Mitsubishi Lancer Evolution VI. Manual - part 121

FULL-AUTOMATIC AIR CONDITIONER – 

Troubleshooting

55-36

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.

D

Malfunction of the heater water temperature
sensor

D

Malfunction of connector, harness

D

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.

D

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

D

Voltage between terminal (1) and body earth
OK: 5 V

NG

Check 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.

D

Connect the connector.

D

Voltage between terminal (4) and body earth
OK: 2.3  – 2.9 V

NG

Check 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-04

NG

Repair

OK

Check the trouble symptom.

NG

Replace 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.

D

Malfunction of the heater water temperature
sensor

D

Malfunction of connector, harness

D

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.

D

Connect the connector.

D

Voltage between terminal (4) and body earth
OK: 2.3  – 2.9 V

NG

Check 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 – 

Troubleshooting

55-37

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.

D

Malfunction of the air thermo sensor

D

Malfunction of connector, harness

D

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.

D

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

D

Voltage between terminal (2) and body earth
OK: 5 V

NG

Check 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.

D

Connect the connector.

D

Voltage between terminal (8) and body earth
OK: 2.3  – 2.9 V

NG

Check 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-04

NG

Repair

OK

Check the trouble symptom.

NG

Replace 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.

D

Malfunction of the air thermo sensor

D

Malfunction of connector, harness

D

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.

D

Connect the connector.

D

Voltage between terminal (8) and body earth
OK: 2.3  – 2.9 V

NG

Check 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 – 

Troubleshooting

55-38

Code No.31 Potentiometer system of air mix damper motor
assembly

Probable cause

This diagnosis code is output if no signals are input from air mix damper potentiometer
to A/C-ECU because of short-circuit or open-circuit in the harness.

D

Malfunction of the air mix damper potentiometer

D

Malfunction of connector, harness

D

Malfunction of the A/C-ECU

Air mix damper potentiometer check (Refer to P.55-59.)

NG

Replace

OK

Measure at the air mix damper potentiometer connector B-39.

D

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

D

Voltage between terminal (6) and body earth
OK: 5 V

NG

Check the following connector:
B-04

NG

Repair

OK

Check the trouble symptom.

NG

Check the harness between the air mix damper potentiometer
and the A/C-ECU.

NG

Repair

OK

Replace the A/C-ECU.

OK

Measure at the A/C-ECU connector B-04.

D

Connect the connector.

D

Air mix damper position: MAX.HOT

D

Voltage between terminal (5) and body earth
OK: 4.7  – 5.0 V

NG

Check the following connector:
B-39

NG

Repair

OK

Check the trouble symptom.

NG

Check the harness between the air mix damper potentiometer
and the A/C-ECU, and repair if necessary.

OK

Check the following connector: B-04

NG

Repair

OK

Check the trouble symptom.

NG

Replace the A/C-ECU.

FULL-AUTOMATIC AIR CONDITIONER – 

Troubleshooting

55-39

Code No.32 Potentiometer system of air outlet changeover
damper motor assembly

Probable cause

This diagnosis code is output if no signals are input from air outlet changeover
damper potentiometer to A/C-ECU because of short-circuit or open-circuit in the
harness.

D

Malfunction of the air outlet changeover damper
potentiometer

D

Malfunction of connector, harness

D

Malfunction of the A/C-ECU

Air outlet changeover damper potentiometer check (Refer to
P.55-60.)

NG

Replace

OK

Measure at the air outlet changeover damper potentiometer con-
nector B-06.

D

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

D

Voltage between terminal (2) and body earth
OK: 5 V

NG

Check the following connector:
B-04

NG

Repair

OK

Check the trouble symptom.

NG

Check the harness between the air outlet changeover damper
potentiometer and the A/C-ECU.

NG

Repair

OK

Replace the A/C-ECU.

OK

Measure at the A/C-ECU connector B-04.

D

Connect the connector.

D

Air outlet changeover damper position: DEF

D

Voltage between terminal (6) and body earth
OK: 4.8  – 5.2 V

NG

Check the following connector:
B-06

NG

Repair

OK

Check the trouble symptom.

NG

Check the harness between the air outlet changeover damper
motor potentiometer and the A/C-ECU, and repair if necessary.

OK

Check the following connector: B-04

NG

Repair

OK

Check the trouble symptom.

NG

Replace the A/C-ECU.