Mitsubishi Montero (2002-2004). Manual - part 1050

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-71

DTC 61 : Master Cylinder Pressure Sensor System

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CIRCUIT OPERATION
The master cylinder pressure sensor is monitoring 
the brake fluid pressure to the rear wheels. The mas-
ter cylinder pressure sensor sends a signal from its 
terminal No.1, and the M-ASTC-ECU receives the 
signal at its connector No.59.

.

ABS DTC SET CONDITIONS
DTC 61 is set in the following case.

• When the power supply voltage is abnormally 

high or low

• When the master cylinder pressure sensor output 

signal is abnormally high or low

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TROUBLESHOOTING HINTS

• Damaged wiring harness or connector

• Malfunction of the master cylinder pressure sen-

sor

• Malfunction of the M-ASTC-ECU

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DIAGNOSIS

Required Special Tool:

• MB991223: Harness Set 

Master Cylinder Pressure Sensor Circuit

AC204772AB

B-55(GR)

CONNECTOR: B-55

AC203901AF

CONNECTOR: E-120

E-120

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-72

STEP 1. Check the power supply circuit at pressure sensor 
connector B-55.
(1) Do not disconnect pressure sensor connector B-55.
(2) Turn the ignition switch to the "ON" position.
(3) Measure voltage between terminal 2 and ground. It should 

be approximately 5 volts.

Q: Is the voltage approximately 5 volts?

YES : Go to Step 4.
NO :  Go to Step 2.

STEP 2. Check the M-ASTC-ECU connectors E-120.
(1) Disconnect the M-ASTC-ECU connector E-120.
(2) Turn the ignition switch to the "ON" position.
(3) Measure voltage between terminal 50 and ground. It should 

be approximately 5 volts.

Q: Is the voltage approximately 5 volts?

YES : Go to Step 3.
NO :  Replace the M-ASTC-ECU and go to Step 10.

AC204772

AC204773AB

B-55(GR)

CONNECTOR: B-55

1

3

2

HARNESS CONNECTOR:
COMPONENT SIDE

AC203901

AC204627AV

CONNECTOR: E-120

E-120

ASC-ECU CONNECTOR:
HARNESS SIDE

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-73

STEP 3. Check the harness wires between M-ASTC-ECU 
connector E-120 terminal 50 and pressure sensor 
connector B-55 terminal 2.
Q: Is the harness wire between M-ASTC-ECU connectors 

E-120 terminal 50 and pressure sensor connector B-55 
terminal 2 damaged?
YES : Repair it and then go to Step 10.
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

.

AC203901

AC204627AG

CONNECTOR: E-120

E-120

HARNESS CONNECTOR: 
COMPONENT SIDE

E-120

AC204772AC

B-55(GR)

CONNECTOR: B-55

1

3

2

HARNESS CONNECTOR:
COMPONENT SIDE

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-74

STEP 4. Check the ground circuit at pressure sensor 
connector B-55.
(1) Disconnect the pressure sensor connector B-55, and 

measure at the harness side.

(2) Measure the resistance between terminal 3 and ground. It 

should be less than 2 ohms.

Q: Is there continuity between the terminal number 3 and 

ground?
YES : Go to Step 7.
NO :  Go to Step 5.

AC204772

AC204773AC

B-55(GR)

CONNECTOR: B-55

1

3

2

HARNESS CONNECTOR:
HARNESS SIDE