Mitsubishi Grandis. Manual - part 487

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54D-46

CAN BUS DIAGNOSIS

Diagnostic Item 1: Diagnose the CAN bus lines for short to power supply <LH 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.

DIAGNOSIS

CONTROLLER AREA NETWORK (CAN)

54D-47

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-48

TROUBLE JUDGMENT

Short to power supply may be present when the 
voltage between the CAN bus line (CAN_L or 
CAN_H) and body earth is more than 4.0 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-49

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. Voltage 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.

(2) Connect the negative battery terminal, and turn 

AC310615

AS

Harness side

Connector: C-112 <LHD>

C-112 (GR)

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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)

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AC310614

BJ

Connectors: C-02, C-126 
<LHD>

C-02

C-126 (B)

C-126 Harness side

C-02 Harness side