Mitsubishi 380. Manual - part 746

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-395

STEP 2. Check the CAN bus lines between joint connector 
(3) and the A/C-ECU. Measure the resistance between joint 
connector (3) C-02 and A/C-ECU connector C-15 automatic 
air conditioning system.

CAUTION

A digital multimeter should be used. For details refer to 

P.54C-4

.

CAUTION

The test wiring harness should be used. For details refer to 

P.54C-4

.

(1) Disconnect joint connector (3) C-02 and A/C-ECU 

connector C-15 automatic air conditioning system, and 
measure the resistances at the wiring harness sides of joint 
connector (3) C-02 and A/C-ECU connector C-15 automatic 
air conditioning system>.

(2) Turn the ignition switch to the "LOCK" (OFF) position.

CAUTION

Disconnect the negative battery terminal. For details refer 
to 

P.54C-4

.

(3) Disconnect the negative battery terminal.

16DB408A

CONNECTOR: C-02

16DB477A

C-15 HARNESS SIDE

CONNECTOR:  C-15

C-15 (B)

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-396

(4) Measure the resistance between joint connector (3) 

terminal 17 and A/C-ECU connector C-15 terminal 14 
automatic air conditioning system.

OK: 2 ohms or less

(5) Measure the resistance between joint connector (3) 

terminal 6 and A/C-ECU connector C-15 terminal 15 
automatic air conditioning system>.

OK: 2 ohms or less

CAUTION

Strictly observe the specified wiring harness repair proce-
dure. For details refer to 

P.54C-5

.

Q: Do all the resistances measure 2 ohms or less?

YES : If all the resistances measure 2 ohms or less, power 

supply to the A/C-ECU may be suspected. Diagnose 
the air conditioning system. Refer to GROUP 55, 
Auto-A/C diagnosis 

P.55-5

.

NO :  If either of the resistances measures more than 2 

ohms or all the resistances measure more than 2 
ohms, repair the wiring harness between joint 
connector (3) and the A/C-ECU connector. 

AC204582

AC204582

HARNESS SIDE: C-02

TEST HARNESS

CG

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TEST 
HARNESS

HARNESS SIDE: C-15

AC204582

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20191817161514131211

TEST 
HARNESS

CI

HARNESS SIDE: C-15

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TEST HARNESS

HARNESS SIDE: C-02

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-397

DIAGNOSTIC ITEM 15: Diagnose the lines between CAN main bus line and the SRS-ECU.

CAUTION

When servicing a CAN bus line, ground yourself 
by touching a metal object such as an unpainted 
water pipe. If you fail to do so, a component con-
nected to the CAN bus line may be damaged.

.

TROUBLE JUDGMENT

If the MUT-III cannot received signals from the 
SRS-ECU, CAN bus line connector(s) are broken or 
an open circuit has occurred.

.

COMMENTS ON TROUBLE SYMPTOM

The wiring harness wire or connectors may have 
loose, corroded, or damage terminals, or terminals 
pushed back in the connector, or the SRS-ECU may 
be defective.

.

TROUBLESHOOTING HINTS

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

• The wiring harness or connectors may have 

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

• The SRS-ECU may be defective

16DB408A

CONNECTOR: C-02

16DB478A

CONNECTOR: C-121

HARNESS SIDE

C-121 (Y)

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DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54C-398

DIAGNOSIS

Required Special Tool:

• MB991223: Harness Set

STEP 1. Check joint connector C-02 and SRS-ECU 
connector C-121 for loose, corroded or damaged 
terminals, or terminals pushed back in the connector.

CAUTION

The strand end of the twisted wire should be within 10 cm 
(4 inches) from the connector. For details refer to 

P.54C-4

.

Q: Are joint connector C-02 and SRS-ECU connector C-121 

in good condition?
YES : Go to Step 2.
NO :  Repair the damaged parts. Replace the joint 

connector as necessary.

16DB478A

CONNECTOR: C-121

HARNESS SIDE

C-121 (Y)

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16DB408A

CONNECTOR: C-02