Mitsubishi Lancer Evolution VI. Manual - part 33

MPI  – 

Troubleshooting

13-20

INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS

INSPECTION PROCEDURE 1

Communication with MUT-

II

 is impossible.

(Communication with all systems is impossible.)

Probable cause

The cause is probably a defect in the power supply system (including earth) for the
diagnosis line.

D

Malfunction of the diagnosis connector

D

Malfunction of the harness wire

Measure at the diagnostic connector
B-22.

D

Voltage between 16 and earth
OK: System voltage

NG

Check the following connectors:
<EVOLUTION-IV> B-49, B-75, B-73
<EVOLUTION-V, VI> B-73, B-80

NG

Repair

OK

Check trouble symptom.

NG

Check the harness wire between the
power supply and diagnostic connector,
and repair if necessary.

OK

Measure at the diagnostic connector
B-22.

D

Continuity between 4 and earth

D

Continuity between 5 and earth
OK: Continuity

NG

Check the earth wire, and repair if nec-
essary.

OK

Replace the MUT-

II

.

INSPECTION PROCEDURE 2

MUT-

II

 communication with engine-ECU is impossible.

Probable cause

One of the following causes may be suspected.

D

No power supply to engine-ECU.

D

Defective earth circuit of engine-ECU.

D

Defective engine-ECU.

D

Improper communication line between engine-ECU and MUT-

II

D

Malfunction of engine-ECU power supply circuit

D

Malfunction of engine-ECU

D

Open circuit between immobilizer-ECU and diagnosis
connector

OK

Check the engine-ECU power supply and earth circuit. 
(Refer to P.13-53, INSPECTION PROCEDURE 45.)

NG

Check the harness wire between engine-ECU and diagnosis con-
nector.

NG

Repair

OK

Check trouble symptom.

Check the following connectors:
B-22, B-65, B-32, B-61

NG

Repair

MPI  – 

Troubleshooting

13-21

INSPECTION PROCEDURE 3

The engine warning lamp does not illuminate right after
the ignition switch is turned to the ON position.

Probable cause

For checking for burnt-out bulb, the engine-ECU causes the engine warning lamp
to illuminate for five seconds immediately after the ignition switch is turned to ON.
If the engine warning lamp does not illuminate immediately after the ignition switch
is turned to ON, one of the malfunctions listed at right has probably occurred.

D

Burnt-out bulb of the engine warning lamp

D

Defective engine warning lamp circuit

D

Malfunction of the engine-ECU

MUT-

II

 Data list

16 engine-ECU power supply voltage (Refer to P.13-57)

NG

Check the engine-ECU power supply and earth circuit.
(Refer to P.13-53, INSPECTION PROCEDURE 45.)

OK

Measure at the engine-ECU connector B-60.

D

Disconnect the connector, and measure at the harness side.

D

Earth the terminal No.36. (Ignition switch: ON)
OK: The engine warning lamp illuminates.

OK

Check the following
connector: B-60

NG

Repair

OK

Check trouble symptom.

NG

Replace the engine-ECU.

NG

Check for burnt-out bulb.

NG

Replace

OK

Measure at the combination meter connector B-08.

D

Disconnect the connector, and measure at the harness side.

D

Voltage between 42 and earth (Ignition switch: ON)
OK: System voltage

NG

Check the engine warning lamp power supply circuit, and repair
if necessary.

OK

Check the following connectors:
B-08, B-65, B-60

NG

Repair

OK

Check trouble symptom.

NG

Check the harness wire between combination meter and engine-
ECU connector, and repair if necessary.

INSPECTION PROCEDURE 4

The engine warning lamp remains illuminating and never
goes out.

Probable cause

In cases such as the above, the cause is probably that the engine-ECU is detecting
a problem in a sensor or actuator, or that one of the malfunctions listed at right has
occurred.

D

Short-circuit between the engine warning lamp and
engine-ECU

D

Malfunction of the engine-ECU

MUT-

II

 Self-Diag code

Are diagnosis codes displayed?

Yes

Refer to P.13-8, INSPECTION CHART FOR DIAGNOSIS CODES.

No

Measure at the combination meter connector B-08.

D

Disconnect the connector, and measure at the harness side.

D

Disconnect the engine-ECU connector

D

Continuity between 53 and earth
OK: No continuity

NG

Check the harness wire between combination meter and engine-
ECU connector, and repair if necessary.

OK

Replace the engine-ECU.

MPI  – 

Troubleshooting

13-22

INSPECTION PROCEDURE 5

No initial combustion (starting impossible)

Probable cause

In cases such as the above, the cause is probably that a spark plug is defective,
or that the supply of fuel to the combustion chamber is defective.
In addition, foreign materials (water, kerosene, etc.) may be mixed with the fuel.

D

Malfunction of the ignition system

D

Malfunction of the fuel pump system

D

Malfunction of the injectors

D

Malfunction of the engine-ECU

D

Foreign materials in fuel

Check system voltage when cranking.

OK: 8 V or higher

NG

Check the battery.

OK

MUT-

II

: Inspection of no initial combustion. 

(Refer to P.13-47, INSPECTION PROCEDURE 37.)

OK

Can any sound be heard from the injectors when cranking (check
using a soundscope)?

NG

Check the injector system. (Refer to P.13-15, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)

OK

Ignition system: Inspection of no initial combustion. 
(Refer to P.13-47, INSPECTION PROCEDURE 38.)

OK

Check the following items.

D

Check the ignition coil, spark plugs, spark plug cables.

D

Check if the injectors are clogged.

D

Check if foreign materials (water, alcohol, etc.) got into fuel.

D

Check the compression pressure.

MPI  – 

Troubleshooting

13-23

INSPECTION PROCEDURE 6

Initial combustion but no complete combustion
(starting impossible)

Probable cause

In such cases as the above, the cause is probably that the spark plugs are generating
sparks but the sparks are weak, or the initial mixture for starting is not appropriate.

D

Malfunction of the ignition system

D

Malfunction of the injector system

D

Foreign materials in fuel

D

Poor compression

D

Malfunction of the engine-ECU

Check system voltage when cranking.

OK: 8 V or higher

NG

Check the battery.

OK

MUT-

II

: Check if uncompleted combustion occurs. 

(Refer to P.13-48, INSPECTION PROCEDURE 39.)

OK

Can any sound be heard from the injectors when cranking (check
using a soundscope)?

NG

Check the injector system, (Refer to P.13-15, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)

OK

Is starting good if the engine is cranked with the accelerator pedal
slightly depressed?

Yes

Check ISC servo for op-
eration sound. 

NG

Check the ISC servo sys-
tem. (Refer to P.13-44, IN-
SPECTION PROCE-
DURE 33.)

OK

D

Clean the throttle valve area.

D

Adjust the fixed SAS. (Refer to P.13-30.)*

No

Check the ignition timing when cranking.

OK: Approx. 5

_

BTDC

NG

Check that the crank angle sensor and the timing belt cover are
installed properly.

OK

Check the following items.

D

Check the ignition coil, spark plugs, spark plug cables.

D

Check the injectors for clogging and leakage.

D

Check the compression pressure.

D

Check fuel lines for clogging.

D

Check if foreign materials (water, alcohol, etc.) got into fuel.

NOTE
*:

Refer to Workshop Manual for LANCER EVOLUTION-IV and EVOLUTION-V (Pub. No. S9806CNCP9).