Mitsubishi Lancer Evolution 7. Manual - part 199

MPI -

Troubleshooting

13A-95

Inspection Procedure 28

A/C load signal system

Probable cause

The size of the A/C compressor load is detected according to the difference in

set temperature. When the A/C large load signal is input to the engine-ECU, the

engine-ECU judges that the A/C compressor load is large, and controls the

throttle valve control servo so that the idling speed increases.

D

A/C-ECU malfunction

D

Engine-ECU malfunction

OK

NG

OK

NG

Check the trouble symptoms.

NG

Check the following connector: C-126

Repair

OK

Check the following connector: C-126

Replace the engine-ECU.

Measure at the C-126 engine-ECU

connector.
D

Measure the engine-ECU terminal

voltage.

D

Engine: Idling

D

A/C switch: ON

(A/C compressor driven state)

D

Voltage between terminal No. 24

and earth

D

A/C setting temperature: Minimum

temperature

Air volume: Maximum

Outdoor air sensor ambient

temperature: 18_C or more

OK: 1 V or less

D

A/C setting temperature: indoor

temperature

Air volume: Minimum

OK: System voltage

NG

Repair

NG

NG

Repair

OK

OK

Check the harness between the

engine-ECU and A/C-ECU.
D

Check for short-circuit of the

output cable.

NG

Repair

Check the A/C system.

(Refer to GROUP 55 -

Troubleshooting.)

OK

Intermittent malfunction (Refer to

GROUP 00 - Points to Note for

Intermittent Malfunctions.)

Check the following connectors:

C-16 <manual A/C> ,

C-18 <automatic A/C>, C-20

NG

Repair

OK

OK

Check and repair the harness

between the engine-ECU and

A/C-ECU.
D

Check for disconnection of the

output cable.

Check the following connectors:

C-32 <manual A/C> ,

C-30 <automatic A/C>, C-128 <R.H.

drive vehicles>, C-130 <L.H. drive

vehicles>

Measure at the C-32 A/C-ECU

connector <manual A/C> or C-30

A/C-ECU connector <automatic

A/C>.
D

Measure the A/C-ECU terminal

voltage.

D

Engine: Idling

D

A/C setting temperature: Minimum

temperature

When room temperature is 25_

or more: Max Cool

When room temperature is 25_

or less: Max. Hot

D

A/C switch: ON

D

Voltage between terminal No. 2

and earth <manual A/C (R.H.

drive vehicles)>

D

Voltage between terminal No. 5

and earth <manual A/C (L.H.

drive vehicles)>

D

Voltage between terminal No. 32

and earth <automatic A/C>

OK: System voltage

MPI -

Troubleshooting

13A-96

Inspection Procedure 29

Secondary air control solenoid valve system

Probable cause

The secondary air control solenoid valve switches the pressure led into the

secondary air valve between the intake manifold and the atmospheric pressure.

D

Secondary air control solenoid valve malfunction

D

Engine-ECU malfunction

OK

NG

Replace the engine-ECU.

OK

Intermittent malfunction (Refer to

GROUP 00 - Points to Note for

Intermittent Malfunctions.)

MUT-II Actuator Test
D

No. 36: Secondary air control

solenoid valve

OK: Operation sound is heard,

and there is vibration.

OK

NG

Repair

OK

NG

Intermittent malfunction (Refer to

GROUP 00 - Points to Note for

Intermittent Malfunctions.)

OK

Check the following connector:

B-142

MUT-II Actuator Test
D

No. 36: Secondary air control

solenoid valve

OK: Operation sound is heard,

and there is vibration.

NG

Repair

NG

NG

Repair

OK

Check and repair the harness

between the secondary air control

solenoid valve and engine-ECU.
D

Check for disconnection and

short-circuit of the output cable.

Check the following connectors:

B-14, B-11X

OK

Check the following connector: C-118

Measure at the C-118 engine-ECU

connector.
D

Disconnect the connector to

measure at the haness side.

D

Ignition switch: ON

D

Voltage between terminal No. 53

and earth

OK: System voltage

NG

Replace the secondary air control

solenoid valve.

Measure at the B-142 secondary air

control solenoid valve connector.
D

Disconnect the connector to

measure at the solenoid valve

side.

D

Resistance between terminal No.

1 and terminal No. 2

OK: 29 - 35 Ω (at 20_C)

OK

NG

Measure at the B-142 secondary air

control solenoid valve connector.
D

Disconnect the connector to

measure at the harness side.

D

Ignition switch: ON

D

Voltage between terminal No. 1

and earth

OK: System voltage

OK

NG

Repair

OK

OK

Check and repair the harness between

the secondary air control solenoid

valve and engine control relay.
D

Check for disconnection and

short-circuit of the power cable.

Check the following connectors:

B-14, B-11X

NG

Repair

Check the harness between the

secondary air control solenoid valve

and engine control relay.
D

Check for damage of the power

cable.

NG

Repair

OK

Check the harness between the

secondary air control solenoid valve

and engine-ECU.
D

Check for damage of the output

cable.

MPI -

Troubleshooting

13A-97

Inspection Procedure 30

Intercooler water spray circuit system

Probable cause

D

When the intercooler water spray switch (manual) turns ON, the intercooler

water spray manual ON signal is input to the engine-ECU. After receiving

this signal, the engine-ECU turns the intercooler water spray relay ON. The

intercooler water spray motor is driven to inject the water for air cooling into

the intercooler and increase the filling performance.

D

When the intercooler water spray switch (automatic) turns ON, the intercooler

water spray automatic ON signal is input to the engine-ECU. After receiving

this signal, the engine-ECU turns the intercooler water spray relay ON

intermittently during high-load operation. The intercooler water spray motor is

driven to inject the water for air cooling into the intercooler and increase the

filling performance.

D

Intercooler water spray switch malfunction

D

Intercooler water spray relay malfunction

D

Intercooler water spray motor malfunction

D

Intercooler water spray relay circuit disconnection,

short-circuit, or connector contact defect

D

Intercooler water spray switch circuit disconnection,

short-circuit, or connector contact defect

D

Ignition switch malfunction

D

Engine-ECU malfunction

NG

Repair

OK

Replace the engine-ECU.

OK

NG

OK

NG

Repair

OK

Check the following connector: D-34

Check the intercooler water spray

switch. (Refer to GROUP 15 -

Intake and Exhaust.)

Check the intercooler water spray

injection.
D

Ignition switch: ON

D

Intercooler water spray switch

(manual): ON

OK: The intercooler water spray

injects water.

NG

Repair

OK

Measure at the D-34 intercooler

water spray switch connector.
D

Disconnect the connector to

measure at the harness side.

D

Ignition switch: ON

D

Voltage between terminal No. 5

and earth

OK: System voltage

NG

OK

Check the harness between the

engine-ECU and intercooler water

spray switch.
D

Check for disconnection and

short-circuit of the signal cable.

Repair

Intermittent malfunction (Refer to

GROUP 00 - Points to Note for

Intermittent Malfunctions.)

NG

OK

Check the harness between the

intercooler water spray switch and

engine-ECU.
D

Check for damage of the earth

cable.

Repair

NG

Repair

OK

Replace the engine-ECU.

OK

NG

OK

NG

Repair

OK

Check the following connector: D-34

Check the intercooler water spray

switch. (Refer to GROUP 15 -

Intake and Exhaust.)

Check the intercooler water spray

injection.
D

Disconnect the C-118

engine-ECU connector, and earth

the terminal No. 55.

D

Ignition switch: ON

OK: The intercooler water spray

injects water.

NG

Repair

OK

Measure at the D-34 intercooler

water spray switch connector.
D

Disconnect the connector to

measure at the harness side.

D

Ignition switch: ON

D

Voltage between terminal No. 3,

terminal No. 5 and earth

OK: System voltage

NG

OK

Check the harness between the

engine-ECU and intercooler water

spray switch.
D

Check for disconnection and

short-circuit of the signal cable.

Repair

Check and repair the harness

between the intercooler water spray

switch and engine-ECU.
D

Check for damage of the signal

cable.

NG

OK

Check the harness between the

intercooler water spray switch and

earth.
D

Check for disconnection and

damage of the earth cable.

Repair

NG

Repair

OK

Check the following connector: C-08

OK

Check the following connector:

C-222

NG

Repair

OK

To the next page

NG

Replace the intercooler water spray

relay.

Check the intercooler water spray

relay. (Refer to GROUP 15 - Intake

and Exhaust.)

NG

Check the following connectors:

C-122, C-130

Check the following connectors:

C-115, C-122, C-130

NG

MPI -

Troubleshooting

13A-98

OK

NG

OK

Check the harness between the

intercooler water spray relay and

ignition switch.
D

Check for damage of the power

cable.

Repair

OK

OK

Check the following connector: C-135

NG

Repair

NG

NG

OK

Measure at the C-118 engine-ECU

connector.
D

Disconnect the connector to

measure at the harness side.

D

Voltage between terminal No. 55

and earth

(Ignition switch: ON)

OK: System voltage

OK

Check the following connectors:

C-130, C-208, C-222

NG

NG

OK

Measure at the C-222 intercooler water

spray relay connector.
D

Disconnect the connector to

measure at the harness side.

D

Voltage between terminal No. 3,

terminal No. 1 and earth

(Ignition switch: ON)

OK: System voltage

Form the previous page

OK

Repair

Check the harness between the

intercooler water spray relay and

intercooler water spray motor.
D

Check for disconnection,

short-circuit and damage of the

power cable.

Check the following connectors:

C-209, C-210, C-201, C-208, C-102

<L.H. drive vehicles>

NG

Repair

Replace the engine-ECU.

OK

Check the following connectors:

C-209, C-210, C-201, C-208, C-102

<L.H. drive vehicles>

NG

Repair

OK

Check and repair the harness

between the intercooler water spray

relay and engine-ECU.
D

Check for disconnection and

short-circuit of the signal cable.

OK

Check the ignition switch. (Refer to

GROUP 54.)

Check the harness between the

intercooler water spray relay and

ignition switch.
D

Check for disconnection and

short-circuit of the power cable.

Repair

NG

OK

Check the harness between the

intercooler water spray motor and

earth.
D

Check for disconnection and

damage of the earth cable.

Repair

OK

Check the following connectors:

C-118, C-130

NG

Repair

NG

OK

Check and repair the harness between

the intercooler water spray relay and

engine-ECU.
D

Check for damage of the signal

cable.

Repair

OK

Check the following connector: A-44

NG

Repair

OK

Check the intercooler water spray

motor. (Refer to GROUP 15 - Intake

and Exhaust.)

Repair

NG