Mitsubishi Evolution X. Manual - part 1090

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CHASSIS ELECTRICAL

54A-721

STEP 12. Check the wiring harness between rear window 
defogger relay connector C-306 (terminal 3) and rear 
window defogger connector F-29 (terminal 1).
NOTE: Also check intermediate connectors C-42 and D-16, 
and joint connector C-102 for loose, corroded, or damaged ter-
minals, or terminals pushed back in the connector. If intermedi-
ate connectors C-42 and D-16, and joint connector C-102 is 
damaged, repair or replace the connector as described in 
GROUP 00E, Harness Connector Inspection 

P.00E-2

.

Q: Is the wiring harness between rear window defogger 

relay connector C-306 (terminal 3) and rear window 
defogger connector F-29 (terminal 1) in good condition?
YES : It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− How to 

Cope with Intermittent Malfunctions 

P.00-15

.

NO :  Repair or replace the wiring harness. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

. Check that the rear window defogger 

system works normally.

STEP 13. Check rear window defogger connector F-03 for 
loose, corroded or damaged terminals, or terminals 
pushed back in the connector.
Q: Is rear window defogger connector F-03 in good 

condition?
YES : Go to Step 14.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the rear window defogger system works normally.

STEP 14. Measure the resistance at rear window defogger 
connector F-03.
(1) Disconnect rear window defogger connector F-03, and 

measure at the wiring harness side.

(2) Measure the resistance between terminal 1 and ground.

• The measured value should be 2 ohms or less.

Q: Does the measured resistance value correspond with 

this range?
YES : Go to Step 16.
NO :  Go to Step 15.

AC709322 BN

Harness side: F-03

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CHASSIS ELECTRICAL

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STEP 15. Check the wiring harness between rear window 
defogger connector F-03 (terminal 1) and the ground.
Q: Is the wiring harness between rear window defogger 

connector F-03 (terminal 1) and the ground in good 
condition?
YES : Check that the rear window defogger system works 

normally.

NO :  Repair or replace the wiring harness. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

. Check that the rear window defogger 

system works normally.

STEP 16. Check A/C-ECU connector C-22 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q: Is A/C-ECU connector C-22 in good condition?

YES : Go to Step 17.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the rear window defogger system works normally.

STEP 17. Check the wiring harness between A/C-ECU 
connector C-22 (terminals 9 and 10) and A/C control panel 
connector C-123 (terminals 1 and 9).
Q: Are the wiring harness between A/C-ECU connector 

C-22 (terminals 9 and 10) and A/C control panel 
connector C-123 (terminals 1 and 9) in good condition?
YES : Go to Step 18.
NO :  Repair or replace the wiring harness. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

. Check that the rear window defogger 

system works normally.

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CHASSIS ELECTRICAL

54A-723

STEP 18. Check the rear window defogger.
(1) Let the engine run at 2,000 r/min, and check the printed 

heater with the battery fully charged.

(2) Turn on the rear window defogger switch, and use a 

voltmeter to measure the voltage in each printed heater at 
middle point A on the rear window glass.

• The value should be approximately 6 volts.

Q: Does the rear window defogger work normally? 

YES : Go to Step 19.
NO :  Repair the rear window defogger.

STEP 19. Replace the A/C control panel and check the 
trouble symptom again
Check the trouble symptom again.
Q: Is the check result satisfactory?

YES : The procedure is complete.
NO :  Replace the A/C-ECU.

REMOVAL AND INSTALLATION

M1540600200171

Refer to GROUP 55 

− Heater control unit 

P.55-119

.

AC407247

Voltage (V)

Normal characteristics of print heater

Abnormal characteristics of print heater

Voltage (V)

AD

12

6

0

12

6

0

(+) terminal

(-) terminal

(+) terminal

(-) terminal

Length of print heater

Length of print heater

A (middle point)

Approximately 6 V

Disconnection 
location

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ON-VEHICLE SERVICE

PRINTED HEATER CHECK

M1540500500175

1. Let the engine run (2,000 r/min), and check the printed 

heater with the battery fully charged.

2. With the rear window defogger switch "ON," use the circuit 

tester to measure the voltage of each printed heater at the 
rear window glass center A point. If approximately 6 V is 
indicated, it is judged good.

3. If the voltage of 12 V is indicated at the A point, there is an 

open circuit between the A point and negative terminal. 
Therefore, by moving the test bar slowly to the negative 
side, search and determine the location where the voltage 
changes suddenly (0 V). The location of voltage change 
indicates the open circuit position.

4. Also, if the voltage indicates 0 V at the A point, there is an 

open circuit between the A point and positive terminal. 
Therefore, search and determine the location of voltage 
change (12 V) using the above mentioned method.

REAR WINDOW DEFOGGER RELAY CHECK

M1540500600246

AC407247

Voltage (V)

Normal characteristics of print heater

Abnormal characteristics of print heater

Voltage (V)

AD

12

6

0

12

6

0

(+) terminal

(-) terminal

(+) terminal

(-) terminal

Length of print heater

Length of print heater

A (middle point)

Approximately 6 V

Disconnection 
location

Battery voltage

Terminal 
number

Normal 
condition

At no energization

3 

− 4

No continuity

With current supply [terminal 1 
(+), terminal 2 (

−)]

Continuity exists 
(2 ohms or less)

AC609147

2

3

4

1

AB

Rear window
defogger relay