Mitsubishi Montero (2002-2004). Manual - part 843

AUTO-CRUISE CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-35

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 any DTC set?

YES : Refer to GROUP 23A, Diagnosis 

− Diagnostic 

Trouble Code Chart 

P.23Ab-31

.

NO :  Replace the PCM. (Refer to 

P.17-54

.) Check that 

diagnostic trouble code 23 is not set.

SYMPTOM CHART

M1172002300281

ACX02258AC

MB991502

16-PIN

SYMPTOM

INSPECTION 
PROCEDURE NO.

REFERENCE 
PAGE

Communication with 
scan tool is not 
possible

Communication with all systems is 
impossible

-

Group 13A, 
diagnosis 

P.13Ad-

2

.

Communication with the PCM only is 
impossible

-

Group 13A, 
diagnosis 

P.13Ad-

5

.

Auto-cruise control 
is not cancelled.

When brake pedal is depressed

1

P.17-36

When selector lever is moved to "N" range  2

P.17-36

When "CANCEL" switch is turned ON

3

P.17-36

Auto-cruise control cannot be set.

4

P.17-37

Hunting (repeated acceleration and deceleration) occurs at the 
set vehicle speed.

5

P.17-38

Auto-cruise control indicator light inside combination meter does 
not illuminate. (However, auto-cruise control is normal.)

6

P.17-39

AUTO-CRUISE CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-36

SYMPTOM PROCEDURES

INSPECTION PROCEDURE 1: When the Brake Pedal is Depressed, Auto-cruise Control is not 
Cancelled.

.

COMMENT
The stop light switch circuit is suspected.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this case:)

• Malfunction of the stoplight switch.

• Damaged harness or connector.

• Malfunction of the PCM.

DIAGNOSIS

.

Refer to 

P.17-24

, Diagnostic Trouble Code Procedures 

− DTC 

22: Stoplight Switch System.

INSPECTION PROCEDURE 2: When the Selector Lever is Moved to "N" Range, Auto-cruise Control is 
not Cancelled.

.

COMMENT
The transmission range switch circuit is suspected.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this case:)

• Malfunction of the transmission range switch.

• Damaged harness or connector.

• Malfunction of the PCM.

DIAGNOSIS

.

Refer to GROUP 23A, Diagnostic Trouble Code Procedures 

− 

DTC 27: Transmission Range Switch System (Open Circuit) 

P.23Ac-93

, DTC 28: Transmission Range Switch System 

(Short Circuit) 

P.23Ac-123

.

INSPECTION PROCEDURE 3: When the Auto-cruise Control "CANCEL" Switch is Set to ON, Auto-
cruise Control is not Cancelled.

.

COMMENT
The cause is probably an open-circuit in the output in 
the circuit inside the "CANCEL" switch.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this case:)

• Malfunction of the auto-cruise control switch.

DIAGNOSIS

.

Replace the auto-cruise control switch. Refer to 

P.17-54

, Auto-

cruise Control.

AUTO-CRUISE CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-37

INSPECTION PROCEDURE 4: Auto-cruise Control cannot be Set.

.

COMMENT
The fail-safe function is probably cancelling auto-
cruise control. In this case, scan tool MB991502 can 
be used to check the trouble symptoms in each sys-
tem by checking the diagnostic trouble codes. The 
scan tool can also be used to check if the circuits of 
each input switch are normal or not by checking the 
input switch codes. 

.

TROUBLESHOOTING HINTS (The most likely 
causes for this case:)

• Malfunction of the auto-cruise control switch.

• Malfunction of the PCM.

DIAGNOSIS

.

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

STEP 1. 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 auto-cruise control system diagnostic trouble 

code.

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

YES : Refer to 

P.17-12

, Diagnostic Trouble Code Chart.

NO :  Go to Step 2.

ACX02258AC

MB991502

16-PIN

AUTO-CRUISE CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-38

STEP 2. Using scan tool MB991502, check data list item 04: 
Cancel Switch, item 07: Transmission Range 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 04, Cancel Switch.

• When "CANCEL" switch is at the ON position, the dis-

play on scan tool MB991502 should be "ON."

• When "CANCEL" switch is at the OFF position, the dis-

play on scan tool MB991502 should be "OFF."

(4) Set scan tool MB991502 to data reading mode for auto-

cruise control system item 07, Transmission Range Switch.

• When selector lever is at the "P" or "N" position, the dis-

play on scan tool MB991502 should be "ON."

• When selector lever is at the "R" or "D" position, the dis-

play on scan tool MB991502 should be "OFF."

(5) 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 :  Follow the symptom procedures below. 

• Item 04: 

Refer to 

P.17-36

, Symptom Procedures number 3. 

• 

Item 07: Refer to 

P.17-36

, Symptom Procedures 

number 2.

INSPECTION PROCEDURE 5: Hunting (Repeated Acceleration and Deceleration) Occurs at the Set 
Vehicle Speed.

.

COMMENT
The vehicle speed sensor or the throttle body is sus-
pected.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this case:)

• Malfunction of the vehicle speed sensor.

• Malfunction of the throttle body.

• Malfunction of the PCM.

DIAGNOSIS

.

Check for MFI system diagnostic trouble code. Refer to 
GROUP 13A, Trouble Code Diagnosis 

P.13Ab-2

.

ACX02258AC

MB991502

16-PIN