2010 Cadillac CTS Sedan AWD V6-3.6L Page 233
* Air temperature actuator-left terminal 3 and terminal 1
* Air temperature actuator-right terminal 3 and terminal 2
* Mode actuator terminal 3 and terminal 2
* Recirculation actuator terminal 5 and terminal 1
瀚慖f greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal,
replace the HVAC control module.
8. Ignition OFF, test for less than 10 ohms between the following control circuit terminal and ground.
* Air temperature actuator-left terminal 5
* Air temperature actuator-right terminal 5
* Mode actuator terminal 5
* Recirculation actuator terminal 6
瀚慖f greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace
the HVAC control module.
9. Ignition OFF, test for less than 10 ohms between the following control circuit terminal and ground.
* Air temperature actuator-left terminal 4
* Air temperature actuator-right terminal 4
* Mode actuator terminal 4
* Recirculation actuator terminal 7
瀚慖f greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace
the HVAC control module.
10. Connect a test lamp between following control circuit terminals.
* Air temperature actuator-left terminal 5 and terminal 4
* Air temperature actuator-right terminal 5 and terminal 4
* Mode actuator terminal 5 and terminal 4
* Recirculation actuator terminal 6 and terminal 7
11. Ignition ON, command the appropriate actuator door in both directions with a scan tool. The test lamp should turn ON and OFF when
commanded in both directions.
瀚慖f the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal,
replace the HVAC control module.
12. If both circuits test normal, test or replace the actuator.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Air Inlet Valve Actuator Replacement (Left Hand Drive) (See: Heating and Air Conditioning/Air Door/Air Door Actuator / Motor/Service
and Repair/Air Inlet Valve Actuator Replacement)Air Inlet Valve Actuator Replacement (Right Hand Drive) (See: Application and ID)
* Mode Valve Actuator Replacement (See: Heating and Air Conditioning/Air Door/Air Door Actuator / Motor/Service and Repair/Mode
Valve Actuator Replacement)
* Temperature Valve Actuator Replacement - Left Side (See: Heating and Air Conditioning/Air Door/Air Door Actuator / Motor/Service and
Repair/Temperature Valve Actuator Replacement - Left Side)
* Temperature Valve Actuator Replacement - Right Side (See: Heating and Air Conditioning/Air Door/Air Door Actuator / Motor/Service
and Repair/Temperature Valve Actuator Replacement - Right Side)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for the HVAC control module replacement, setup,
and programming
B0423
DTC B0248, B0268, B0408, B0413, B0418, B0423, B3761, or B3773
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
