Mitsubishi Montero (2004+). Manual - part 1115

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-171

Diagnostic Item 5: CAN bus line diagnostics (between the main bus line and the power control 
module)

CAUTION

Prior to this diagnosis procedure, diagnose the CAN main bus line.

CAUTION

If there is a problem in the CAN bus line or the connectors on the control wiring harness assembly 
(the wiring harness connected to the M-ASTC-ECU, the power control module and intermediate con-
nector E-123), do not attempt to repair the wiring harness or connector(s), but replace the wiring har-
ness assembly. If a wire is added or the connector(s) are repaired, an error in the CAN communication 
may be caused.
This procedure diagnoses the shaded portion below.

AC204175

CONNECTOR: E-126

HARNESS SIDE

E-126(GR)

E-126(GR)

AB

FLOOR 
CONSOLE

1

2

4 3

AC203825AE

PROBABLE
TROUBLE
SPOT

G AND 
YAW RATE
SENSOR

POWER TRAIN
CONTROL 
MODULE

M-ASTC-ECU

STEERING 
WHEEL 
SENSOR

DATA LINK
CONNECTOR

RESISTOR

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-172

.

CIRCUIT OPERATION
The M-ASTC-ECU receives signals through the CAN 
bus line from the power control module.

.

TECHNICAL DESCRIPTION (COMMENT)
If the M-ASTC-ECU has set DTC code 35 or 36, the 
wiring harness between the CAN main bus line and 
the power control module, the power control module 
or the M-ASTC-ECU may be defective.

.

TROUBLESHOOTING HINTS

• The CAN bus line between the CAN main bus 

line and the power control module is defective.

• Damaged connector(s)

• The power control module is defective

• The M-ASTC-ECU is defective.

DIAGNOSIS 

Required Special Tools:

•  MB991958: Scan Tool (MUT-III Sub Assembly)

CAN Bus Communication Circuit (powertrain control module)

AC204171

CONNECTOR: D-134

AK

D-134(GR)

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-173

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

• MB991223: Harness Set

STEP 1. Using scan tool MB991958, read the MFI 
diagnostic trouble code.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the MFI DTC is set.
(4) Turn the ignition switch to the "LOCK (OFF)" position.
Q: Are MFI DTCs set?

YES : Diagnose the power control module. Refer to 

P.13A-26

.

NO :  Go to Step 2.

AC307591 AC

MB991911

MB991824

MB991827

AC307591

DATA LINK

CONNECTOR

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-174

STEP 2. Check power control module connector D-134.

CAUTION

If there is a problem in the CAN bus line or the connectors 
on the control wiring harness assembly (the wiring har-
ness connected to the M-ASTC-ECU, the power control 
module and intermediate connector E-123), do not attempt 
to repair the wiring harness or connector(s), but replace 
the wiring harness assembly. If a wire is added or the con-
nector(s) are repaired, an error in the CAN communication 
may be caused.
Q: Is power control module connector D-134 in good 

condition?
YES : Go to Step 3.
NO :  Replace the control wiring harness assembly.

STEP 3. Check the wiring harness between power control 
module connector D-134 and the CAN main bus line.

AC204171

CONNECTOR: D-134

HARNESS SIDE

D-134(GR)

D-134(GR)

AE

80

87

73

66

67

65
74

81

75

82

6261

72

68

69

70

71

78

85

77

8483

76

79

86

63

64

8988

AC203824

CONNECTOR

TWISTED WIRE

AB

10 cm
 (4.0 inches)

AC204171

CONNECTOR: D-134

HARNESS SIDE

D-134(GR)

D-134(GR)

AE

80

87

73

66

67

65
74

81

75

82

6261

72

68

69

70

71

78

85

77

8483

76

79

86

63

64

8988