Mitsubishi Space Star. Manual - part 62

MPI  – 

Troubleshooting

13B-35

Code No. P0500 Vehicle speed sensor system

Probable cause

Range of Check



Engine: Two seconds after the engine was started



Idle switch: OFF



Engine speed: 2,500 r/min or more



During high engine load

Set Conditions



The sensor output voltage does not change for 2 seconds (no pulse signal
input).



Malfunction of the vehicle speed sensor



Open or short circuit in the vehicle speed sensor
circuit or loose connector contact



Malfunction of engine-ECU

NO

Check the vehicle speed sensor
(Refer to GROUP 54 – Combination Meter.)

YES

Use an analyzer to measure the output waveform of the
vehicle speed sensor at engine-ECU connector B-31.



Driving the vehicle



The voltage between terminal 86 and earth
OK: A normal waveform should be displayed as de-

scribed in OSCILLOSCOPE INSPECTION PROCE-
DURE, and noise should not be displayed in the
waveform. (Refer to GROUP 23 – Troubleshooting.)

NG

Check the following connectors: B-19, B-31

NG

Repair

OK

Check the harness wire between intermediate connector B-19
and the engine-ECU, and repair if necessary.

OK

Check the following connector: B-31

NG

Repair

OK

Check the trouble symptoms.

NG

Replace the engine-ECU.

Does the speedometer operate normally?

MPI  – 

Troubleshooting

13B-36

Code No. P0505 Idle speed control (ISC) system

Probable cause

Check Area



Vehicle speed has reached 1.5 km/h at least once.



Under the closed loop idle speed control.

Judgment Criteria



Actual idle speed has continued to be higher than the target idle speed by
300 r/min or more for 10 sec.

Check Area



Vehicle speed has reached 1.5 km/h at least once.



During idle speed closed loop control.



The highest temperature at the last drive is 45



C or less.



Engine coolant temperature is approx. 80



C or more.



Battery voltage is 10 V or more.



Intake air temperature is –10



C (14



F) or more.

Judgment Criteria



Actual idle speed has been minimum 200 r/min higher than the target idle
speed for ten seconds.

Check Area



During idle speed closed loop control.



Engine coolant temperature is about 80



C or higher.



Battery voltage is 10 V or higher.



Power steering switch is off.



Intake air pipe pressure is 53 kPa or less.



Intake air temperature is –10



C or more.

Judgment Criteria



Actual idle speed has been minimum 100 r/min higher than the target idle
speed for ten seconds.



Malfunction of idle speed control (ISC) servo



Improper connector contact, open circuit or
short-circuited harness wire



Malfunction of the engine-ECU

MPI  – 

Troubleshooting

13B-37

OK

OK

NG

Repair

Check the harness wire between the engine control relay and
the idle speed control servo, and between the idle speed
control servo and the engine-ECU.

OK

NG

Repair

Check the following connector: B-26, B-28

NG

Repair

OK

Replace the engine-ECU.

NG

Repair

OK

Check the harness wire between the idle speed control servo
and the engine–ECU.

Measure at engine-ECU connector B-28.



Connect the connector using test harness (MB991709),
and measure at pick-up harness.



The voltage between terminal 4 and earth



The voltage between terminal 5 and earth



The voltage between terminal 17 and earth



The voltage between terminal 18 and earth
OK: The voltage changes as follows for three seconds

when the ignition switch is turned ON. 
(When using a circuit tester) 
5 V and 8 V alternates 
(When using an analyzer) 
1 V or less and system voltage alternates

NG

Check the following connector: A-67

OK

OK

Check the harness wire between the engine control relay and
the idle speed control servo, and repair if necessary.

Measure at the idle speed control servo connector A-67.



Disconnect the connector, and measure at the harness
side.



Ignition switch: ON



The voltage between terminal 2 and earth



The voltage between terminal 5 and earth
OK: System voltage

NG

Check the following connector: B-26

OK

OK

NG

Repair

Check the following connector: A-67

OK

NG

Replace

Check the idle speed control (ISC) servo. 
(Refer to P.13B-75*.)

OK

NG

Clean around the throttle valve. (Refer to P.13B-90*.)

Check the throttle body (around the throttle valve) for
contamination.

NO

NG

Repair

Check intake air hose and intake manifold for air intake.

YES

Refer to P.13B-9, INSPECTION CHART FOR DIAGNOSIS
CODES.

Check the trouble symptoms.

OK

Replace the engine-ECU.

MUT-

II

 Self-Diag Code

Is any diagnosis code other than No. P0505 output?

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

NG

NOTE:
*:

Refer to the ’99 SPACE STAR Workshop Manual (Pub. No. CMXE99E1)

MPI  – 

Troubleshooting

13B-38

Cord No. P1610 Immobilizer system

Probable cause

Range of Check



Ignition switch: ON

Set Conditions



Improper communication between the engine-ECU and the immobilizer-ECU



Open or short circuit, or loose connector contact



Malfunction of the immobilizer-ECU



Malfunction of the engine-ECU

NOTE
(1) If the registered ignition keys are close each other when starting the engine, radio interference may

cause this code to be displayed.

(2) This code may be displayed when registering the key ID code.

NG

Replace the engine-ECU.

Check the trouble symptoms.

NG

Replace the immobilizer-ECU.

OK

Check the trouble symptoms.

OK

Check the harness wire between
the immobilizer-ECU and the
engine-ECU.

NG

Replace

Check the following connectors:
B-19, B-30, B-36

NG

Repair