Mitsubishi Montero (2002-2004). Manual - part 1000

HYDRAULIC BRAKE BOOSTER (HBB) DIAGNOSIS

TSB Revision

BASIC BRAKE SYSTEM

35A-25

STEP 2. Check the following connectors.

• HBB connector B-17 and B-18

Check connectors for loose, corroded or damaged terminals, or 
terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?

YES : Go to Step 3.
NO :  Repair the faulty connector or terminal and then go to 

Step 10.

STEP 3. Check the HBB ground circuit at HBB harness 
connector B-17.
(1) Disconnect HBB connector B-17 and measure at the 

harness connector (component side).

(2) Measure the resistance between terminal 7 and ground.

The resistance should measure less than 2 ohms.

Q: Is the measured resistance less than 2 ohms?

YES : Go to Step 4.
NO :  Repair the harness wire between HBB connector B-

17 (terminal 7) and ground. Then go to Step 10.

AC204629 AB

CONNECTORS: B-17, B-18

B-17 (GR)

B-18 (B)

B-17

B-18

HBB CONNECTORS

AC204629 AC

CONNECTOR: B-17

B-17 (GR)

HBB CONNECTOR

B-17

ACX01937

1

2

3

4

5

6

7

8

AC

HARNESS CONNECTOR: 
COMPONENT SIDE

B-17
(GR)

HYDRAULIC BRAKE BOOSTER (HBB) DIAGNOSIS

TSB Revision

BASIC BRAKE SYSTEM

35A-26

STEP 4. Check the HBB ground circuit at HBB harness 
connector B-18.
(1) Disconnect HBB connector B-18 and measure at the 

harness connector (component side).

(2) Measure the resistance between terminal 32 and ground.

The resistance should measure less than 2 ohms.

Q: Is the measured resistance less than 2 ohms?

YES : Go to Step 5.
NO :  Repair the harness wire between HBB connector B-

18 (terminal 32) and ground. Then go to Step 10.

AC204629 AD

CONNECTOR: B-18

B-18 (B)

HBB CONNECTOR

B-18

AC204550

34

32

31

33

35

HARNESS CONNECTOR: 
COMPONENT SIDE

AB

B-18 (B) 

HYDRAULIC BRAKE BOOSTER (HBB) DIAGNOSIS

TSB Revision

BASIC BRAKE SYSTEM

35A-27

STEP 5. Check the HBB (continuity and resistance test of 
the pump motor).
(1) Disconnect HBB connectors B-17 and B-18.

(2) Check for continuity and measure the resistance between 

terminals at the HBB connectors.

Q: Does continuity exist between above terminals?

YES : Go to Step 7.
NO :  Go to Step 6.

TESTER 
CONNECTION

SPECIFIED 
CONDITION

RESISTANCE 

Ω 

(REFERENCE VALUE)

2 

− 7

Continuity

10 or less

2 

− 8

Continuity

Approximately 33

2 

− 31

Continuity

Less than 2

4 

− 6

Continuity

Approximately 33

4 

− 32

Continuity

Approximately 33

6 

− 7

Continuity

Less than 2

6 

− 32

Continuity

Less than 2

7 

− 32

Continuity

Less than 2

8 

− 31

Continuity

Approximately 33

31 

− 32

Continuity

10 or less

AC204629 AB

CONNECTORS: B-17, B-18

B-17 (GR)

B-18 (B)

B-17

B-18

HBB CONNECTORS

ACX00662AC

B-18

B-17

HYDRAULIC BRAKE BOOSTER (HBB) DIAGNOSIS

TSB Revision

BASIC BRAKE SYSTEM

35A-28

STEP 6. Check the pump motor and lead wire.
(1) Remove the HBB (Refer to 

P.35A-133

).

(2) Remove the pump motor and the lead wire from the HBB 

(Refer to 

P.35A-136

).

(3) Check the following items:

• Confirm that the pump motor operates when the battery 

voltage is imposed at the pump motor terminal.

• Confirm the continuity of the lead wire.

Q: Are both of the pump motor and the lead wire in good 

condition?
YES : Replace the master cylinder and hydraulic unit 

assembly (Refer to 

P.35A-136

). Then go to Step 10.

NO :  Replace the pump motor or the lead wire (Refer to 

P.35A-136

). Then go to Step 10.

STEP 7. Check the following connector.

• M-ASTC-ECU connector E-119

Check connector, for loose, corroded or damaged terminals, or 
terminals pushed back in the connector.
Q: Are the connector and terminals in good condition?

YES : Go to Step 8.
NO :  Repair the faulty connector or terminal and then go to 

Step 10.

AC203901

AC204627 AB

CONNECTOR: E-119

E-119

M-ASTC-ECU CONNECTOR

E-119