for open circuit and short cir-

cuit.

NOTE: Also ETACS-ECU connector C-307, C-317 for loose, 
corroded, or damaged terminals, or terminals pushed back in 
the connector. If joint connector ETACS-ECU connector C-307, 
C-317 are damaged, repair or replace the connector as 
described in GROUP 00E, Harness Connector Inspection 

P.00E-2

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Q: Is the wiring harness between center panel unit 

connector C-124 (terminal 7) and fusible link 34 in good 
condition?
YES : Check the trouble symptom.
NO :  The wiring harness may be damaged or the 

connector(s) may have loose, corroded or damaged 
terminals, or terminals pushed back in the connector. 
Repair the wiring harness as necessary.

STEP 7. Replace the center panel unit temporarily, and 
check the trouble symptom.
Replace the center panel unit temporarily, and check that the 
audio works normally.
Q: Is the check result normal?

YES : Replace the center panel unit.
NO :  Replace the radio and CD player.

RADIO AND CD PLAYER

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CHASSIS ELECTRICAL

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Inspection Procedure 5: Audio illuminations does not work normally.

CAUTION

Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communi-
cation circuit are normal.

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Center Panel Unit Communication Circuit

CENTER PANEL
UNIT

AUDIO SWITCH PANEL

LCD PANEL (AUDIO)

A/C 
CONTROL 
PANEL

JOINT
CONNECTOR (3)

COMBINATION METER

RADIO AND CD
PLAYER

AC708950

Connectors: C-04, C-101

BK

C-04

C-101 (B)

AC708951BH

C-109

C-124

Connectors: C-109, C-123, C-124

C-123