1999 MITSUBISHI LANCER EVOLUTION VI heater

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 – Troubleshooting55-54
DATA LIST REFERENCE TABLE
Check itemCheck conditionNormal condition
Inside air temperature sensor

MUT-II (11)Ignition switch: ONInside air temperature and temper-
ature displayed on the MUT-II are
identical.
Outside air temperature sen-
sor

MUT-II (13)Ignition switch: ONOutside air temperature and tem-
perature displayed on the MUT-II
are identical.
Heater water temperature
sensor

MUT-II (15)Ignition switch: ONHeater core surface temperature
and temperature displayed on the
MUT-II are identical.
Air thermo sensor

MUT-II (21)Ignition switch: ONEvaporator surface temperature
and temperature displayed on the
MUT-II are identical.
Photo sensor

MUT-II (25)Ignition switch: ONAmount of incident light is propor-
tional to voltage displayed on the
MUT-II.
Air mix damper potentiometer

MUTII(31)
Ignition switch: ONDamper positionOpening degree (%)

MUT-II (31)MAX. HOTApprox. 100
MAX. COOLApprox. 0
Air outlet changeover damper
potentiometer
Ignition switch: ONDamper positionOpening degree (%)
potentiometer

MUT-II (32)FACEApprox. 0
FOOTApprox. 50
FOOT/DEF.Approx. 75
DEF.Approx. 100
CHECK AT THE A/C-ECU TERMINALS
A/C-ECU
The parenthesized values in “Normal condition” column are for your reference.
Terminal
No.
Check itemCheck conditionNormal condition
1Front power transistor collector outputWhen blower switch is at OFFSystem voltage
When blower switch is at LOApprox. 7 V
When blower switch is at HIAlmost no voltage (0 V)
2Front power transistor base outputWhen blower switch is at OFF0 V
When blower switch is at LOApprox. 1.3 V
When blower switch is at HIApprox. 2.5 V
3BackupAt all timesSystem voltage

FULL-AUTOMATIC AIR CONDITIONER – Troubleshooting55-55
Terminal
No.Normal condition Check condition Check item
4Heater water temperature sensor
inputWhen sensor section temperature is
25C (4 kΩ)2.3 – 2.9 V
5Air mix damper potentiometer inputWhen damper is moved to MAX. HOT
position4.7 – 5.0 V
6Air outlet changeover damper poten-
tiometer inputWhen damper is moved to DEF.
position4.8 – 5.2 V
7Outside air temperature sensor inputWhen sensor section temperature is
25C (4 kΩ)2.3 – 2.9 V
8Air thermo sensor inputWhen sensor section temperature is
25C (4 kΩ)2.3 – 2.9 V
9Photo sensor (–)At luminous intensity of 0 lux0 V
At luminous intensity of 100,000 lux or
more–0.1 – 0.2 V
10Sensor power supplyAt all times4.8 – 5.2 V
12Blower motor HI relay (Exciting circuit)When blower switch is in HI1.5 V or less
When blower switch is in a position
other than HISystem voltage
16Rear defoggerWhen rear defogger switch is ON1.5 V or less
When rear defogger switch is OFFSystem voltage
17Diagnosis date outputWhen ignition switch is ON0 V ↔ 12 V
18Diagnosis control outputWhen ignition switch is ONSystem voltage – 2 V
19Photo sensor (+)At all times0 V
20Sensor earthAt all times0 V
21Air outlet changeover damper motor
(FACE)When damper is moved to FACE
position10 V
When damper is moved to DEF.
positionAlmost no voltage
(0.5 V)
22Air mix damper motor (MAX. COOL)When damper is moved to MAX.
COOL position10 V
When damper is moved to MAX. HOT
positionAlmost no voltage
(0.5 V)
23Inside/outside air changeover damper
motor (Inside)When switch is set to inside air
positionAlmost no voltage
(0.5 V)
When switch is set to outside air
position10 V
24Air outlet changeover damper motor
(DEF.)When damper is moved to FACE
positionAlmost no voltage
(0.5 V)
When damper is moved to DEF.
position10 V

FULL-AUTOMATIC AIR CONDITIONER –
Troubleshooting /
On-vehicle Service55-56
Terminal
No.Normal condition Check condition Check item
25Air mix damper motor (MAX. HOT)When damper is moved to MAX.
COOL positionAlmost no voltage
(0.5 V)
When damper is moved to MAX. HOT
position10 V
26Inside/outside air changeover damper
motor (Outside)When switch is set to inside air
position10 V
When switch is set to outside air
positionAlmost no voltage
(0.5 V)
28IG2 power supplyWhen ignition switch is ONSystem voltage
29EarthAt all timesContinuity
30ILL power supplyWhen lighting switch is at ONSystem voltage
34A/C outputWhen A/C is OFF0 V
When A/C is ONSystem voltage
35EarthAt all timesContinuity
ON-VEHICLE SERVICE
REFRIGERANT CHARGING, LEVEL CHECK,
ADDITION AND REMOVAL, PERFORMANCE
TEST, DUAL PRESSURE SWITCH SIMPLE
CHECK
Follow the same procedures as for the heater and manual
air conditioner. (Refer to P.55-6.)

FULL-AUTOMATIC AIR CONDITIONER – On-vehicle Service55-57
POWER RELAY CHECK
Follow the same procedures as for the heater and manual
air conditioner except for the following. (Refer to P.55-13.)
BLOWER HIGH SPEED RELAY
Battery voltageTerminal No.
1234
Power is not supplied
Power is supplied
IDLE-UP OPERATION CHECK
The idle-up inspection procedures are the same as for the
heater and manual air conditioner. (Refer to P.55-14.)

Standard value: 750 ± 50 r/min

Standard value: 850 ± 50 r/min
NOTE
If the idling speed is not within the standard value range,
adjust it.
Blower high speed relay

FULL-AUTOMATIC AIR CONDITIONER –
Heater Water
Temperature Sensor55-63
HEATER WATER TEMPERATURE SENSOR
REMOVAL AND INSTALLATION
Pre-removal and Post-installation Operation

Floor Console Removal and Installation

Glove Box Removal and Installation

Foot Duct Removal and Installation
(Refer to P55-31.)
1 2
Removal steps
AA1. Heater water temperature sensor clip
AA2. Heater water temperature sensor
REMOVAL SERVICE POINT
AHEATER WATER TEMPERATURE SENSOR CLIP
AND HEATER WATER TEMPERATURE SENSOR
REMOVAL
Pull out the heater water temperature sensor clip which is
at the bottom of the heater unit, and then remove the heater
water temperature sensor from the heater unit.
INSTALLATION SERVICE POINT
AHEATER WATER TEMPERATURE SENSOR AND
HEATER WATER TEMPERATURE SENSOR CLIP
INSTALLATION
Insert the heater water temperature sensor into its mounting
hole at the bottom of the heater unit, and then fix it by inserting
the heater water temperature sensor clip.
Heater unit
Heater water
temperature
sensor clip

FULL-AUTOMATIC AIR CONDITIONER –
Heater Water Temperature Sensor /
Other Maintenance Service Points55-64
INSPECTION
Follow the same procedure as for the inspection of the outside
temperature sensor. (Refer to P55-62.)
OTHER MAINTENANCE SERVICE POINTS
The following maintenance service points are the same as for the manual A/C.
ItemsReference page
Dual Pressure Switch55-13
Blower Relay, A/C Compressor Relay, Condenser Fan Relay, Radiator Fan Relay55-13, 14
Idle-up System55-14
Heater Unit, Cooling and Blower Unit55-15
Blower Motor Assembly, Evaporator55-19
Compressor, Tension Pulley55-23
Condenser, Condenser Fan55-28
Ducts55-31

C-2
STOP LAMP 51. . . . . . . . . . . . . . . . . . . . . . . . . .
BACK-UP LAMP 52. . . . . . . . . . . . . . . . . . . . . . .
METER AND GAUGE 54. . . . . . . . . . . . . . . . . .
FUEL WARNING LAMP 56. . . . . . . . . . . . . . . .
BRAKE WARNING LAMP 56. . . . . . . . . . . . . .
OIL PRESSURE WARNING LAMP 57. . . . . .
SEAT BELT WARNING LAMP 57. . . . . . . . . .
CENTRAL DOOR LOCKING SYSTEM 58. .
Without Keyless Entry System 58. . . . . . . . . . . .
With Keyless Entry System 60. . . . . . . . . . . . . . .
HEATER AND AIR CONDITIONER 64. . . . . .
FULL-AUTO AIR CONDITIONER 70. . . . . . . .
WINDSHIELD WIPER AND WASHER 78. .
With Intermittent Wiper 78. . . . . . . . . . . . . . . . . . .
REAR WIPER AND WASHER 79. . . . . . . . . .
DEFOGGER AND DOOR MIRROR
HEATER 80. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Without Full-Auto Air Conditioner 80. . . . . . . . . .
With Full-Auto Air Conditioner 82. . . . . . . . . . . . .
RADIO 84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Radio Spare Circuit 84. . . . . . . . . . . . . . . . . . . . . .
4 Speaker, 6 Speaker 86. . . . . . . . . . . . . . . . . . . .
KEY REMINDER BUZZER 89. . . . . . . . . . . . . .
ANTI-SKID BRAKING SYSTEM (ABS) 90. .
SUPPLEMENTAL RESTRAINT SYSTEM
(SRS) 96. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ACTIVE YAW CONTROL SYSTEM (AYC) 98
INTERCOOLER AND RADIATOR WATER
SPRAY SYSTEM 104. . . . . . . . . . . . . . . . . . . . .