2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 385
control module for a stuck or shorted control button.
Conditions for Running the DTC
Battery voltage is between 9-16 volts and data link communications operate normally.
Conditions for Setting the DTC
The HVAC control module has internal fault inside the HVAC control module for a stuck or shorted control button or shorted 5 volt reference
circuit.
Conditions for Clearing the DTC
* A current DTC clears when the malfunction is no longer present.
* A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.
Reference Information
Schematic Reference
HVAC Schematics (See: Heating and Air Conditioning/Diagrams/Electrical Diagrams/HVAC - Manual)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
* Air Temperature Description and Operation (See: Heating and Air Conditioning/Description and Operation/HVAC - Manual/Air
Temperature Description and Operation)Air Temperature Description and Operation
* Air Delivery Description and Operation (See: Heating and Air Conditioning/Description and Operation/HVAC - Manual/Air Delivery
Description and Operation)Air Delivery Description and Operation
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning)for scan tool information
Circuit/System Verification
1. Ignition ON, disconnect the harness connector at the auxiliary HVAC control module, test for 4.8-5.2 volts between the 5-volt reference
circuit terminal 3 and ground.
瀚慖f less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal,
replace the HVAC Control Module.
瀚慖f greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the HVAC
Control Module.
2. Reprogram the HVAC control module that set DTC B1023. The module should successfully reprogram.
瀚慖f the module will not reprogram, replace the HVAC control module that set the DTC.
3. With a scan tool, clear the DTC.
4. Ignition OFF.
5. Wait 60 seconds, then recheck for DTCs. DTC B1023 should not set.
瀚慖f DTC B1023 sets, replace the module.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning)Control Module References for control module
