Mitsubishi Montero (2002-2004). Manual - part 841

AUTO-CRUISE CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-27

STEP 2. Using scan tool MB991502, read the diagnostic 
trouble code.

CAUTION

To prevent damage to scan tool MB991502, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check for A/T system diagnostic trouble code.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC 26 set?

YES : Refer to GROUP 23A, Diagnostic Trouble Code 

Procedures 

− DTC 26: Stoplight Switch System 

P.23Ac-83

.

NO :  Go to Step 3.

STEP 3. Using scan tool MB991502, check data list item 06: 
Stoplight Switch.

CAUTION

To prevent damage to scan tool MB991502, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991502. 
(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991502 to data reading mode for auto-

cruise control system item 06, Stoplight Switch.

• When the brake pedal is depressed, the display on scan 

tool MB991502 should be "ON."

• When the brake pedal is not depressed, the display on 

scan tool MB991502 should be "OFF."

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the switch operating properly?

YES : It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use Troubleshooting/
Inspection Service Points 

− How to Cope with 

Intermittent Malfunction 

P.00-6

.

NO :  Go to Step 4.

STEP 4. Check stoplight switch connector D-123 for 
looser, corroded or damaged terminals, or terminals 
pushed back in the connector.
Q: Are the connector and terminals in good condition?

YES : Go to Step 5.
NO :  Repair or replace the damaged components. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-

2

.

ACX02258AC

MB991502

16-PIN

ACX02258AC

MB991502

16-PIN

1

2

3

4

AC204682AB

CONNECTOR: D-123

D-123 

AUTO-CRUISE CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-28

STEP 5. Measure the stoplight switch power supply 
voltage at connector D-123 by backprobing.
(1) Do not disconnect connector D-123.
(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal 3 and ground by 

backprobing.

• When the brake pedal is depressed, voltage should 

measure battery positive voltage.

• When the brake pedal is not depressed, voltage should 

measure less than 1 volt.

Q: Does the voltage measure the battery positive voltage 

when the brake pedal is depressed, and measure one 
volt or less when the pedal is released?
YES : Go to Step 8.
NO :   Go to Step 6.

1

2

3

4

AC204682AB

CONNECTOR: D-123

D-123 

2

1

3

4

AC205055AB

D-123 HARNESS 
CONNECTOR:
HARNESS SIDE

AUTO-CRUISE CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-29

STEP 6. Check stoplight switch connector D-123, 
intermediate connector D-125, intermediate connector E-
110 and PCM connector D-133 for looser, corroded or 
damaged terminals, or terminals pushed back in the 
connector.

1

2

3

4

AC204682AB

CONNECTOR: D-123

D-123 

AC205043

CONNECTOR: D-125

D-125 

AB

AUTO-CRUISE CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-30

Q: Are the connectors and terminals in good condition?

YES : Go to Step 7.
NO :  Repair or replace the damaged components. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-

2

.

AC205045

6

1

7

2

9

8

10

3

5

12

11

4

1314

E-110

CONNECTOR: E-110

AB

AC205046

CONNECTOR: D-133

D-133(GR)

PCM

AB