Mitsubishi Grandis. Manual - part 519

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54D-174

TROUBLE JUDGMENT

The CAN bus line has been shorted to earth if the 
voltage between the CAN bus line (CAN_L or 
CAN_H) and body earth is less than 1.0 V. In this 
condition, an abnormal voltage may be measured at 
CAN_L and CAN_H lines.

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 a ECU may be 
defective.

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>

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

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54D-175

DIAGNOSTIC PROCEDURE

STEP 1. Connector check: C-112 engine-ECU 
<M/T> or engine-A/T-ECU <A/T> connector, C-02 
combination meter connector and 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: Are the check result normal?

YES : 

Go to Step 2 .

NO : 

Repair the defective connector.

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) Disconnect the engine-ECU <M/T> or 

engine-A/T-ECU <A/T> connector and the 
combination meter connector, and measure at 
the wiring harness side.

CAUTION

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

P.54D-8

.

(2) Ensure that the negative battery terminal is 

AC310615

AS

Harness side

Connector: C-112 <LHD>

C-112 (GR)

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

AC310614

BJ

Connectors: C-02, C-126 
<LHD>

C-02

C-126 (B)

C-126 Harness side

C-02 Harness side

AC310615

AS

Harness side

Connector: C-112 <LHD>

C-112 (GR)

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

AC310614

BJ

Connectors: C-02, C-126 
<LHD>

C-02

C-126 (B)

C-126 Harness side

C-02 Harness side

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54D-176

disconnected.

(3) Resistance between C-126 diagnosis connector 

terminal No.14 and body earth

OK: 1 k

Ω or more

(4) Resistance between C-126 diagnosis connector 

terminal No.6 and body earth

OK: 1 k

Ω or more

Q: Are the check result normal?

YES <all of the measurement results show 1 k

Ω or 

more> : 

Follow diagnostic item 17, Diagnose CAN 

bus lines thoroughly. Refer to 

P.54D-452

.

NO <The resistance between terminal No.14 and 
body earth is less than 1 k

Ω> : 

Go to Step 3 .

NO <The resistance between terminal No.6 and 
body earth is less than 1 k

Ω> : 

Go to Step 28 .

STEP 3. Connector check: C-125 intermediate 
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 4 .

NO : 

Repair the defective connector.

STEP 4. Resistance measurement at the C-125 
intermediate 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) Disconnect the connector, and measure at its 

male-side intermediate connector (at the front 
wiring harness side).

CAUTION

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

P.54D-8

.

(2) Ensure that the negative battery terminal is 

AC209364

AC209364LC

Harness side: C-126
(Front side)

Test 
harness

AC209364

AC209364

AC209364

AC209364

AC209364

AC209364LD

Harness side: C-126
(Front side)

Test 
harness

AC310613

AD

Connector: C-125 <LHD>

AC310613

AD

Connector: C-125 <LHD>

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54D-177

disconnected.

(3) Resistance between C-125 intermediate 

connector terminal No.27 and body earth

OK: 1 k

Ω or more

Q: Is the check result normal?

YES : 

<1 k

Ω or more> Go to Step 5.

NO : 

<less than 1 k

Ω> Go to Step 20.

STEP 5. Connector check: C-09 joint connector 
(CAN2)

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 and its short pins are not 
damaged.

Q: Is the check result normal?

YES : 

Go to Step 6 .

NO : 

Repair a defective connector or replace the 
joint connector.

STEP 6. Resistance measurement at C-09 joint 
connector (CAN2).

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) Disconnect the connector, and measure at the 

wiring harness side.

CAUTION

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

P.54D-8

.

(2) Ensure that the negative battery terminal is 

disconnected.

(3) Resistance between C-09 joint connector (CAN2) 

AC209364LE

Male side: C-125

Test harness

AC310615

AU

Harness side

Connector: C-09 <LHD>

C-09 (GR)

AC209350

1

12

2

13

3

14

4

15

5

16

6

17

7

18

8

19

9

20

10

21

11

22

AB

Short pin

AC310615

AU

Harness side

Connector: C-09 <LHD>

C-09 (GR)

AC209364LG

Harness side: C-09

Test
harness