Mitsubishi Montero (2004+). Manual - part 1068

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-115

Q: Is the harness wire between combination meter

connector D-03 terminal 56 and M-ASTC-ECU connector
E-106 terminal 62 damaged?
YES : Repair it and then go to Step 3.
NO : This malfunction is intermittent. Refer to GROUP 00,

How to Use Troubleshooting/Inspection Service
Points

− How to Cope with Intermittent Malfunction

P.00-6

STEP 3. Retest the system.
Q: Does the ABS warning light illuminate for 3 seconds

when the ignition switch is turned to the "ON" position
with engine stopped or upon start-up?
YES : The procedure is complete.
NO : Return to Step 1.

INSPECTION PROCEDURE 6: Faulty ABS Operation

TECHNICAL DESCRIPTION (COMMENT)
The cause depends on driving and road surface con-
ditions, so diagnosis may be difficult. However, if no
diagnostic trouble code is displayed, carry out the fol-
lowing inspection.

TROUBLESHOOTING HINTS

• Malfunction of the hydraulic brake booster (HBB)

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

STEP 1. Check the HBB hydraulic unit.
Check the operation of HBB hydraulic unit. Refer to

P.35B-126

Q: Does HBB hydraulic unit operate normally?

YES : Intermittent malfunction of the vehicle speed sensor is

assumed to be the cause. Refer to GROUP 00, How
to Use Troubleshooting/Inspection Service Points

−

How to Cope With Intermittent Malfunction

P.00-6

Then go to Step 2.

NO : Replace the HBB master cylinder and hydraulic unit

assembly and go to Step 2.

STEP 2. Retest the system.
Q: Do the brakes operate normally?

YES : The procedure is complete.
NO : Return to Step 1.

AC204385

CONNECTOR: E-110

E-110

1314

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-116

DATA LIST REFERENCE TABLE

M1352011500638

The following items can be read by the scan tool
from the M-ASTC-ECU input data.

MUT-III
SCAN TOOL
DISPLAY*

ITEM
NO.

CHECK ITEM

CHECKING REQUIREMENTS

NORMAL VALUE

ACCUM
SW(PH)

Accumulator switch (PH) Accumulator fluid pressure

reduces to less than approx. 16.1
MPa

Accumulator fluid pressure
reaches approx. 18.3 MPa

OFF

ACCUM
SW(PL)

Accumulator switch (PL) Accumulator fluid pressure

reduces to approx. 10.8 MPa or
less.

M-ASTC OFF
SW

Active skid control
switch

Set the active skid control switch
to the neutral position

OFF

Turn the active skid control switch
to the OFF position

M-ASTC ON
SW

Active skid control
switch

Set the active skid control switch
to the neutral position

OFF

Turn the active skid control switch
to the ON position

BATT.
VOLTAGE

M-ASTC-ECU power
supply voltage

Ignition switch power supply
voltage and valve monitor voltage

6.5

− 22.3 V

ENGINE
SPEED

Engine speed

Drive the vehicle

The scan tool and the
tachometer readings
are approximately the
same

EN.
TYPE/DEST
N

Engine model and
destination

−

6G75 NAS

FR SNSR

Front right ABS sensor

Drive the vehicle

Vehicle speeds
displayed on the
speedometer and
scan tool are identical.

FL SNSR

Front left ABS sensor

G SENS
VOLT 1

Output 1 from G sensor Drive the vehicle

-14.7

− 14.7 m/s

G SENS
VOLT 2

Output 2 from G sensor

G SENSOR
VOLT

Output from G sensor
(longitudinal
acceleration)

G
S(LATERAL)

Output from G sensor
(lateral acceleration)

IDLE POS.
SW

Closed throttle position
switch

Do not depress the accelerator
pedal

Depress the accelerator pedal

OFF

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-117

TR SWITCH

Transmission range
switch

Drive the vehicle

The shift lever position
indicator and the scan
tool readings are
equal

M/C PRESS.
SNSR

Master cylinder pressure
sensor

When depressing gradually the
brake pedal, the output value will
change.

Approximately 0.5 -
4.5 V

MOTOR RLY 79

Motor relay

Motor relay is operating

Motor relay is not operating

OFF

RR SNSR

Rear right ABS sensor

Drive the vehicle

Vehicle speeds
displayed on the
speedometer and
scan tool are identical.

RL SNSR

Rear left ABS sensor

SHIFT
POSIT.

Shift position

Drive the vehicle

The shift lever position
indicator and the scan
tool readings are
equal

ST ANGLE

Steering wheel angle

deg (approximately
the same as actual
steering wheel angle)

STOPLIGHT
SW

Stoplight switch

Depress the brake pedal.

Release the brake pedal.

OFF

T/F MODE

Transfer position

Drive the vehicle.

the same as actual
transfer position

VALVE RLY

Valve relay

Valve relay is operating

Valve relay is not operating

OFF

MUT-III
SCAN TOOL
DISPLAY*

ITEM
NO.

CHECK ITEM

CHECKING REQUIREMENTS

NORMAL VALUE

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-118

ACTUATOR TEST REFERENCE

M1352011600635

CAUTION

When performing the item No.09 [AIR BLEEDING
(1)] consecutively, keep the interval of 20 sec-
onds or more between respective bleeding oper-
ations.
The scan tool activates the following actuators for
testing.

NOTE: If the M-ASTC-ECU is inoperative, actuator
testing cannot be carried out.
NOTE: Actuator testing is only possible when the
vehicle is stationary. If the vehicle speed during actu-
ator testing exceeds 10 km/h (6 mph), forced actua-
tion will be canceled.

ACTUATOR TEST SPECIFICATIONS

MUT-III SCAN
TOOL DISPLAY

ITEM
NO.

CHECK ITEM

PARTS TO BE
ACTIVATED

Activation
when the
system fails

FR ABS VALVE

Solenoid valve for front-right wheel HBB select solenoid valves

and control solenoid valves
for the respective channel

Disabled

FL ABS VALVE

Solenoid valve for front-left wheel

RR ABS VALVE

Solenoid valve for rear-right wheel

RL ABS VALVE

Solenoid valve for rear-left wheel

ABS AIR B.1

Air bleeding (1)

HBB select solenoid valves
and control solenoid valve
OUT (FR, FL)

Disabled

ABS AIR B.2

Air bleeding (2)

HBB control solenoid valve
OUT (RR, RL)

Disabled

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