Mitsubishi Galant 9G. Manual — part 1310

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-344

STEP 14. Check the CAN_L and H lines (communication
lines only) between joint connector (3) and the A/C-ECU for
a short circuit. Measure the resistance at joint connector
(3) C-02.

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-10 <manual air conditioning system (low)> or
C-15 <manual air conditioning system (middle) or automatic
air conditioning system>, and measure the resistance at the
wiring harness side of joint connector (3) C-02.

(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.

AC305231AP

CONNECTOR: C-02

AC305234AB

C-10 HARNESS SIDE

C-15 HARNESS SIDE

CONNECTORS: C-10, C-15

C-10 (B)

C-15 (B)

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-345

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

terminals 6 and 17.

OK: 1 k

Ω or more

CAUTION

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

P.54C-5

.

Q: Does the resistance measure 1 k

Ω or more?

YES : If the resistance measures 1 k

Ω or more, go to Step

15 .

NO : If the resistance measures less than 1 k

Ω, repair the

wiring harness between joint connector (3) and the
A/C-ECU connector.

STEP 15. Check the A/C-ECU for short circuit. Measure the
resistance at A/C-ECU connector C-10 <manual air
conditioning system (low)> or C-15 <manual air
conditioning system (middle) or automatic air conditioning
system>.

CAUTION

A digital multimeter should be used. For details refer to

P.54C-4

.

(1) Disconnect A/C-ECU connector C-10 <manual air

conditioning system (low)> or C-15 <manual air
conditioning system (middle) or automatic air conditioning
system>, and measure the resistance at the component
side of A/C-ECU connector C-10 <manual air conditioning
system (low)> or C-15 <manual air conditioning system
(middle) or automatic air conditioning system>.

AC209438

AC209438

TEST
HARNESS

AS

TEST
HARNESS

1110 9 8 7 6 5 4 3 2 1

22 21201918 1716 15 14 1312

HARNESS SIDE: C-02

AC305234AB

C-10 HARNESS SIDE

C-15 HARNESS SIDE

CONNECTORS: C-10, C-15

C-10 (B)

C-15 (B)

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-346

(2) Measure the resistance between A/C-ECU connector

terminals 5 and 6 <manual air conditioning system (low)> or
terminals 14 and 15 <manual air conditioning system
(middle) or automatic air conditioning system>.

OK: 1 k

Ω or more

Q: Does the resistance measure 1 k

Ω or more?

YES : If the resistance measures 1 k

Ω or more, diagnose

CAN bus lines thoroughly by referring to

P.54C-486

.

NO : If the resistance measures less than 1 k

Ω, replace the

A/C-ECU.

AC209438

AC209438

COMPONENT SIDE: C-10

AT

TEST
HARNESS

AC209438

AC209438

COMPONENT SIDE: C-15

AY

TEST
HARNESS

TEST
HARNESS

DIAGNOSIS

TSB Revision

CONTROLLER AREA NETWORK (CAN)

54C-347

STEP 16. Check the CAN_L and H lines (communication
lines including the SRS-ECU) between joint connector (3)
and the SRS-ECU for a short circuit. Measure the
resistance at joint connector (3) C-02.

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 measure the

resistance at the wiring harness side of joint connector (3)
C-02.

(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.

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

terminals 3 and 14.

OK: 1 k

Ω or more

Q: Does the resistance measure 1 k

Ω or more?

YES : If the resistance measures 1 k

Ω or more, go to Step

23 .

NO : If the resistance measures less than 1 k

Ω, go to Step

17.

STEP 17. Check intermediate connector C-22 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: Is intermediate connector C-22 in good condition?

YES : Go to Step 18.
NO : Repair the damaged parts.

AC305231AP

CONNECTOR: C-02

AC209438

11

22

10

21

9

20

8

19

7

18

6

17

5

16

4

15

3

14

2

13

1

12

TEST
HARNESS

AV

TEST
HARNESS

HARNESS SIDE: C-02

AC305233 AI

CONNECTOR: C-22

C-22 (Y)