Mitsubishi Montero (2002-2004). Manual - part 693

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DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-469

CIRCUIT OPERATION

• The PCM (terminal 97) supplies a 5-volt refer-

ence signal to the fuel tank differential pressure
sensor (terminal 3). The fuel tank differential
pressure sensor (terminal 2) is grounded through
the PCM (terminal 96).

• The fuel tank differential pressure sensor (termi-

nal 1) returns a voltage signal to the PCM (termi-
nal 82) that is proportional to the pressure in the
fuel tank.

TECHNICAL DESCRIPTION

• The PCM monitors the fuel tank differential pres-

sure sensor output voltage.

• The PCM determines whether the fuel tank differ-

ential pressure sensor signal voltage is within
normal operating parameters.

DTC SET CONDITIONS

Test Conditions:

• Intake air temperature is between 5°C (41°F) and

°C (113°F) or greater.

• Engine speed is greater than 1,600 r/min.

• Volumetric efficiency is between 25 and 80 per-

cent.

Judgment Criteria:

• When the evaporative emission purge solenoid is

fully operational (100 percent ratio), the fuel dif-
ferential pressure sensor output voltage remains
4.0 volts or greater for ten seconds.

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

• Malfunction of the fuel tank differential pressure

sensor.

• A damaged harness in the fuel tank differential

pressure sensor circuit.

AC203998

CONNECTOR: D-112

D-112

AC203993

CONNECTORS: D-134, D-135

D-134
(GR)

D-135
(GR)

PCM

AC203999

CONNECTORS: E-111, E-113

E-113

E-111

AC204000

CONNECTOR: F-07

F-07 (B)

ACX00218

CONNECTOR : G-05

G-05 (B)

SECOND SEAT UNDER
SERVICE HOLE

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DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-470

• Malfunction of the PCM.

OVERVIEW OF TROUBLESHOOTING

• DTC P0453 can be set by a faulty fuel tank differ-

ential pressure sensor or related circuit, or PCM
failure.

• To check a system blockage, do a performance

test which uses a mechanical vacuum gauge and
scan tool MB991502 set on the fuel tank differen-
tial pressure sensor (TANK PRS SNSR 73).
The mechanical gauge reading is used to verify
scan tool MB991502 reading.
A comparison of the mechanical gauge with the
reading on scan tool MB991502 will locate a
problem in the system.

DIAGNOSIS

Required Special Tools:

• MB991502: Scan Tool (MUT-II)

• MB991658: Test Harness Set

STEP 1. Using scan tool MB991502, check data list item 73:
Fuel Tank Differential Pressure Sensor.

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 F from the evaporative emission canister

side, and plug the hose.

(3) Turn the ignition switch to the "ON" position.
(4) Remove the fuel cap.
(5) Set scan tool MB991502 to the data reading mode for item

73, Fuel Tank Differential Pressure Sensor.

• The fuel tank pressures reading on the scan tool should

−3.3 to 3.3 kPa (−0.97 to 0.97 inHg).

(6) Connect an evaporative emission system pressure pump to

the fuel tank filler tube and pressurize the fuel tank.

• The fuel tank pressure reading should increase.

(7) Disconnect an evaporative emission system pressure pump

and connect hose F.

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

disconnect scan tool MB991502.

Q: Is the fuel tank pressure between

−3.3 and 3.3 kPa (−

0.97 and 0.97 inHg)?
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

). Go to Step 15.

NO : Go to Step 2.

ACX01539

16-PIN

MB991502

AC102602 AC

HOSE F

ACX01358

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DIAGNOSTIC TROUBLE CODE PROCEDURES

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STEP 2. Measure the signal voltage at fuel tank differential
pressure sensor connector G-05.
(1) Tumble the second seat.
(2) Remove the service hole cover (upper) and packing.
(3) Remove the service hole cover (lower) and packing.
(4) Disconnect fuel tank differential pressure sensor connector

G-05.

(5) Connect special tool MB991658 between fuel tank

differential pressure sensor connector G-05 terminals 1, 2
and 3.

(6) Turn the ignition switch to the "ON" position.
(7) Remove the fuel cap.
(8) Measure the voltage between fuel tank differential pressure

sensor connector G-05 terminal 1 and ground.

• The voltage should measure between 2.0 and 3.0 volts.

(9) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 2.0 and 3.0 volts?

YES : Go to Step 10.
NO : Go to Step 3.

STEP 3. Measure the 5-volt reference signal at fuel tank
differential pressure sensor connector G-05.
(1) Disconnect fuel tank differential pressure sensor connector

G-05.

(2) Connect special tool MB991658 between fuel tank

differential pressure sensor connector G-05 terminals 1, 2
and 3.

(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between fuel tank differential pressure

sensor connector G-05 terminal 3 and ground.

• The voltage should measure between 4.8 and 5.2 volts.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.8 and 5.2 volts?

YES : Go to Step 8.
NO : Go to Step 4.

ACX00218

CONNECTOR : G-05

G-05 (B)

SERVICE HOLE (UPPER)

G-05 HARNESS
CONNECTOR:
COMPONENT SIDE

SERVICE HOLE (LOWER)

AC002081AB

MB991658

FUEL TANK DIFFERENTIAL
PRESSURE SENSOR

ACX00218

CONNECTOR : G-05

G-05 (B)

SECOND SEAT UNDER
SERVICE HOLE

G-05 HARNESS
CONNECTOR:
COMPONENT SIDE

AC002081AB

MB991658

FUEL TANK DIFFERENTIAL
PRESSURE SENSOR

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DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-472

STEP 4. Measure the 5-volt reference signal at PCM
connector D-135 by backprobing.
(1) Do not disconnect PCM connector D-135.
(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between PCM connector D-135

terminal 97 and ground by backprobing.

• The voltage should measure between 4.8 and 5.2 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.8 and 5.2 volts?

YES : Go to Step 6.
NO : Go to Step 5.

STEP 5. Check PCM connector D-135 for loose, corroded
or damaged terminals, or terminals pushed back in the
connector.
Q: Are the connector and terminals in good condition?

YES : Go to Step 14.
NO : Repair or replace the faulty component. (Refer to

GROUP 00E, Harness Connector Inspection

P.00E-

). Go to Step 15.

AC203993

CONNECTOR: D-135

D-135 (GR)

PCM

96 97 98 99 100

101 102 103

104

105 106

107 108 109

110 111 112

113 114

115 116 117

118 119 120

AC204160 AB

D-135 HARNESS CONNECTOR:
HARNESS SIDE

AC203997

CONNECTOR: D-135

D-135 (GR)

PCM

D-135 HARNESS CONNECTOR:
HARNESS SIDE

96 97 98 99 100

101 102103

104

105 106

107 108 109

110 111 112

113 114

115 116 117

118 119 120

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