Mitsubishi Montero (2002-2004). Manual - part 1139

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-173

CAUTION

Always use the test harness when measuring the voltage 
or resistance value at the female connector. If you fail to do 
so, connectors may be damaged.
(4) Measure the resistance values between joint connector (9) 

D-131 terminal 2 and steering wheel sensor connector D-
225 terminal 3, and between joint connector (9) D-131 
terminal 5 and steering wheel sensor connector D-225 
terminal 4.

• The resistance should measure 2 ohms or less.

CAUTION

If you repair the CAN bus line of the instrument panel wir-
ing harness assembly (the wiring harness connected to 
the steering wheel sensor, the data link connector and the 
resistor) and the transmission wiring harness assembly 
(the wiring harness connected to the G and yaw rate sen-
sor connector and intermediate connector E-123), observe 
the precautions regarding how to repair wiring harness. If 
a new wire is added or a splice point is modified for the 
CAN_L or CAN_H line, an error in the CAN communication 
may be caused.
Q: Does the resistance measure 2 ohms or less?

YES : Diagnose the steering wheel sensor. Refer to 

P.35C-

30

.

NO :  Repair the wiring harness wires between joint 

connector (9) and the steering wheel sensor 
connector.

AC204582

HARNESS SIDE: D-225

AP

HARNESS SIDE: D-131

6

1

9 8

2

7

10

12 11

4

5

3

TEST 
HARNESS

3 2

1

4

5

TEST 
HARNESS

AC204582

HARNESS SIDE: D-225

AQ

HARNESS SIDE: D-131

6

1

9 8

2

7

10

12 11

4

5

3

TEST 
HARNESS

3 2

1

4

5

TEST 
HARNESS

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-174

Diagnostic Item 7:  CAN bus line diagnostics (between the main bus line and the G and yaw rate 
sensor)

CAUTION

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

CAUTION

Before checking CAN bus lines and their inter-
connected components, "ground" yourself, by 
touching a metal object such as an unpainted 
pipe, this will discharge any potentially damag-
ing static that may have built up.

CAUTION

When measuring resistance value or voltage in 
CAN bus lines, use a digital multimeter. If not 
using a digital multimeter, the equipments con-
nected through the CAN bus lines may be dam-
aged.

CAUTION

Disconnect the negative battery terminal when 
measuring the resistance value in the CAN bus 
line. If you fail to do so, the equipments con-
nected through the CAN bus lines may be dam-
aged.

CAUTION

Always use the test harness when measuring the 
voltage or resistance value at the female connec-
tor. If you fail to do so, connectors may be dam-
aged.

CAUTION

If there is a problem in the connector(s) (includ-
ing terminals) or wire(s) of the instrument panel 
wiring harness assembly (the wiring harness 
connected to the steering wheel sensor, the data 
link connector and the resistor) and the trans-
mission wiring harness assembly (the wiring har-
ness connected to the G and yaw rate sensor 
connector and intermediate connector E-123), 
cut and repair the defective wire so that the 
frayed end of the twisted wire should be within 
10 cm (4.0 inches). If it exceeds 10 cm (4.0 

inches), twist the wiring harness just like the 
original twisted wire. If the frayed end exceeds 10 
cm (4.0 inches), a communication error may be 
caused.

CAUTION

If you repair the CAN bus line of the instrument 
panel wiring harness assembly (the wiring har-
ness connected to the steering wheel sensor, the 
data link connector and the resistor) and the 
transmission wiring harness assembly (the wir-
ing harness connected to the G and yaw rate 
sensor connector and intermediate connector E-
123), observe the precautions regarding how to 
repair wiring harness. If a new wire is added or a 
splice point is modified for the CAN_L or CAN_H 
line, an error in the CAN communication may be 
caused.

CAUTION

If there is a problem in the CAN bus line or the 
connectors on the control wiring harness assem-
bly (the wiring harness connected to the M-
ASTC-ECU, the power control module and inter-
mediate 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 connector(s) are repaired, an error 
in the CAN communication may be caused.

AC203824

CONNECTOR

TWISTED WIRE

AB

10 cm
 (4.0 inches)

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-175

This procedure diagnoses the shaded portion below.

AC203825AC

PROBABLE
TROUBLE
SPOT

G AND 
YAW RATE
SENSOR

POWER TRAIN
CONTROL 
MODULE

M-ASTC-ECU

STEERING 
WHEEL 
SENSOR

DATA LINK
CONNECTOR

RESISTOR

CAN Bus Communication Circuit (G and yaw rate sensor)

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-176

.

CIRCUIT OPERATION
The M-ASTC-ECU receives signals through the CAN 
bus line from the G and yaw rate sensor.

.

TECHNICAL DESCRIPTION (COMMENT)
If the M-ASTC-ECU has set DTC code 74, the wiring 
harness between the CAN main bus line and the G 
and yaw rate sensor, the G and yaw rate sensor itself 
or the M-ASTC-ECU may be defective.

.

TROUBLESHOOTING HINTS

• The CAN bus line between the CAN main bus 

line and the G and yaw rate sensor is defective

• Damaged connector(s)

• The G and yaw rate sensor is defective.

• The M-ASTC-ECU is defective.

DIAGNOSIS 

Required Special Tools:

• MB991223: Harness Set

• MB991502: Scan Tool (MUT-II)

AC204176

CONNECTOR: E-123

AT

E-123(GR)

AC204175

CONNECTOR: E-126

AD

E-126(GR)

FLOOR 
CONSOLE