Mitsubishi Montero (2002-2004). Manual - part 678

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-409

DIAGNOSIS

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

STEP 1. Using scan tool MB991502, check evaporative 
emission system monitor test.

CAUTION

• To prevent damage to scan tool MB991502, always turn 

the ignition switch to the "LOCK" (OFF) position before 
connecting or disconnecting scan tool MB991502.

• During this test, the PCM automatically increases the 

engine speed to 1,600 r/min or greater. Check that the 
transmission is set to "P" position.

(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Erase the DTCs using scan tool MB991502. (Refer to 

GROUP 13A, Trouble Code Diagnosis 

P.13Ab-2

).

(4) Check that the fuel cap is securely closed. (Tighten until 

three clicks are heard).

(5) Start the engine.
(6) Select "System Test" and press the "YES" key.
(7) Select "Evap Leak Mon" and press the "YES" key.
(8) During this test, keep the accelerator pedal at the idling 

position.

(9) Keep the engine speed and engine load within the specified 

range. When the monitor test starts, the "In Progress" item 
on scan tool MB991502 will change from "NO" to "YES".

(10)Turn the ignition switch to the "LOCK" (OFF) position and 

disconnect scan tool MB991502.

Q: What is displayed on scan tool MB991502?

"Evap Leak Mon. Completed Test Passed" : The EVAP 

system is working properly at this time. Explain to the 
customer that an improperly tightened fuel cap can 
cause MIL to turn on. Return the vehicle to the 
customer.

"Evap Leak Mon. Completed. Test Failed and DTCs Set" 
: 

A malfunction has been detected during the monitor 
test. Refer to GROUP 13A, Diagnostic Trouble Code 
Chart 

P.13Ab-22

, and diagnose any other DTCs that 

are set. If no other DTCs have been set, go to Step 2.

"Evap Lead Mon. Discontinued. Retest again from the 
first" : The EVAP monitor was interrupted during the test. 

Turn the ignition switch to the "LOCK" (OFF) position 
once, and repeat the monitoring from Step 1.

ACX01543

MB991502

AB

16-PIN

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DIAGNOSTIC TROUBLE CODE PROCEDURES

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STEP 2. Check for leaks in the evaporative emission purge 
solenoid.
(1) Disconnect hose B from the evaporative emission purge 

solenoid and connect a hand vacuum pump to the nipple of 
the evaporative emission purge solenoid.

(2) Use the hand vacuum pump to confirm that the evaporative 

emission purge solenoid holds vacuum.

(3) Disconnect the hand vacuum pump and connect hose B to 

the evaporative emission purge solenoid.

Q: Does the evaporative emission purge solenoid hold 

vacuum?
YES : Go to Step 3.
NO :  Replace the evaporative emission purge solenoid. Go 

to Step 18.

STEP 3. Check for leaks in the evaporative emission 
system hose A and hose B.

Perform a leakage test with a hand vacuum pump on each 
hose A and B.

Q: Does the hoses hold vacuum?

YES : Go to Step 4.
NO :  Replace any damaged hose. Go to Step 18.

AC203994 AB

HOSE A

HOSE B

EVAPORATIVE EMISSION

PURGE SOLENOID

AC203996

AB

EVAPORATIVE EMISSION

PURGE SOLENOID

AC203994 AB

HOSE A

HOSE B

EVAPORATIVE EMISSION

PURGE SOLENOID

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DIAGNOSTIC TROUBLE CODE PROCEDURES

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STEP 4. Check the evaporative emission ventilation 
solenoid using scan tool MB991502 (Actuator test item 29).

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) Disconnect hose S from the evaporative emission 

ventilation solenoid and connect a hand vacuum pump.

(3) Turn the ignition switch to the "ON" position.
(4) Set scan tool MB991502 to actuator test mode for item 29: 

Evaporative Emission Ventilation Solenoid Valve. While the 
evaporative emission ventilation solenoid is energized, 
operate the hand vacuum pump and confirm that solenoid 
holds vacuum.

(5) Turn the ignition switch to the "LOCK" (OFF) position and 

disconnect scan tool MB991502.

(6) Disconnect the hand vacuum pump and connect hose S to 

the evaporative emission ventilation solenoid.

Q: Does the evaporative emission ventilation solenoid hold 

vacuum?
YES : Go to Step 5.
NO :  Replace the evaporative emission ventilation 

solenoid. (Refer to GROUP 17, Evaporative Emission 
Canister and Fuel Tank Pressure Relief Valve 

P.17-

66

). Go to Step 18.

STEP 5. Check for leaks in the evaporative emission 
system hose S.

Perform a leakage test with a hand vacuum pump on hose 
S.

Q: Does hose S hold vacuum?

YES : Go to Step 6.
NO :  Replace hose S. Go to Step 18.

ACX01539

16-PIN

MB991502

AC

AC101769

HOSE S

AC

EVAPORATIVE EMISSION

VENTILATION SOLENOID

AC102452

HOSE S

AC

OVER VENT

VALVE

MODULE

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DIAGNOSTIC TROUBLE CODE PROCEDURES

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STEP 6. Check for leaks in the evaporative emission 
system hose E.

Perform a leakage test with a hand vacuum pump on hose 
E.

Q: Does hose E hold vacuum?

YES : Go to Step 7.
NO :  Replace hose E. Go to Step 18.

STEP 7. Pressure test the evaporative emission system 
lines between hose F and R.
(1) Disconnect hose F from the evaporative emission canister 

and plug hose F securely.

(2) Confirm that the evaporative emission system pressure 

pump (Miller number 6872A) is operating properly. Perform 
the self-test as described in the manufacturer's instructions.

(3) Remove the fuel cap.

(4) Connect the evaporative emission system pressure pump 

to the fuel tank filler tube.

(5) Pressure test the system to determine whether any leaks 

are present.
NOTE: The "Pressure test" in this procedure refers to the I/
M240 Simulation Test. The eight steps of this test are 
described in the manufacturer's instructions for the evapo-
rative emission system pressure pump, Miller number 
6872A.

(6) Disconnect the evaporative emission system pressure 

pump and reinstall the fuel cap.

(7) Connect hose F to the evaporative emission canister.
Q: Is the evaporative emission system line free of leaks?

YES : Go to Step 15.
NO :  Go to Step 8.

AC101772

HOSE E

AC

EVAPORATIVE EMISSION

CANISTER

AC102602 AC

HOSE F

ACX01358