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Symptom:
A/C COMPRESSOR CONTROL SHORTED LOW (ACTIVE)
POSSIBLE CAUSES
A/C COMPRESSOR CLUTCH
A/C COMPRESSOR CLUTCH CONTROL CIRCUIT SHORTED TO GROUND
A/C COMPRESSOR CLUTCH CONTROL CIRCUIT SHORTED TO GROUND CIRCUIT
A/C COMPRESSOR CLUTCH CONTROL CIRCUIT SHORTED TO SENSOR GROUND CIRCUIT
AUTOMATIC TEMPERATURE CONTROL (ATC)
TEST ACTION APPLICABILITY
1 Turn the ignition on.
Press the Air Conditioning switch off.
Turn the ignition off.
Disconnect the A/C Compressor Clutch harness connector.
Turn the ignition on.
With the DRBIIIt, record and erase Automatic Temperature Control DTCs.
Turn the ignition off, wait 5 seconds, then turn the ignition on.
With the DRBIIIt, read the Automatic Temperature Control DTCs.
Does the DRBIIItdisplay: A/C COMPRESSOR CONTROL HIGH OR OPEN?All
Ye s!Replace the A/C Compressor Clutch in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 2
2 Turn the ignition off.
Disconnect the A/C Compressor Clutch harness connector.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Measure the resistance between ground and the A/C Compressor Clutch Control
circuit.
Is the resistance below 10k ohms?All
Ye s!Repair the A/C Compressor Clutch Control circuit for a short to
ground.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 3
3 Turn the ignition off.
Disconnect the A/C Compressor Clutch harness connector.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Measure the resistance between the A/C Compressor Clutch Control circuit and the
Ground circuit in the Automatic Temperature Control C1 harness connector.
Is the resistance below 10k ohms?All
Ye s!Repair the A/C Compressor Clutch Control circuit for a short to
the Ground circuit.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 4
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HEATING & A/C
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TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the A/C Compressor Clutch harness connector.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Measure the resistance between the A/C Compressor Clutch Control circuit and the
Sensor Ground circuit in the Automatic Temperature Control C1 harness connector.
Is the resistance below 10k ohms?All
Ye s!Repair the A/C Compressor Clutch Control circuit for a short to
the Sensor Ground circuit.
Perform BODY VERIFICATION TEST - VER 1.
No!Replace the Automatic Temperature Control (ATC) in accordance
with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
133
HEATING & A/C
A/C COMPRESSOR CONTROL SHORTED LOW (ACTIVE) ÐContinued
Page 147 of 2305

Symptom:
AIR OUTLET TEMP SENSOR HIGH OR OPEN (ACTIVE)
POSSIBLE CAUSES
AIR OUTLET TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
AUTOMATIC TEMPERATURE CONTROL (ATC)
AUTOMATIC TEMPERATURE CONTROL (ATC)
AIR OUTLET TEMPERATURE SENSOR SIGNAL CIRCUIT OPEN
SENSOR GROUND CIRCUIT OPEN
AIR OUTLET TEMPERATURE SENSOR
TEST ACTION APPLICABILITY
1 Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Air Outlet Temperature Sensor harness connector.
Turn the ignition on.
While back probing, measure the voltage between the Air Outlet Temperature Sensor
Signal circuit and the Sensor Ground circuit.
Is the voltage above 5.3 volts?All
Ye s!Go To 2
No!Go To 3
2 Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Air Outlet Temperature Sensor harness connector.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Turn the ignition on.
Measure the voltage of the Air Outlet Temperature Sensor Signal circuit.
Is the voltage above 0.2 volts?All
Ye s!Repair the Air Outlet Temperature Sensor Signal circuit for a
short to voltage.
Perform BODY VERIFICATION TEST - VER 1.
No!Replace the Automatic Temperature Control (ATC) in accordance
with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Air Outlet Temperature Sensor harness connector.
Turn the ignition on.
While back probing, measure the voltage between the Air Outlet Temperature Sensor
Signal circuit and Sensor Ground circuit in the Automatic Temperature Control
(ATC) C1 harness connector.
Is the voltage above 4.5 volts?All
Ye s!Go To 4
No!Replace the Automatic Temperature Control (ATC) in accordance
with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
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HEATING & A/C
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TEST ACTION APPLICABILITY
4 Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Disconnect the Air Outlet Temperature Sensor harness connector.
Measure the resistance of the Air Outlet Temperature Sensor Signal circuit between
the Automatic Temperature Control (ATC) C1 harness connector and the Air Outlet
Temperature Sensor harness connector.
Is the resistance below 5.0 ohms?All
Ye s!Go To 5
No!Repair the Air Outlet Temperature Sensor Signal circuit for an
open.
Perform BODY VERIFICATION TEST - VER 1.
5 Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Disconnect the Air Outlet Temperature Sensor harness connector.
Measure the resistance of the Sensor Ground circuit between the Automatic
Temperature Control (ATC) C1 harness connector and the Air Outlet Temperature
Sensor harness connector.
Is the resistance below 5.0 ohms?All
Ye s!Replace the Air Outlet Temperature Sensor in accordance with
the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No!Repair the Sensor Ground circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
135
HEATING & A/C
AIR OUTLET TEMP SENSOR HIGH OR OPEN (ACTIVE) ÐContinued
Page 149 of 2305

Symptom:
AIR OUTLET TEMP SENSOR SHORTED LOW (ACTIVE)
POSSIBLE CAUSES
AIR OUTLET TEMPERATURE SENSOR
AIR OUTLET TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
AIR OUTLET TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND CIRCUIT
AUTOMATIC TEMPERATURE CONTROL (ATC)
AIR OUTLET TEMPERATURE SENSOR SIGNAL CIRCUIT SHORT TO SENSOR GROUND CIR-
CUIT
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the Air Outlet Temperature Sensor harness connector.
Turn the ignition on.
With the DRBIIIt, record and erase Automatic Temperature Control DTCs.
Turn the ignition off, wait 5 seconds, then turn the ignition on.
With the DRBIIIt, read the Automatic Temperature Control DTCs.
Does the DRBIIItdisplay: AIR OUTLET TEMP SENSOR HIGH OR OPEN?All
Ye s!Replace the Air Outlet Temperature Sensor in accordance with
the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 2
2 Turn the ignition off.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Measure the resistance between ground and the Air Outlet Temperature Sensor
Signal circuit.
Is the resistance below 10k ohms?All
Ye s!Repair the Air Outlet Temperature Sensor Signal circuit for a
short to ground.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 3
3 Turn the ignition off.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Measure the resistance between the Air Outlet Temperature Sensor Signal circuit
and the Ground circuit.
Is the resistance below 10k ohms?All
Ye s!Repair the Air Outlet Temperature Sensor Signal circuit for a
short to the Ground circuit.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 4
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HEATING & A/C
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TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the Air Outlet Temperature Sensor harness connector.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Measure the resistance between the Air Outlet Temperature Sensor Signal circuit
and the Sensor Ground circuit.
Is the resistance below 10k ohms?All
Ye s!Repair the Air Outlet Temperature Sensor Signal circuit for a
short to the Sensor Ground circuit.
Perform BODY VERIFICATION TEST - VER 1.
No!Replace the Automatic Temperature Control (ATC) in accordance
with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
137
HEATING & A/C
AIR OUTLET TEMP SENSOR SHORTED LOW (ACTIVE) ÐContinued
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Symptom List:
ATC FUNCTION TEST COOL FAILURE
ATC FUNCTION TEST FAILURE
ATC FUNCTION TEST HEAT FAILURE
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be ATC FUNCTION TEST COOL
FAILURE.
When Monitored and Set Condition:
ATC FUNCTION TEST COOL FAILURE
When Monitored: With the engine running.
Set Condition: This DTC will set if specific operating criteria are not met when
attempting to run the ATC Function Test.
ATC FUNCTION TEST FAILURE
When Monitored: With the engine running.
Set Condition: This DTC will set if specific operating criteria are not met when
attempting to run the ATC Function Test.
ATC FUNCTION TEST HEAT FAILURE
When Monitored: With the engine running.
Set Condition: This DTC will set if specific operating criteria are not met when
attempting to run the ATC Function Test.
POSSIBLE CAUSES
ATC FUNCTION TEST OPERATING CRITERIA NOT MET
AUTOMATIC TEMPERATURE CONTROL (ATC) DTC(S) PRESENT
ENGINE CONTROL MODULE DTC(S) PRESENT
CRITERIA TO RUN ATC FUNCTION TEST NOT MET AND NO DTCS PRESENT
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TEST ACTION APPLICABILITY
1 Verify that all of the following criteria was met when attempting to run the ATC
Function Test.
The vehicle was stationary.
The engine was running.
The air conditioning switch was On.
The ambient temperature was above 59ÉF (15ÉC).
The refrigerant pressure was between 29 and 348 PSI (2 and 24 bar).
The evaporator temperature was above 36.5ÉF (2.5ÉC).
The coolant temperature was above 158ÉF (70ÉC).
Was all criteria met when attempting to run the ATC Function Test?All
Ye s!Go To 2
No!Attempt to activate the ATC Function Test when all of the specific
operating criteria are met. If the criteria cannot be met, proceed
to Test 2 of this procedure.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition on.
With the DRBIIIt, read Automatic Temperature Control DTCs.
Does the DRBIIItdisplay any DTCs?All
Ye s!Return to the Heating & A/C symptom list and choose the
symptom(s).
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 3
3 Turn the ignition on.
With the DRBIIIt, read Engine Control Module DTCs.
Does the DRBIIItdisplay any DTCs?All
Ye s!Refer to Powertrain Diagnostic information for the related symp-
tom(s).
Perform BODY VERIFICATION TEST - VER 1.
No!Refer to Service Information to diagnose the system(s) that failed
to meet the ATC Function Test operating criteria.
Perform BODY VERIFICATION TEST - VER 1.
139
HEATING & A/C
ATC FUNCTION TEST COOL FAILURE ÐContinued