Mitsubishi Space Star. Manual - part 55

MPI  – 

Troubleshooting

13B-7

FREEZE FRAME DATA

When the engine-ECU detects a malfunction and stores a
diagnosis code, it also stores a current status of the engine.
This function is called  “freeze frame data.” By analyzing this
“freeze frame” data with the MUT-

II

, an effective

troubleshooting can be performed.

Displayed items of freeze frame data are shown in the following:

DISPLAYED ITEM LIST

Data item

Unit

Engine coolant temperature sensor



C

Engine speed

r/min

Vehicle speed

km/h

Long-term fuel compensation (long-term
fuel trim)

%

Short-term fuel compensation (short-term
fuel trim)

%

Fuel control condi-
tion

Open loop

OL

tion

Closed loop

CL

Open loop owing to
drive condition

OL-DRV.

Open loop owing to
system malfunction

OL-SYS.

Closed loop based
on one oxygen sen-
sor

CL-H02S

Calculation load value

%

Diagnosis code during data recording

–

NOTE
If malfunctions have been detected in multiple systems, store
one malfunction only, which has been detected first.

READINESS TEST STATUS

The engine-ECU monitors the following main diagnosis items,
judges if these items are in good condition or not, and the
stores its history.  This history can be read out by using MUT-

II

.

(If the ECU has judged a item before, the MUT-

II

 displays

“Complete.”)
In addition, if diagnosis codes are erased or the battery  cable
is disconnected, this history will also be erased (the memory
will be reset).



Catalyst: P0421



Oxygen sensor: P0130



Oxygen sensor heater: P0135, P0141

MPI  – 

Troubleshooting

13B-8

FAIL-SAFE FUNCTION REFERENCE TABLE

When the main sensor malfunctions are detected by the diagnosis function, the vehicle is controlled by
means of the pre-set control logic to maintain safe conditions for driving.

Malfunctioning item

Control contents during malfunction

Vacuum sensor

1.

Uses the throttle position sensor signal and engine speed signal (crank angle sensor
signal) to take reading of the basic injector drive time and basic ignition timing from
the pre-set mapping.

2.

Fixes the ISC servo in the appointed position so idle control is not performed.

Intake air temperature
sensor

Controls as if the intake air temperature is 45



C.

Throttle position sen-
sor (TPS)

No increase in fuel injection amount during acceleration due to the throttle position sensor
signal.

Engine coolant tem-
perature sensor

Controls as if the engine coolant temperature is 80



C.

Camshaft position sen-
sor

Injects fuel into the cylinders in the order 1-3-4-2 with irregular timing. (After the ignition switch
is turned to ON, the No. 1 cylinder top dead centre is not detected at all.)

Detonation sensor

Switches the ignition timing from ignition timing for super petrol to ignition timing for standard
petrol.

Oxygen sensor (front)

Air/fuel ratio feedback control (closed loop control) is not performed.

Oxygen sensor (rear)

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

Misfire detection

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

MPI  – 

Troubleshooting

13B-9

INSPECTION CHART FOR DIAGNOSIS CODES

Code No.

Diagnosis item

Reference page

P0105

Vacuum sensor system

13B-10

P0110

Intake air temperature sensor system

13B-12

P0115

Engine coolant temperature sensor system

13B-13

P0120

Throttle position sensor system

13B-16

P0125

Feedback system

13B-18

P0130

Oxygen sensor (front) system <sensor 1>

13B-19

P0135

Oxygen sensor heater (front) system <sensor 1>

13B-21

P0136

Oxygen sensor (rear) system <sensor 2>

13B-22

P0141

Oxygen sensor heater (rear) system <sensor 2>

13B-24

P0170

Abnormal fuel system

13B-25

P0201

No. 1 injector system

13B-26

P0202

No. 2 injector system

13B-26

P0203

No. 3 injector system

13B-26

P0204

No. 4 injector system

13B-26

P0300



Random cylinder misfire detected

13B-27

P0301

No. 1 cylinder misfire detected

13B-28

P0302

No. 2 cylinder misfire detected

13B-28

P0303

No. 3 cylinder misfire detected

13B-28

P0304

No. 4 cylinder misfire detected

13B-28

P0325

Detonation sensor system

13B-29

P0335

Crank angle sensor system

13B-25

P0340

Camshaft position sensor system

13B-31

P0403

EGR control solenoid valve system

13B-32

P0421

Catalyst malfunction

13B-33

P0443

Purge control solenoid valve system

13B-34

P0500

Vehicle speed sensor system

13B-35

P0505

Idle speed control system

13B-36

P1610

Immobilizer system

13B-38

NOTE
1.

Do not replace the engine-ECU until a through terminal check reveals there are no short/open circuit.

2.

Check that the engine-ECU earth circuit is normal before checking for the cause of the problem.

3.

After the engine-ECU has detected a malfunction, a diagnosis code is recorded the next time the
engine is started and the same malfunction is re-detected. However, for items marked with a “



”,

the diagnosis code is recorded on the first detection of the malfunction.

4.

Sensor 1 indicates the sensor mounted at a position closest to the engine, and sensor 2 indicates
the sensor mounted at the position second closest to the engine.

MPI  – 

Troubleshooting

13B-10

INSPECTION PROCEDURE CLASSIFIED BY DIAGNOSIS CODE

Code No. P0105 Vacuum sensor system

Range of Check

Range of Check



Ignition switch: ON

Set Conditions



The output voltage of the vacuum sensor is 4.5 V or more for 2 seconds. 
(This corresponds to the absolute manifold pressure of 115 kPa or more.)



Malfunction of the vacuum sensor



Improper connector contact, open circuit or
short-circuited harness



Malfunction of the engine-ECU

Range of Check



The output voltage of the throttle position sensor is 1.25 V or more.

or



The vehicle is stationary.

Set Conditions



The output voltage of the vacuum sensor is 0.2 V or less for 2 seconds. 
(This corresponds to the absolute manifold pressure of 4.9 kPa or less.)

OK

To the next page

OK

Check the harness between the
vacuum sensor and the
engine-ECU, and repair if necessary.

NG

Check the following connector:
B-31

NG

Repair

Check the trouble symptoms.

OK

Check the harness between the
vacuum sensor and the
engine-ECU, and repair if necessary.

OK

Check the trouble symptoms.

NG

Replace the engine-ECU.

(2) NG

Check the following connector:
B-31

NG

Repair

OK

Check the harness between the
vacuum sensor and the
engine-ECU, and repair if necessary.

MUT-

II

 Data list

32 Barometric pressure sensor

(Refer to P.13B-65, DATA LIST
REFERENCE TABLE.)

OK

Transient malfunction
(Refer to GROUP 00 – Points to
Note for Intermittent Malfunctions.)

NG

NG

Repair

OK

Measure at vacuum sensor
connector A-95.



Disconnect the connector and
measure at the harness side.

(1) Voltage between terminal 2 and

earth (Ignition switch: ON)
OK: 4.8  – 5.2 V

(2) Resistance between terminal 3

and earth
OK: 2 

Ω

 or less

(1) NG

Measure at engine-ECU connector
B-31.



Measure the voltage at the
engine-ECU terminal.



Ignition switch: ON



Voltage between terminal 81 and
earth
OK: 4.8  – 5.2 V

OK

Check the following connector:
B-31

NG

Repair

NG

Check the following connector:
B-31

NG

Repair

OK

Check the harness between the
vacuum sensor and the engine-ECU.

NG

Repair

OK

Check the trouble symptoms.

NG

Replace the engine-ECU.

OK

Measure at vacuum sensor
connector A-95.



Connect connector terminals
No.1, No.2 and No.5 only by
using test harness (MB991348),
and measure at the pick-up
harness.



Ignition switch: ON

(1) Voltage between terminal 2 and

earth
OK: 4.8  – 5.2 V

(2) Voltage between terminal 4 and

earth
OK: Altitude 0 m: 3.7 – 4.3 V

Altitude 1200 m: 
3.2  – 3.8 V

(3) Voltage between terminal 3 and

earth
OK: 0.5 V or less

(1) NG

Check the following connector:
B-31

NG

Repair

(3) NG

(2) NG

Replace the vacuum sensor.

OK

Check the harness between the
vacuum sensor and the engine-ECU.

NG

Repair

Check the following connector:
A-95