Mitsubishi Montero (2004+). Manual — part 1050

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-43

.

CIRCUIT OPERATION
The ON signal when the brake pedal is pressed or
the OFF signal when the brake pedal is released is
input to the M-ASTC-ECU (terminal 19).

.

ABS DTC SET CONDITION
DTC 33 is set in the following cases:

• Stoplight switch is not operating properly and

remains in ON state for more than 15 minutes.

• Stoplight switch system harness is damaged and

no signal is input to M-ASTC-ECU.

.

TROUBLESHOOTING HINTS

• Malfunction of the stoplight switch

• Damaged wiring harness and connector

• Malfunction of the M-ASTC-ECU

.

DIAGNOSIS

Required Special Tools:

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

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

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness B

• MB991223: Harness Set

STEP 1. Check the stoplight operation.
Q: Does the stoplight come on and go out correctly?

YES : Go to Step 5.
NO : Go to Step 2.

STEP 2. Check the stoplight switch installation condition.
Q: Is the stoplight switch installed properly?

YES : Go to Step 3.
NO : Repair it and then go to Step 8.

AC204384

D-116

AD

CONNECTOR: D-116

AC204548

E-111

AM

CONNECTOR: E-111

AC203901AE

CONNECTOR: E-119

E-119

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

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ANTI-LOCK BRAKING SYSTEM (ABS)

35B-44

STEP 3. Check the stoplight switch continuity.

(1) Remove the stoplight switch (Refer to GROUP 35A, Brake

Pedal

P.35A-136

).

(2) Connect an ohmmeter between to stoplight switch

connector terminals.

(3) There should be no continuity between the terminals when

the plunger is pushed in as shown. There should be
continuity when it is released.

Q: Is the stoplight switch continuity correct?

YES : Go to Step 4.
NO : Replace it and then go to Step 8.

STEP 4. Check the harness wire between dedicated fuse
number 16 and stoplight switch connector D-123 terminal

2.

TESTER
CONNECTION

PLUNGER

SPECIFIED
CONDITION

1

− 2

IN

Open circuit

OUT

Less than 2 ohms

ACX00671AB

NO CONTINUITY CONTINUITY

4 mm

(0.16 in)

AC204676 AB

DETICATED FUSE No.16

RELAY BOX

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

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ANTI-LOCK BRAKING SYSTEM (ABS)

35B-45

NOTE: After inspecting intermediate connectors D-28,D-125
and stoplight switch connector D-123, inspect the wire. If inter-
mediate connectors D-28,D-125 and stoplight switch connector
D-123 are damaged, repair or replace them. Refer to GROUP
00E, Harness Connector Inspection

P.00E-2

. If the connector

has been repaired or replaced, go to Step 8.
Q: Is the harness wire between dedicated fuse number 16

and stoplight switch connector D-123 terminal 2
damaged?
YES : Repair it and then go to Step 8.
NO : Check the harness wire between stoplight connector

D-123 terminal 1 and stoplight, and repair if
necessary. Then go to Step 8.

STEP 5. Using scan tool MB991958, check data list.

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) Start the engine.

(3) Set scan tool MB991958 to the data reading mode, and

check the data list items by driving the vehicle.

• Item 36: STOPLIGHT SW

• ON with brake pedal stepped down.

• OFF with brake pedal released.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the stoplight switch input normal?

YES : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

− How to

Cope with Intermittent Malfunction

P.00-6

.

NO : Go to Step 6.

AC204677

AC204701AB

CONNECTORS: D-28, D-123, D-125

D-28

D-125

D-123

38

1213

11

26

14

1

20

6

232425

37

31

36

30

10

9

2122

35

8

7

34

17

29

1819

5

4

1516

33

28

32

27

3

2

D-28

9

21

33

35

24

12

3 4

7

8

5 6

39

28

41

30

18

4243

31

1920

32

40

29

1617

38

27

15

37

36

26

14

13

25

2

1

34

23

11

10

22

D-125

4

2

3

1

D-123

HARNESS CONNECTOR:

COMPONENT SIDE

AC307591 AB

MB991911

DATA LINK

CONNECTOR

MB991824

MB991827

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

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ANTI-LOCK BRAKING SYSTEM (ABS)

35B-46

STEP 6. Check the stoplight switch circuit at M-ASTC-ECU
connector E-119.

(1) Disconnect connector E-119 and measure at the harness

side.

(2) Turn the stoplight switch ON.
(3) Measure the voltage between terminal 19 and ground. It

should be approximately 12 volts (battery positive voltage).

Q: Is the voltage approximately 12 volts (battery positive

voltage)?
YES : Replace the M-ASTC-ECU and then go to Step 8.
NO : Go to Step 7.

AC203901

AC204627AH

CONNECTOR: E-119

E-119

HARNESS CONNECTOR:
COMPONENT SIDE

E-119