1999 MITSUBISHI LANCER EVOLUTION VI sensor

HEATER AND MANUAL AIR CONDITIONER – Troubleshooting55-5
No.Trouble symp-
tomProblem causeRemedyRefer-
ence
page
1When the igni-
tion switch is
“ON”, the A/C
does not oper
Refrigerant leak or overfilling of refriger-
antReplenish the refrigerant, repair the
leak or take out some of the
refrigerant55-6
does not oper-
ate.A/C compressor relay is defectiveReplace the A/C compressor relay55-14ate.
A/C compressor magnetic clutch is
defectiveReplace the A/C compressor magnet
clutch55-26
Dual pressure switch is defectiveReplace the dual pressure switch55-13
A/C switch is defectiveReplace the A/C switch55-17
Blower switch is defectiveReplace the blower switch55-17
Air thermo-sensor is defectiveReplace the air thermo-sensor55-22
Refrigerant temperature switch is defec-
tiveReplace the refrigerant temperature
switch55-25
Automatic compressor-ECU is defectiveReplace the automatic compressor-
ECU–
2When the A/C is
operating, tem-
perat re inside
Refrigerant leakReplenish the refrigerant and repair
the leak55-6
perature inside
the
passengerDual pressure switch is defectiveReplace the dual pressure switch55-13the passenger
compartment
doesn’tde-Air thermo-sensor is defectiveReplace the air thermo-sensor–doesnt de-
crease (cool air
is not emitted)
Condenser fan relay is defectiveReplace the condenser fan relay55-14
is not emitted).Condenser fan motor is defectiveReplace the condenser fan motor55-29
Radiator fan relay (HI, LO) is defectiveReplace the radiator fan relay (HI, LO)55-14
Radiator fan motor is defectiveReplace the radiator fan motor–
Refrigerant temperature switch is defec-
tiveReplace the refrigerant temperature
switch55-25
Automatic compressor-ECU is defectiveReplace the automatic compressor-
ECU–
3Blower fan mo-
tor doesn’t turn
Blower switch is defectiveReplace the blower switch55-17
tor doesn’t turn.Blower relay is defectiveReplace the blower relay55-13
Resistor is defectiveReplace the resistor55-21
Blower fan motor is defectiveReplace the blower fan motor55-21
4Blower fan mo-
tor doesn’t stop
t rning
Defective harness between the blower
fan motor and the blower switchRepair the harness–
turning.Blower switch is defectiveReplace the blower switch55-17
Resistor is defectiveReplace the resistor55-21
5When the A/C is
operating con
Condenser fan relay is defectiveReplace the condenser fan relay55-14
operating con-
denser fan orCondenser fan motor is defectiveReplace the condenser fan motor55-29denser an or
radiator fan
does not runRadiator fan relay (HI, LO) is defectiveReplace the radiator fan relay (HI, LO)55-14does not run.
Radiator fan motor is defectiveReplace the radiator fan motor–
Dual pressure switch is defectiveReplace the dual pressure switch55-13
Engine-ECU is defectiveReplace the engine-ECU–

– Blower Motor Assembly, Resistor and Evaporator HEATER AND MANUAL
AIR CONDITIONER55-21
BCASE COVER, EVAPORATOR REMOVAL
The evaporator, which has been installed in a factory, has
no case cover. Follow the steps below to remove that
evaporator.
1. Cut the case along the shown line to remove the cooling
and blower unit.
2. Remove the air thermo sensor from the evaporator, and
then remove the evaporator towards you, being careful
not to damage its core.
INSPECTION
BLOWER MOTOR CHECK
When battery voltage is applied between the terminals, check
that the motor operates. Also, check that there is no abnormal
noise.
RESISTOR CHECK
Use a circuit tester to measure the resistance between the
terminals as indicated below. Check that the measured value
is at the standard value.
Standard value:
Measurement terminalStandard value Ω
Between terminals 3 and 22.81 ± 10%
Between terminals 3 and 41.28 ± 10%
Between terminals 3 and 10.33 ± 10%
Cut line
Evaporator

– Blower Motor Assembly, Resistor and Evaporator HEATER AND MANUAL
AIR CONDITIONER55-22
AIR THERMO-SENSOR CHECK
Measure the resistance between the sensor terminals in two
or more different temperature conditions. The resistance
values must conform to the values shown in the graph.
NOTE
The temperatures at checking must be within the range shown
in the characteristic curve.kΩ
Temperature
Resistance
°C 0
–10 0 10 20 30 40 5 10 15 20

FULL-AUTOMATIC AIR CONDITIONER – Troubleshooting55-34
TROUBLESHOOTING
STANDARD FLOW OF DIAGNOSTIC TROUBLESHOOTING
Refer to GROUP 00 – How to Use Troubleshooting/Inspection Service Points.
DIAGNOSIS FUNCTION
DIAGNOSIS CODES CHECK
Connect the MUT-II or a voltmeter to the diagnosis connector (16-pin), then check diagnosis codes.
(Refer to GROUP 00 – How to Use Troubleshooting/Inspection Service Points.)
ERASING DIAGNOSIS CODES
Refer to GROUP 00 – How to Use Troubleshooting/Inspection Service Points.
INSPECTION CHART FOR DIAGNOSIS CODES
Code No.Diagnosis itemReference
page
11Inside air temperature sensor system (open circuit)55-34
12Inside air temperature sensor system (short circuit)55-34
13Outside air temperature sensor system (open circuit)55-35
14Outside air temperature sensor system (short circuit)55-35
15Heater water temperature sensor system (open circuit)55-36
16Heater water temperature sensor system (short circuit)55-36
21Air thermo sensor system (open circuit)55-37
22Air thermo sensor system (short circuit)55-37
31Potentiometer system of air mix damper assembly55-38
32Potentiometer system of air outlet changeover damper assembly55-39
41Drive system of air mix damper motor assembly55-40
42Drive system of air outlet changeover damper motor assembly55-40
INSPECTION PROCEDURES FOR DIAGNOSIS CODES
Code No.11 Inside air temperature sensor system (open
circuit)Probable cause
This diagnosis code is output if the power supply line or input line of the inside
air temperature sensor inside A/C-ECU is open-circuited and no signal is input
from the inside air temperature sensor to A/C-ECU.
Malfunction of the A/C-ECU
Replace the A/C-ECU.
Code No.12 Inside air temperature sensor system (short
circuit)Probable cause
This diagnosis code is output if the power supply line or input line of the inside
air temperature sensor inside A/C-ECU is short-circuited and inside air
temperature sensor power supply voltage signals are input to A/C-ECU.
Malfunction of the A/C-ECU
Replace the A/C-ECU.

FULL-AUTOMATIC AIR CONDITIONER – Troubleshooting55-35
Code No.13 Outside air temperature sensor system (open
circuit)Probable cause
This diagnosis code is output if the power supply line or input line of the outside
air temperature sensor is open-circuited and no signal is input from the outside
air temperature sensor to A/C-ECU.
Malfunction of the outside air temperature sensor

Malfunction of connector, harness

Malfunction of the A/C-ECU
Outside air temperature sensor check (Refer to P.55-62.)NG
Replace
OK
Measure at the outside air temperature sensor connector A-35.

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

Voltage between terminal (2) and body earth
OK:5 VNGCheck the following connectors:
B-15, B-16
NG
Repair OK
Check the trouble symptom.
NG
Check the harness between the outside air temperature sensor
and the A/C-ECU.
NG
Repair OK
Replace the A/C-ECU.
OK
Measure at the A/C-ECU connector B-04.

Connect the connector.

Voltage between terminal (7) and body earth
OK:2.3 – 2.9 VNGCheck the following connectors:
A-15, B-04
NG
Repair OK
Check the trouble symptom.
NG
Check the harness between the outside air temperature sensor
and the A/C-ECU, and repair if necessary.
OK
Check the following connector: B-04NG
Repair
OK
Check the trouble symptom.NGReplace the A/C-ECU.
Code No.14 Outside air temperature sensor system (short
circuit)Probable cause
This diagnosis code is output if the power supply line or input line of the outside
air temperature sensor is short-circuited and outside air temperature sensor power
supply voltage signals are input to A/C-ECU.
Malfunction of the outside air temperature sensor

Malfunction of connector, harness

Malfunction of the A/C-ECU
Outside air temperature sensor check (Refer to P.55-62.)NG
Replace
OK
Measure at the A/C-ECU connector B-04.

Connect the connector.

Voltage between terminal (7) and body earth
OK:2.3 – 2.9 VNGCheck the harness between the outside air temperature sensor
and the A/C-ECU, and repair if necessary.
OK
Replace the A/C-ECU.

FULL-AUTOMATIC AIR CONDITIONER – Troubleshooting55-36
Code No.15 Heater water temperature sensor system
(open circuit)Probable cause
This diagnosis code is output if the power supply line or input line of the heater
water temperature sensor is open-circuited and no heater water temperature sensor
signals are input to A/C-ECU.
Malfunction of the heater water temperature
sensor

Malfunction of connector, harness

Malfunction of the A/C-ECU
Heater water temperature sensor check (Refer to P.55-64.)NG
Replace
OK
Measure at the heater water temperature sensor connector B-02.

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

Voltage between terminal (1) and body earth
OK:5 VNGCheck the following connector:
B-04
NG
Repair OK
Check the trouble symptom.
NG
Check the harness between the heater water temperature sensor
and the A/C-ECU.
NG
Repair OK
Replace the A/C-ECU.
OK
Measure at the A/C-ECU connector B-04.

Connect the connector.

Voltage between terminal (4) and body earth
OK:2.3 – 2.9 VNGCheck the following connector:
B-02
NG
Repair OK
Check the trouble symptom.
NG
Check the harness between the heater water temperature sensor
and the A/C-ECU, and repair if necessary.
OK
Check the following connector: B-04NG
Repair
OK
Check the trouble symptom.NGReplace the A/C-ECU.
Code No.16 Heater water temperature sensor system
(short circuit)Probable cause
This diagnosis code is output if the power supply line or output line of the heater
water temperature sensor is short-circuited and heater water temperature sensor
power supply voltage signals are input to A/C-ECU.
Malfunction of the heater water temperature
sensor

Malfunction of connector, harness

Malfunction of the A/C-ECU
Heater water temperature sensor check (Refer to P.55-64.)NG
Replace
OK
Measure at the A/C-ECU connector B-04.

Connect the connector.

Voltage between terminal (4) and body earth
OK:2.3 – 2.9 VNGCheck the harness between the heater water temperature sensor
and the A/C-ECU, and repair if necessary.
OK
Replace the A/C-ECU.

FULL-AUTOMATIC AIR CONDITIONER – Troubleshooting55-37
Code No.21 Air thermo sensor system (open circuit)Probable cause
This diagnosis code is output if the power supply line or input line of the air thermo
sensor is open-circuited and no air thermo sensor signals are input to A/C-ECU.
Malfunction of the air thermo sensor

Malfunction of connector, harness

Malfunction of the A/C-ECU
Air thermo sensor check (Refer to P.55-22.)NG
Replace
OK
Measure at the air thermo sensor connector B-03.

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

Voltage between terminal (2) and body earth
OK:5 VNGCheck the following connector:
B-04
NG
Repair OK
Check the trouble symptom.
NG
Check the harness between the air thermo sensor and the
A/C-ECU.
NG
Repair OK
Replace the A/C-ECU.
OK
Measure at the A/C-ECU connector B-04.

Connect the connector.

Voltage between terminal (8) and body earth
OK:2.3 – 2.9 VNGCheck the following connector:
B-03
NG
Repair OK
Check the trouble symptom.
NG
Check the harness between the air thermo sensor and the
A/C-ECU, and repair if necessary.
OK
Check the following connector: B-04NG
Repair
OK
Check the trouble symptom.NGReplace the A/C-ECU.
Code No.22 Air thermo sensor system (short circuit)Probable cause
This diagnosis code is output if the power supply line or output line of the air thermo
sensor is short-circuited and air thermo sensor power supply voltage signals are
input to A/C-ECU.
Malfunction of the air thermo sensor

Malfunction of connector, harness

Malfunction of the A/C-ECU
Air thermo sensor check (Refer to P.55-22.)NG
Replace
OK
Measure at the A/C-ECU connector B-04.

Connect the connector.

Voltage between terminal (8) and body earth
OK:2.3 – 2.9 VNGCheck the harness between the air thermo sensor and the
A/C-ECU, and repair if necessary.
OK
Replace the A/C-ECU.

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.