Mitsubishi Montero (2002-2004). Manual — part 1102

M-ASTC DIAGNOSIS

TSB Revision

MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-25

.

CIRCUIT OPERATION
The M-ASTC-ECU gathers information regarding lat-
eral and longitudinal gravities and yaw rate, through
the CAN bus line from the G and yaw rate sensor.

.

M-ASTC DTC SET CONDITION
DTC 62, 63, 64, 65, 71, 72, 73, 76 or 77 is set if the
M-ASTC-ECU detects any trouble in the G and yaw
rate sensor system. In this case, the G and yaw rate
sensor is sending data to the ECU, but the data con-
tains a fault.

.

TROUBLESHOOTING HINTS
The most likely causes for DTC 74 to set are:

• The G and yaw rate sensor is defective.

• Damaged harness wires and connectors

• The M-ASTC-ECU is defective.

DIAGNOSIS

Required Special Tools:

• MB991223: Harness Set

• MB991502: Scan Tool (MUT-II)

STEP 1. Using scan tool MB991502, check data list items
27, 28 and 29.
(1) Confirm that the vehicle is not canted to one side or corner.

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991502.
(2) Connect scan tool MB991502 to the data link connector

(16-pin).

(3) Turn the ignition switch to the "ON" position.
(4) Check that the G and yaw rate sensor output signal is

approximately 0 m/s

2

.

(5) Remove the G and yaw rate sensor with the wire and

connector attached.

(6) When the G and yaw rate sensor is inclined, the readings

on data list items 27, 28 and 29 should change.

Q: When the G and yaw rate sensor is inclined, do the

readings on data list items 27, 28 and 29 change?
YES : Go to Step 8.
NO : Go to Step 2.

AC204176

CONNECTOR: E-111

AK

AC204175

CONNECTOR: E-126

AD

E-126(GR)

FLOOR
CONSOLE

M-ASTC DIAGNOSIS

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MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-26

STEP 2. Check the power supply system from the ignition
switch (IG1) to the G and yaw rate sensor. Measure at G
and yaw rate sensor connector E-126.
(1) Disconnect G and yaw rate sensor connector E-126, and

measure the voltage at the harness-side connector.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between G and yaw rate sensor

connector E-126 terminal 1 and body ground.

• The voltage should measure battery voltage (approxi-

mately 12 volts).

Q: Does the voltage measure battery voltage

(approximately 12 volts)?
YES : Go to Step 5.
NO : Go to Step 3.

STEP 3. Check G and yaw rate sensor connector E-126.
Q: Is G and yaw rate sensor connector E-126 in good

condition?
YES : Go to Step 4.
NO : Repair or replace the connector, and then go to Step

9.

AC204175

CONNECTOR: E-126

HARNESS SIDE

E-126(GR)

E-126(GR)

AB

FLOOR
CONSOLE

1

2

4 3

AC204580

HARNESS SIDE: E-126

AO

1

2

4 3

AC204175

CONNECTOR: E-126

HARNESS SIDE

E-126(GR)

E-126(GR)

AB

FLOOR
CONSOLE

1

2

4 3

M-ASTC DIAGNOSIS

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MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-27

STEP 4. Check the wiring harness between G and yaw rate
sensor connector E-126 terminal 1 and the ignition switch
(IG1).

AC204175

CONNECTOR: E-126

HARNESS SIDE

E-126(GR)

E-126(GR)

AB

FLOOR
CONSOLE

1

2

4 3

AC204170

CONNECTOR: D-01

AB

9 10

8

6 7

31 32

30

29

18 19 20 21

5

4

2

1

3

27

26

24

23

25

12 13 14 15 16 17

28

11
22
33

AC204191

CONNECTORS: D-208, D-212

D-208

AN

HARNESS SIDE

HARNESS SIDE

D-212

D-208

D-212

1

2

3

5

6

4

7 6 5

2 1

9 8

11 10

4 3

M-ASTC DIAGNOSIS

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MITSUBISHI ACTIVE SKID AND TRACTION CONTROL SYSTEM

35C-28

NOTE: Also check joint connector D-01 and junction block con-
nector D-208 and D-212 and intermediate connector E-11 for
loose, corroded, or damaged terminals, or terminals pushed
back in the connectors. If joint connector D-01 or junction block
connector D-208 or D-212 or intermediate connector E-11 are
damaged, repair or replace the damaged component(s) as
described in GROUP 00E, Harness Connector Inspection

P.00E-2

. If the connector has been repaired or replaced, go to

Step 9.
Q: Is the wiring harness between G and yaw rate sensor

connector E-126 terminal 1 and the ignition switch (IG1)
in good condition?
YES : Go to Step 9.
NO : Repair the wiring harness, and then go to Step 9.

STEP 5. Check G and yaw rate sensor for ground circuit.
Measure at G and yaw rate sensor connector E-126.
(1) Disconnect G and yaw rate sensor connector E-126, and

measure the resistance at the harness-side connector.

(2) Measure the resistance between G and yaw rate sensor

connector E-126 terminal 4 and body ground.

• The resistance should measure 2 ohms or less.

Q: Does the resistance measure 2 ohms or less?

YES : Go to Step 8.
NO : Go to Step 6.

STEP 6. Check G and yaw rate sensor connector E-126.
Q: Is G and yaw rate sensor connector E-126 in good

condition?
YES : Go to Step 7.
NO : Repair or replace the connector, and then go to Step

9.

AC204176

CONNECTOR: E-11

AB

3

10

16

9

7 8

6

1

4

2

5

11

14

1213

15

AC204175

CONNECTOR: E-126

HARNESS SIDE

E-126(GR)

E-126(GR)

AB

FLOOR
CONSOLE

1

2

4 3

AC204581

HARNESS SIDE: E-126

AT

1

2

4 3

AC204175

CONNECTOR: E-126

HARNESS SIDE

E-126(GR)

E-126(GR)

AB

FLOOR
CONSOLE

1

2

4 3