Mitsubishi Montero (2004+). Manual - part 134

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-23

PROCEDURE 6

OTHER MONITOR (Main components, sensors and switches, wire breakage and short circuit)
DTC

• Main components: P0134, P0154, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0506, 

P0507, P1400

• Sensors and switches: P0101, P0102, P0106, P0107, P0108, P0111, P0112, P0113, P0116, 

P0117, P0118, P0122, P0123, P0125, P0181, P0182, P0183, P0335, P0340, P0461

• Wire breakage and short circuit: P0130, P0131, P0132, P0135, P0136, P0137, P0138, P0141, 

P0150, P0151, P0152, P0155, P0156, P0157, P0158, P0161, P0201, P0202, P0203, P0204, 
P0205, P0206, P0403, P0443, P0446

Drive cycle 
pattern

This monitor [from start to ignition switch "LOCK" (OFF) position] will be completed while driving the 
vehicle with the following drive cycle pattern. It will take 10 minutes. You must complete this drive 
twice.
NOTE: Drive according to the graph below.

Inspection 
conditions

• Engine coolant temperature: 80°C (176°F) or more

• Atmospheric temperature: 5°C (41°F) or more

• Condition of A/T: Selector lever D range

Test procedure

1. Engine: start
2. Accelerate until the vehicle speed is 56 

− 64 km/h (35 − 40 mph), and travel for 300 seconds or 

more. 

3. Return the vehicle to the shop. 
4. After stopping the vehicle, continue idling for 300 seconds, and then turn the ignition switch to the 

"LOCK" (OFF) position. Moreover, the vehicle should be set to the following conditions for idling.
NOTE: Vehicles for Canada, the headlight, taillight, etc. remain lit even when the lighting switch is 
in "OFF" position but this is no problem for checks.
• A/C switch: OFF

• Lights and all accessories: OFF

• Transmission: P range

• Steering wheel: Straightforward position

5. Confirm that the diagnostic trouble code (DTC) is not output.
6. If a DTC is displayed, refer to Diagnostic Trouble Code Chart 

P.13A-26

.

AKX01350

AKX01350

(3)

(2)

(1)

(4)

300 SECONDS OR MORE
56 - 64 km/h (35 - 40 mph)

ENGINE: IDLING
TRANSMISSION: NEUTRAL
300 SECONDS

ENGINE START

IGNITION 
SWITCH:"LOCK" 
(OFF)

64
(40)

32
(20)

0

100

50

0

VEHICLE 
SPEED
km/h (mph)

AKX01350 AB

CALCULATED
LOAD (%)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-24

SYSTEM READINESS TEST STATUS

.

PURPOSE
The Readiness function (also referred as I/M Readi-
ness or I/M Flags) indicates if a full diagnostic check 
has been "Completed" (is "Ready") for each 
non-continuous monitor. Enhanced I/M State Emis-
sion Programs will use the Readiness status (Codes) 
to see if the vehicle is ready for OBD-II testing. 
"Incomplete" (Not Ready) codes will be one of the 
triggers for I/M failure.

.

OVERVIEW
The PCM monitors the following main diagnosis 
items and records whether the evaluation was com-
pleted or is incomplete. The Readiness codes were 
established for the I/M programs, thereby confirming 
that the vehicle was not tampered with by erasing the 
diagnostic trouble code(s) (DTC's) before I/M testing. 
The Readiness and DTC codes can be reset by dis-
connecting the battery or by erasing the codes with a 
scan tool. For this reason all Readiness codes must 
read "Complete" before I/M testing.
When the monitors run and complete, the scan tool 
MB991958 (MUT-III Sub Assembly) will record the 
Readiness Code as " Complete " (General Scan 
Tools record as " Ready "). When the vehicle is oper-
ating normally and the OBD-II Drive Cycle is carried 

out, Readiness Code will set as " Complete " on the 
first drive cycle. If during the first drive cycle a fault is 
detected then, a second drive is required before the 
Readiness Code will " Complete. " If the fault is still 
there, then a DTC will set.

• Catalyst: P0421, P0431

• Evaporative system: P0441, P0442, P0455, 

P0456

• Heated oxygen sensor: P0130, P0131, P0132, 

P0133, P0134, P0136, P0137, P0138, P0139, 
P0150, P0151, P0152, P0153, P0154, P0156, 
P0157, P0158, P0159

• Heated oxygen sensor heater: P0135, P0141, 

P0155, P0161

• EGR system: P0401

After the Readiness is "Complete," the technician is 
assured that any DTC's associated with that monitor 
will be displayed if the system has a problem. That is 
why some State's I/M programs require the Readi-
ness Code as "Complete" before they check for 
DTC's. 
NOTE: After a repair is mode for a DTC the techni-
cian should drive the OBD-II drive cycle checking 
that the scan tool MB991958 (MUT-III Sub Assem-
bly) records all Readiness as "Complete".

FAIL-SAFE FUNCTION REFERENCE TABLE

M1131153000318

When the main sensor malfunctions are detected by 
the diagnostic test mode, the vehicle is controlled by 
means of the following defaults.

MALFUNCTION ITEM

CONTROL CONTENTS DURING MALFUNCTION

Volume airflow sensor

• Uses the throttle position sensor signal and engine speed signal (crankshaft 

position sensor signal) for basic injector drive time and basic ignition timing 
from the pre-set mapping.

• Fixes the IAC motor in the appointed position so idle air control is not 

performed.

Intake air temperature 
sensor

Controls as if the intake air temperature is 25

°C (77°F).

Engine coolant 
temperature sensor

Controls as if the engine coolant temperature is 80

°C (176°F). (This control will 

be continued until the ignition switch is turned to " LOCK " (OFF) position even 
though the sensor signal returns to normal.)

Camshaft position sensor Injects fuel simultaneously into all cylinders. (After the ignition switch is turned to 

" ON " position, the No.1 cylinder top dead center is not detected at all.)

Barometric pressure 
sensor

Controls as if the barometric pressure is 101 kPa (30 in.Hg).

Knock sensor

Switches the ignition timing from ignition timing for high octane to ignition timing 
for standard octane fuel.

Heated oxygen sensor 
<front>

Air/fuel ratio closed loop control is not performed.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-25

Heated oxygen sensor 
<rear>

Performs the closed loop control of the air/fuel ratio by using only the signal of 
the heated oxygen sensor (front) installed on the front side of the catalytic 
converter.

Misfire detection

The PCM stops supplying fuel to the cylinder with the highest misfiring rate if a 
misfiring that could damage the catalytic converter is detected.

Accelerator pedal position 
sensor (main)

• Detects the amount of the accelerator pedal travel through the use of the 

accelerator pedal position sensor (sub) signal, but rendering it only as being 
approximately one-half the normal opening angle.

• Prohibits the operation of the auto-cruise control.  

• Cuts off fuel when the engine speed exceeds 3,000 r/min.

• Suppresses the engine output by stopping the electronically controlled 

throttle valve system if the accelerator pedal position sensor (sub) is also 
malfunctioning.

Accelerator pedal position 
sensor (sub)

• Detects the amount of the accelerator pedal travel through the use of the 

accelerator pedal position sensor (main) signal, but rendering it only as being 
approximately one-half the normal opening angle.

• Prohibits the operation of the auto-cruise control.

• Cuts off fuel when the engine speed exceeds 3,000 r/min.

• Suppresses the engine output by stopping the electronically controlled 

throttle valve system if the accelerator pedal position sensor (main) is also 
malfunctioning.

Throttle position sensor 
(main)

• Controls the throttle valve position through the use of the throttle position 

sensor (sub) signal.

• Renders the amount of accelerator pedal travel as being approximately 

one-half the normal opening angle.

• Prohibits the operation of the engine speed feedback control.

• Prohibits the operation of the auto-cruise control.

• Cuts off fuel when the engine speed exceeds 3,000 r/min.

• Suppresses the engine output by stopping the electronically controlled 

throttle valve system if the throttle position sensor (sub) is also 
malfunctioning.

Throttle position sensor 
(sub)

• Controls the throttle valve position through the use of the throttle position 

sensor (main) signal.

• Renders the amount of accelerator pedal travel as being approximately 

one-half the normal opening angle.

• Prohibits the operation of the auto-cruise control.

• Cuts off fuel when the engine speed exceeds 3,000 r/min.

• Prohibits the idle speed control from learning.

• Suppresses the engine output by stopping the electronically controlled 

throttle valve system if the throttle position sensor (main) is also 
malfunctioning.

Throttle valve position 
feedback.

• Suppresses the engine output by stopping the electronically controlled 

throttle valve system.

• Prohibits the operation of the auto-cruise control.

• Prohibits the operation of the engine speed feedback control.

MALFUNCTION ITEM

CONTROL CONTENTS DURING MALFUNCTION

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-26

DIAGNOSTIC TROUBLE CODE CHART

M1131151000765

Throttle actuator control 
motor.

• Suppresses the engine output by stopping the electronically controlled 

throttle valve system.

• Prohibits the operation of the auto-cruise control.

• Prohibits the operation of the engine speed feedback control.

Throttle actuator control 
computer.

• Suppresses the engine output by stopping the electronically controlled 

throttle valve system.

• Prohibits the operation of the auto-cruise control.

• Prohibits the operation of the engine speed feedback control.

Communication between 
throttle actuator control 
computer and engine 
control computer

• Renders the amount of accelerator pedal travel as being approximately 

one-half the normal opening angle.

• Prohibits the operation of the auto-cruise control.

• Prohibits the operation of the engine speed feedback control.

• Cuts off fuel when the engine speed exceeds 3,000 r/min.

MALFUNCTION ITEM

CONTROL CONTENTS DURING MALFUNCTION

DTC NO.

DIAGNOSTIC ITEM

REFERENCE 
PAGE

P0101*

Volume airflow circuit range/performance problem

P.13A-33

P0102*

Volume airflow circuit low input

P.13A-42

P0106

Manifold absolute pressure circuit range/performance problem

P.13A-51

P0107

Manifold absolute pressure circuit low input

P.13A-68

P0108

Manifold absolute pressure circuit high input

P.13A-84

P0111*

Intake air temperature circuit range/performance problem

P.13A-95

P0112*

Intake air temperature circuit low input

P.13A-102

P0113*

Intake air temperature circuit high input

P.13A-107

P0116*

Engine coolant temperature circuit range/performance problem

P.13A-114

P0117*

Engine coolant temperature circuit low input

P.13A-125

P0118*

Engine coolant temperature circuit high input

P.13A-130

P0122*

Throttle position sensor (main) circuit low input

P.13A-138

P0123*

Throttle position sensor (main) circuit high input

P.13A-147

P0125*

Insufficient coolant temperature for closed loop fuel control

P.13A-154

P0128

Coolant thermostat (coolant temperature below thermostat regulating 
temperature)

P.13A-165

P0130

Heated oxygen sensor circuit (bank 1 sensor 1)

P.13A-167

P0131

Heated oxygen sensor circuit low voltage (bank 1 sensor 1)

P.13A-184

P0132

Heated oxygen sensor circuit high voltage (bank 1 sensor 1) 

P.13A-191

P0133

Heated oxygen sensor circuit slow response (bank 1 sensor 1) 

P.13A-196

P0134*

Heated oxygen sensor circuit no activity detected (bank 1 sensor 1) 

P.13A-202

P0135

Heated oxygen sensor heater circuit (bank 1 sensor 1)

P.13A-211

P0136

Heated oxygen sensor circuit (bank 1 sensor 2)

P.13A-222

P0137

Heated oxygen sensor circuit low voltage (bank 1 sensor 2) 

P.13A-238