Mitsubishi Grandis. Manual — part 601

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54D-502

Diagnostic Item 19: Diagnose CAN bus lines thoroughly <RH drive vehicles without ASC>

CAUTION

When servicing a CAN bus line, earth yourself by
touching a metal object such as an unpainted
water pipe. If you fail to do, a component
connected to the CAN bus line may be broken.

A/C-ECU

CENTER DISPLAY

COMBINATION
METER

DIAGNOSIS
CONNECTOR

ABS-ECU

ENGINE-ECU<M/T>
ENGINE·A/T-ECU<A/T>

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Gray R : Red P : Pink V : Violet

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54D-503

TROUBLE JUDGMENT

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

COMMENTS ON TROUBLE SYMPTOM

The CAN bus line wire or connectors may have
loose, corroded, or damage terminals, or terminals
pushed back in the connector.

POSSIBLE CAUSES

• Damaged harness wires and connectors

• Malfunction of the ETACS-ECU

• Malfunction of the combination meter

• Malfunction of the A/C-ECU

• Malfunction of the SRS-ECU

• Malfunction of the multi-centre display

• Malfunction of the ABS-ECU

• Malfunction of the engine-ECU <M/T> or

engine-A/T-ECU <A/T>

DIAGNOSTIC PROCEDURE

STEP 1. Connector check: C-126 diagnosis
connector

CAUTION

The strand end of the twist wire should be within
10 cm from the connector. For details refer to

P.54D-8

.

Q: Is the check result normal?

YES :

Go to Step 2 .

NO :

Repair the defective connector.

ETACS-ECU

SRS-ECU

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Gray R : Red P : Pink V : Violet

AC310631AK

Connector: C-126 <RHD>

C-126 (B)

Harness side
(Front side)

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54D-504

STEP 2. Resistance measurement at the C-126
diagnosis connector.

CAUTION

A digital multimeter should be used. For details
refer to

P.54D-8

.

CAUTION

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

P.54D-8

.

(1) Measure at the diagnosis connector wiring

harness side.

(2) Ignition switch: OFF (LOCK)

CAUTION

When measuring the resistance, disconnect the
negative battery terminal. For details refer to

P.54D-8

.

(3) Ensure that the negative battery terminal is

disconnected.

(4) Continuity between C-126 diagnosis connector

terminal Nos. 6 and 14

Q: How much resistance is measured?

2

Ω or less :

Diagnose the lines between the

CAN_L and H for short circuit. Refer to

P.54D-354

.

No continuity :

Diagnose the terminator resistors

at both ends. Refer to

P.54D-419

.

More than 2

Ω (i.e. continuity exists) :

Go to Step 3

.

STEP 3. Connector check: A-07 joint connector
(CAN1)
NOTE: When checking A-07 joint connector (CAN1),
disassemble and check the engine compartment
relay box by referring to

P.54D-616

.

CAUTION

The strand end of the twist wire should be within
10 cm from the connector. For details refer to

P.54D-8

.

When checking the joint connector, ensure that its
wiring harness side is not damaged.

Q: Is the check result normal?

YES :

Go to Step 4 .

NO :

Repair a defective connector or replace the
joint connector (front wiring harness
assembly).

STEP 4. MUT-III CAN bus diagnostics [A-07 joint
connector (CAN1) disconnected]

(1) Disconnect the joint connector (CAN1), and

AC310631AK

Connector: C-126 <RHD>

C-126 (B)

Harness side
(Front side)

AC311938 CC

Front side : C-126

Test
harness

Test
harness

AC302572AD

Connector: A-07

Harness side

AC302572AD

Connector: A-07

Harness side

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54D-505

check by using the MUT-III.

(2) Check that the MUT-III indications correspond to

the illustration.

Q: Is the check result normal?

YES :

<MUT-III indications correspond to the

illustration> Go to Step 22 .

NO :

<MUT-III indications do not correspond to
the illustration> Go to Step 5 .

STEP 5. Connector check: C-09 joint connector
(CAN2) and C-02 combination meter connector

CAUTION

The strand end of the twist wire should be within
10 cm from the connector. For details refer to

P.54D-8

.

When checking the joint connector, ensure that its
wiring harness side is not damaged.

Q: Is the check result normal?

YES :

Go to Step 6 .

NO :

Repair a defective connector or replace the
joint connector.

AC309836

MUT

J/C (2)

METER

ETAC S

J/C (1)

ABS-ECU

ENG/AT-ECU

A/C -ECU

C. DISPL AY

SRS-ECU

AC

: Red section

on screen

AC310631AX

Connector: C-02 <RHD>

Harness side

C-02

AC310628AY

Connector: C-09 <RHD>

C-09 (GR)

Harness side

AC209350

1

12

2

13

3

14

4

15

5

16

6

17

7

18

8

19

9

20

10

21

11

22

AC

Short pin