Component Location

General Description

DTC Description

DTC Detecting Condition

Item	Detecting Condition	Possible Cause
DTC Strategy	• Resistance check	• Short circuit in harness • Faulty Evaporator sensor • Faulty A/C Control Unit
Threshold value	• <2.4kΩ
Detecting time	• 0.3sec
FAIL SAFE	• Control with the value of -2°C

Signal Waveform And Data

Temperature(°C)	Resistance(kΩ)	Temperature(°C)	Resistance(kΩ)
-10	43.3	20	12.1
0	27.6	30	8.3
10	18	40	5.8

Schematic Diagram

Monitor DTC Status

1.	Connect scantool to Data Link Connector(DLC).

2.	Warm up the engine to normal operating temperature.

3.	Monitor DTC(Diagnostics Trouble Code) on the scantool.

4.

Is the same DTC displayed again? ▶ Go to " Inspection/Repair " procedure . ▶ Fault is intermittent caused by poor contact in the sensor's and/or A/C-ECM connector or was repaired and A/C-ECM memory was not cleared. Thoroughly check connectors for looseness, poorconnection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of vehicle Repair" procedure.

W/harness Inspection

1.	Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

2.	Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration,or damage.

3.	Has a problem been found? ▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure ▶ Go to "Signal circuit Short Inspection" procedure.

Signal Circuit Short Inspection

1.	Ignition "OFF".

2.	A/C-ECU : Connect, Evaporator sensor : Disconnect.

3.	Measure resistance between Signal(+) terminal of Evaporator sensor harness connector and and chassis ground . Specification : Infinity

4.	Is "resistance" display near the specified value? ▶ Go to " Component inspection " procedure . ▶ Check for short to ground in harness. ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.

Component Inspection

Check Evaporator sensor

1.	Ignition "OFF"

2.	A/C-ECU, Evaporator sensor : Connect.

3.

Measure resistance between Signal(+) terminal of Evaporator sensor harness connector and Sensor ground terminal of ambient sensor harness connector .(Component side) Specification : Refer the specifications in fig.1 Temperature(°C) Resistance(kΩ) Temperature(°C) Resistance(kΩ) -10 43.3 20 12.1 0 27.6 30 8.3 10 18 40 5.8 ※ Resistance value of evaporator sensor as a function of temperature.

4.	Is "resistance" display near the specified value? ▶ Go to "Check A/C-ECU" procedure. ▶ Substitute with a known-good Evaporator sensor and check for proper operation. If the problem is corrected, replace Evaporator sensor and then go to "Verification of Vehicle Repair" procedure.

1.	Ignition "OFF"

2.	A/C-ECU : Connect, Evaporator sensor : Disconnect.

3.	Ignition "ON"(ENGINE "OFF").

4.	Measure voltage between Signal(+) terminal of Evaporator sensor harness connector and and chassis ground .(Component side) Specification : approx. 5V

5.

Is "voltage" display near the specified value? ▶ Check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure. ▶ Substitute with a known-good A/C-ECU and check for proper operation. If the problem is corrected, replace A/C-ECU and then go to "Verification of Vehicle Repair" procedure.

Verification Of Vehicle Repair

1.	Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.

2.	Using scantool, Clear DTC.

3.	Operate the vehicle within DTC Enable conditions in General information.

4.	Are any DTCs present? ▶ Go to the applicable troubleshooting procedure. ▶ System is performing to specification at this time.