Mitsubishi Montero (2002-2004). Manual — part 1016

HYDRAULIC BRAKE BOOSTER (HBB) DIAGNOSIS

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BASIC BRAKE SYSTEM

35A-89

STEP 8. Check the following harness wire.

• The wire between combination meter connector D-03 (ter-

minal 57) and ground

NOTE: Also check joint connector (8) D-30 for loose, corroded,
or damaged terminals, or terminals pushed back in the connec-
tor. If joint connector (8) D-30 is 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 harness wire damaged?

YES : Repair it and then go to Step 9.
NO : Go to Step 9.

STEP 9. Retest the system.
Q: Does the brake warning light illuminate for three

seconds when the ignition switch is turned to the "ON"
position with engine stopped?
YES : The procedure is complete.
NO : Start over at Step 1.

AC204690 AC

CONNECTOR: D-03

D-03 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

D-03

AC204690 AD

CONNECTOR: D-30

D-30

JOINT CONNECTOR (8):
JOINT PIN SIDE

D-30

HYDRAULIC BRAKE BOOSTER (HBB) DIAGNOSIS

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BASIC BRAKE SYSTEM

35A-90

INSPECTION PROCEDURE 2: The Brake Warning Light Remains Illuminated after the Engine is
Started.

CAUTION

First of all, check the parking brake switch circuit
and the brake fluid level switch circuit.
NOTE: This diagnosis procedure is limited to cases
where communication with the scan tool is possible
(M-ASTC-ECU power supply is normal) and no DTC
sets.

AC204501AB

Brake Warning Light Circuit

AC204687AC

CONNECTOR: D-03

D-03 (GR)

AC204548 AB

CONNECTOR: E-111

E-111

HYDRAULIC BRAKE BOOSTER (HBB) DIAGNOSIS

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BASIC BRAKE SYSTEM

35A-91

.

CIRCUIT OPERATION
When the power transistor in the M-ASTC-ECU is off
or the circuit between the M-ASTC-ECU and the
combination meter is open, the power transistor in
the combination meter will turn on to illuminate the
brake warning light.

.

TECHNICAL DESCRIPTION (COMMENT)
The cause is probably the M-ASTC-ECU malfunction
or open circuit at the M-ASTC-ECU’s brake warning
light drive circuit.

.

TROUBLESHOOTING HINTS

• Damaged wiring harness or connector

• Malfunction of the M-ASTC-ECU

• Malfunction of the combination meter

.

AC203901AG

CONNECTOR: E-121

E-121

HYDRAULIC BRAKE BOOSTER (HBB) DIAGNOSIS

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BASIC BRAKE SYSTEM

35A-92

DIAGNOSIS

Required Special Tool:

• MB991223: Harness Set

STEP 1. Check the following connectors.

• Combination meter connector D-03

• M-ASTC-ECU connector E-121

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 2.
NO : Repair the faulty connector or terminal and then go to

Step 4.

AC204690 AB

COMBINATION METER
CONNECTOR

D-03

CONNECTOR: D-03

D-03 (GR)

AC203901

AC204627AP

CONNECTOR: E-121

M-ASTC-ECU CONNECTOR

E-121

E-121