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

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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

13Ac-410

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

13Ac-411

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

13Ac-412

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