Mitsubishi Montero (2004+). Manual - part 407

AUTO-CRUISE CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-35

STEP 8. Check the resistance of the ground circuit at 
stoplight switch connector D-123.
(1) Disconnect stoplight switch connector D-123 and measure 

at the harness side.

(2) Check the resistance between terminal 4 and ground.

• The resistance should measure less than 2 ohms.

Q: Is the resistance less than 2 ohms?

YES : Go to Step 10.
NO :  Go to Step 9.

STEP 9. Check the harness for an open circuit or damage 
between stoplight switch connector D-123 terminal 4 and 
ground.
Q: Is the harness wire in good condition?

YES : Go to Step 10.
NO :  Repair or replace the harness wire.

1

2

3

4

AC204682AB

CONNECTOR: D-123

D-123 

2

1

3

4

AC205056AB

D-123 HARNESS
CONNECTOR: 
COMPONENT SIDE

1

2

3

4

AC204682AB

CONNECTOR: D-123

D-123 

AUTO-CRUISE CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-36

STEP 10. Check the stoplight switch.
(1) Disconnect stoplight switch connector D-123.
(2) Remove the stoplight switch and measure at the stoplight 

switch side.

(3) Measure the resistance value between terminals 3 and 4.

• The resistance value should measure two ohms or less 

when the plunger is pushed within 4.5 mm (0.2 inch) 
from the outer case end.

Q: Does the resistance value measure two ohms or less 

when the plunger is pushed within 4.5 mm (0.2 inch) 
from the outer case end?
YES : Go to Step 11.
NO :  Replace the stoplight switch. Refer to GROUP 35A, 

Brake Pedal 

P.35A-136

.

1

2

3

4

AC204682AB

CONNECTOR: D-123

D-123 

1

2

3

4

ACX01917

D-123 STOPLIGHT 
SWITCH CONNECTOR

AG

AC205057    

CONTINUITY

NO
CONTINUITY

4.0 mm (0.16 in)

AB

AUTO-CRUISE CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-37

STEP 11. Using scan tool MB991958, check data list item 
06: Stoplight Switch.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958. 
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991958 to data reading mode.

Item 06 auto-cruise control system, Stoplight Switch.

• When the brake pedal is depressed, the display on 

scan tool MB991958 should be "ON."

• When the brake pedal is not depressed, the display 

on scan tool MB991958 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 :  Replace the PCM. Refer to 

P.17-58

, Auto-cruise 

Control.

DTC 23: Powertrain Control module (PCM) and Its Related Components

.

DTC SET CONDITIONS
This DTC is set when there is an failure in the PCM 
and its related components.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this code to be set are:)

• Malfunction of the MFI system.

• Malfunction of the A/T system.

• Malfunction of the PCM.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan tool (MUT-III sub assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB cable

• MB991911: MUT-III main harness B

• MB991223: Harness set

AC306409AF

MB991911

MB991824

MB991827

AUTO-CRUISE CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-38

STEP 1. Using scan tool MB991958, read the diagnostic 
trouble code.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check for MFI system diagnostic trouble code.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is any DTC set?

YES : Refer to GROUP 13A, Diagnosis 

− Diagnostic 

Trouble Code Chart 

P.13A-26

.

NO :  Go to Step 2.

STEP 2. Using scan tool MB991958, read the diagnostic 
trouble code.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 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 any DTC set?

YES : Refer to GROUP 23A, Diagnosis 

− Diagnostic 

Trouble Code Chart 

P.23A-41

.

NO :  Replace the PCM. (Refer to 

P.17-58

.) Check that 

diagnostic trouble code 23 is not set.

AC306409AF

MB991911

MB991824

MB991827

AC306409AF

MB991911

MB991824

MB991827