1999 MITSUBISHI LANCER EVOLUTION VI relay

HEATER AND MANUAL AIR CONDITIONER –
Troubleshooting /
On-vehicle Service55-6
INSPECTION AT THE AUTOMATIC COMPRESSOR-ECU TERMINAL
Terminal
No.Check itemChecking requirementsNormal condition
1Output from ECU to A/C compressor
relay
A/C compressor relay: OFFSystem voltage
relay
A/C compressor relay: ON0 V
2Input from A/C switch to ECUA/C switch: OFF0 V
A/C switch: ONSystem voltage
3EarthAlways0 V
ON-VEHICLE SERVICE
REFRIGERANT CHARGING
Caution
The refrigerant generates toxic gases when it is expored
to a heat source such as fire. Keep flames away from
the refrigerant. Perform refrigerant charging at a
well-ventilated place.
1. Recommended charging tools
The following commercially available tools are recommended
for discharging and charging refrigerant.

Gas charging set [No. EA95 (R134a)]

Gas charging set case [No. EA101CS-2]

Gauge manifold [No. EA101N-1]

Charging valve [No. EA108N]

Adapter valve [No. EA104AD-3]
NOTE
The adapter valve opens when the handle is turned
clockwise and closes when it is turned counter-clockwise.

Quick joint (for low pressure) [No. EA413L]

Quick joint (for high pressure) [No. EA413H]

Charging hose (red) [No. EA104N-1]

Charging hose (blue) [No. EA104N-2]

Charging hose (yellow) [No. EA104N-3]

Vacuum pump [No. EA112A]

Vacuum pump adaptor [No. EA112X]
Gauge manifold
Adapter valve
(for low pressure)
Charging hoseVacuum
pump adaptor
Quick joint
(for low pressure)Charging valve
Quick joint
(for high pressure)
Vacuum pump

HEATER AND MANUAL AIR CONDITIONER – On-vehicle Service55-13
DUAL PRESSURE SWITCH SIMPLE CHECK
Measure the high-pressure side pressure. If there is a
continuity between the dual pressure switch terminals with
the dual pressure switch in ON condition as shown in the
graph at left, the switch is in good condition. If not, it is faulty.
Replace the switch.
POWER RELAY CHECK
BLOWER RELAY
Battery voltageTerminal No.
1325
Power is not supplied
Power is supplied
Dual pressure switch
ON
Pressure
196 ± 20 221 2,354 ± 196 2,942 ± 196
OFF
kPa
Blower relay

HEATER AND MANUAL AIR CONDITIONER – On-vehicle Service55-14
A/C COMPRESSOR RELAY, CONDENSER FAN RELAY
Battery voltageTerminal No.
1345
Power is not supplied
Power is supplied
IDLE-UP OPERATION CHECK
1. Before inspection and adjustment, set vehicle in the
pre-inspection condition:
2. Check whether or not the idle speed is the standard value.
Standard value: 700 ± 50 r/min
NOTE
There is no necessity to make an adjustment, because
the idle speed is automatically adjusted by the ISC system.
If, however, there occurs a deviation from the standard
value for some reason, check the fuel control system.
3. When the A/C is running after turning the A/C switch
to ON, check to be sure that the idle speed is at the
standard value.
Standard value: 850 ± 50 r/min
Fan control relay
Compressor
relay
Radiator
fan relay
Condenser
fan relay

FULL-AUTOMATIC AIR CONDITIONER – Troubleshooting55-43
Inspection procedure 2
Air conditioner does not operate.
Probable cause
If the A/C does not operate when the A/C switch is on and the temperature
setting is at 17C, the cause is probably insufficient refrigerant, or a
malfunction of the blower or of the magnet clutch power supply.
Malfunction of blower

Insufficient refrigerant

Malfunction of magnetic clutch

Malfunction of air thermo sensor

Malfunction of A/C compressor relay

Malfunction of refrigerant temperature switch

Malfunction of dual pressure switch

Malfunction of water temperature switch

Malfunction of connector or harness

Malfunction of engine-ECU

Malfunction of A/C-ECU
Does the blower operate?NOInspection procedure 7 (Refer to P.55-45.)
YES
A/C system refrigerant pressure check (Refer to P.55-13.)NGRefill the specified amount of refrigerant. (Refer to P.55-6.)
OK
MUT-II Self-Diag code
Is any of the codes 11, 12, 21 and 22 output?YESINSPECTION CHART FOR DIAGNOSIS CODES (Refer to
P.55-34.)
NO

Magnetic clutch check (Refer to P.55-25.)

A/C compressor relay check (Refer to P.55-14.)

Refrigerant temperature switch check (Refer to P.55-25.)

Dual pressure switch check (Refer to P.55-13.)

Water temperature switch check (Refer to P.55-64.)
<2,000>NG
Replace
OK
Measure at the A/C compressor relay connector A-116X.

Disconnect the connector, and measure at the harness
side connector.
(1) Continuity between terminal (4) and body earth
OK:Continuity
(2) Voltage between terminal (5) and body earth
OK:System voltageOKInspection procedure 13 (Refer to P.55-50.)
(2) NG
Check the following connector:
A-116X
(1) NG
Check the following connectors:
A-116X, A-106NG
Repair
NG
Repair OK
Check the trouble symptom.
NG
Check the harness between the fusible link and the A/C compressor
relay, and repair if necessary.
OK
Check the trouble symptom.
NG
Check the harness between the magnetic clutch and the A/C
compressor relay, and repair if necessary.

FULL-AUTOMATIC AIR CONDITIONER – Troubleshooting55-45
Inspection procedure 7
Blower does not operate.
Probable cause
If no air comes out of the blower even though the blower switch is on, the
cause is probably a malfunction of the blower motor relay circuit.
Malfunction of blower motor relay

Malfunction of blower motor

Malfunction of connector or harness

Malfunction of A/C-ECU
Can an operating sound be heard when the blower speed change-
over switch is operated?NOInspection procedure 15 (Refer to P.55-52.)
YES

Blower motor relay check (Refer to P.55-13.)

Blower motor check (Refer to P.55-21.)NG
Repair
OK
Measure at the blower motor relay connector B-72.

Disconnect the connector, and measure at the harness
side connector.
(1) Continuity between terminal (1) and body earth
OK:Continuity
(2) Voltage between terminal (3) and body earth (Ignition
switch: ON)
OK:System voltage
(3) Voltage between terminal (5) and body earth
OK:System voltage(1) NGCheck the harness between the blower motor relay and the body
earth, and repair if necessary.
(2) NG
Check the harness between the blower motor relay and the ignition
switch, and repair if necessary.
(3) NG
Check the harness between the blower motor relay and the fusible
link No.1, and repair if necessary.
OK
Measure at the blower motor connector B-33.

Disconnect the connector, and measure at the harness
side connector.

Voltage between terminal (1) and body earth (Ignition
switch: ON)
OK:System voltageNGCheck the following connector:
B-76
NG
Repair OK
Check the trouble symptom.
NG
Check the harness between the blower motor relay and the blower
motor, and repair if necessary.
OK
Check the following connector:
B-33NG
Repair
OK
Check the trouble symptom.NGCheck the harness between the blower motor and earth, and
repair if necessary.

FULL-AUTOMATIC AIR CONDITIONER – Troubleshooting55-46
Inspection procedure 8
Blower does not operate in HI mode.
Probable cause
If the blower does not operate in HI mode when the temperature is set to 17 or
32, the cause is probably a malfunction of the blower motor HI relay circuit system.
Malfunction of blower motor HI relay

Malfunction of blower motor

Malfunction of connector or harness

Malfunction of A/C-ECU
NG
Repair OK
Check the trouble symptom.
NG
Check the harness between the blower motor HI relay and the
A/C-ECU, and repair if necessary.
NG
Repair
OK
Check the trouble symptom.
NG
Check the harness between the blower motor HI relay and the
blower motor, and repair if necessary.
OK
Measure at the blower motor HI relay connector B-34.

Disconnect the connector, and measure at the harness
side connector.
(1) Connect terminal (1) to earth.
OK:Blower operates.
(2) Continuity between terminal (3) and body earth
OK:Continuity
(3) Voltage between terminal (4) and body earth (Ignition
switch: ON)
OK:System voltage(1) NGCheck the following connector:
B-34

Blower motor HI relay check (Refer to P.55-57.)

Blower motor check (Refer to P.55-21.)NG
Repair
NG
Repair
OK
Check the trouble symptom.
NG
Check the harness between the blower motor HI relay and the
body earth, and repair if necessary.
(2) NG
Check the following connector:
B-34
NG
Repair
OK
Check the trouble symptom.
NG
Check the harness between the blower motor HI relay and the
junction block, and repair if necessary.
(3) NG
Check the following connector:
B-34
NG
Repair OK
Check the trouble symptom.
YES
Check the following connector:
B-04
OK
Separate A/C-ECU connector B-04 and connect the terminal (12)
of the harness side connector to the earth. Does the blower
operate?NOCheck the following connector:
B-34
NG
Replace the A/C-ECU.

FULL-AUTOMATIC AIR CONDITIONER – Troubleshooting55-50
Inspection procedure 13
Condenser fan does not operate.
Probable cause
If the condenser fan does not turn when the A/C is ON, the cause is probably
a malfunction of the condenser fan motor activation circuit. In this case, reduced
cooling performance will be caused if the vehicle is not running.
Malfunction of condenser fan motor

Malfunction of condenser fan motor relay (HI, LO)

Malfunction of wiring harness or connector
NG
Repair OK
Check the trouble symptom.
NG
Check the harness between the condenser fan motor relay (LO)
and the condenser fan motor, and repair if necessary.
NG
Repair
OK
Check the trouble symptom.
NG
Check the harness between the condenser fan motor relay (LO)
and the body earth, and repair if necessary.
OK
Measure at the condenser fan motor relay (LO) connector A-113X.

Disconnect the connector.
(1) Continuity between terminal (4) and body earth
OK:Continuity
(2) Voltage between terminal (2) and body earth
OK:System voltage
(3) Voltage between terminal (1) and body earth
OK:System voltage(1) NGCheck the following connector:
A-113X
Condenser fan motor check (Refer to P.55-29.)NG
Replace
NG
Repair
OK
Check the trouble symptom.
NG
Check the harness between the condenser fan motor relay (LO)
and the A/C-ECU, and repair if necessary.
(2) NG
Check the following connector:
A-113X
NG
Repair
OK
Check the trouble symptom.
NG
Check the harness between the condenser fan motor relay (LO)
and the fusible link 2, and repair if necessary.
(3) NG
Check the following connector:
A-113X
OK
Continued to the next page
OK
Measure at the condenser fan motor connector A-99.

Disconnect the connector, and measure at the harness
side connector.

Connect the connector A-113X terminal (2) to the battery.

Voltage between terminal (2) and body earth
OK:System voltageNGCheck the following connector:
A-113X
OK
Condenser fan motor relay check (Refer to P.55-14.)NG
Replace

FULL-AUTOMATIC AIR CONDITIONER – Troubleshooting55-51
NG
Repair OK
Check the trouble symptom.
NG
Repair
OK
Check the trouble symptom.
NG
Check the harness between the condenser fan motor relay (HI)
and the engine-ECU, and repair if necessary.
Measure at the radiator fan motor relay (HI) connector A-114X.

Disconnect the connector.
(1) Continuity between 4-B-59 and connector terminal (20)
OK:Continuity
(2) Voltage between terminal (2) and body earth (Ignition
switch: ON)
OK:System voltage
(3) Voltage between terminal (1) and body earth
OK:System voltage(1) NGCheck the following connectors:
A-114X, A-28, B-59
From the previous page
NG
Repair
OK
Check the trouble symptom.
NG
Check the harness between the condenser fan motor relay (HI)
and the ignition switch, and repair if necessary.
(2) NG
Check the following connector:
A-114X
NG
Repair
OK
Check the trouble symptom.
NG
Check the harness between the condenser fan motor relay (HI)
and the fusible link 2, and repair if necessary.
(3) NG
Check the following connector:
A-114X
OK
Measure at the condenser fan motor connector A-99.

Disconnect the connector, and measure at the harness
side connector.

Connect the terminal B-59 to the earth.

Voltage between terminal (1) and body earth (Ignition switch:
ON)
OK:System voltageNOCheck the following connector:
A-112X
NG
Check the harness between the condenser fan motor relay (HI)
and the condenser fan motor, and repair if necessary.
Inspection procedure 14
Rear defogger does not operate.
Probable cause
If the rear defogger does not operate when the rear defogger switch is turned
on (timer operates for 20 minutes), the cause is probably a malfunction of the
A/C-ECU power supply system (earth).
Malfunction of connector or harness

Malfunction of A/C-ECU
Can an operating sound be heard when the rear defogger switch
is operated?NOInspection procedure 15 (Refer to P.55-52.)
YES
Replace the A/C-ECU.