Mitsubishi Montero (2002-2004). Manual — part 1006

HYDRAULIC BRAKE BOOSTER (HBB) DIAGNOSIS

TSB Revision

BASIC BRAKE SYSTEM

35A-49

STEP 17. Check the ignition switch (IG2) circuit at M-
ASTC-ECU harness connector E-119.
(1) Disconnect M-ASTC-ECU connector E-119.
(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal 24 and ground. The

voltage should measure approximately 12 volts (battery
positive voltage).

Q: Is battery positive voltage (approximately 12 volts)

present?
YES : Go to Step 20.
NO : Go to Step 19.

AC203901

AC204627 AB

CONNECTOR: E-119

E-119

M-ASTC-ECU CONNECTOR

E-119

AC204631AB

HARNESS CONNECTOR:
COMPONENT SIDE

E-119

HYDRAULIC BRAKE BOOSTER (HBB) DIAGNOSIS

TSB Revision

BASIC BRAKE SYSTEM

35A-50

STEP 18. Check the following harness wire.

• The wire between M-ASTC-ECU connector E-120 (terminal

48) and motor relay A connector B-53X (terminal 1)

Q: Is the harness wire damaged?

YES : Repair or replace it and then go to Step 25.
NO : Go to Step 25.

AC203901

AC204627AG

CONNECTOR: E-120

E-120

HARNESS CONNECTOR:
COMPONENT SIDE

E-120

AC204551

3 2 1

5 4

1 2 3

4 5

RELAY BOX CONNECTOR

AC

CONNECTOR: B-53X

B-53X

HYDRAULIC BRAKE BOOSTER (HBB) DIAGNOSIS

TSB Revision

BASIC BRAKE SYSTEM

35A-51

STEP 19. Check the following harness wire.

• The wire between M-ASTC-ECU connector E-119 (terminal

24) and motor relay B connector B-54X (terminal 1)

Q: Is the harness wire damaged?

YES : Repair or replace it and then go to Step 25.
NO : Go to Step 25.

AC203901

AC204627AC

CONNECTOR: E-119

E-119

HARNESS CONNECTOR:
COMPONENT SIDE

E-119

AC204551

3 2 1

5 4

1 2 3

4 5

RELAY BOX CONNECTOR

AD

CONNECTOR: B-54X

B-54X

HYDRAULIC BRAKE BOOSTER (HBB) DIAGNOSIS

TSB Revision

BASIC BRAKE SYSTEM

35A-52

STEP 20. 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 22.
NO : Go to Step 21.

STEP 21. 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 25.

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

P.35A-136

). Then go to Step 25.

TESTER
CONNECTION

SPECIFIED
CONDITION

RESISTANCE

Ω

(REFERENCE VALUE)

2

− 7

Continuity

10 or less

2

− 31

Continuity

Less than 2

4

− 32

Continuity

Approximately 33

7

− 32

Continuity

Less than 2

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