Monday, December 2, 2019

2019 Cadillac Truck Escalade AWD V8-6.2L Diagnostic Instructions Page 718


* 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) 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) Wiring Repairs



Scan Tool Reference



Control Module References (See: Testing and Inspection/Programming and Relearning) Control Module References for scan tool information



Circuit/System Verification



Ignition ON, observe the scan tool A/C Evaporator Temperature Sensor parameter. The reading should be between -39锟斤拷F (-35锟斤拷C) and 208锟斤拷F (98锟斤拷C)



and change with evaporator air temperature changes.



Circuit/System Testing



Important: If the evaporator air temperature sensor has an out of range condition caused by a short to voltage, short to ground, or an



open/high resistance, the scan tool will display the same value: 11锟斤拷C (51锟斤拷F).



1. Ignition OFF, disconnect the harness connector at the evaporator air temperature sensor.



2. Ignition OFF, test for less than 10 ohms between the low reference circuit terminal 2 and ground.



锟斤拷 If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the HVAC



control module.



3. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal 1 and low reference circuit terminal 2.



锟斤拷 If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the



HVAC control module.



锟斤拷 If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HVAC control



module.



4. If all circuits test normal, test or replace the evaporator air temperature sensor.



Component Testing



1. Test the evaporator air temperature sensor by varying the sensor temperature while monitoring the sensor resistance.



2. Compare the readings with the Sensor Resistance Table (See: Heating and Air Conditioning/Specifications/Electrical Specifications) Sensor



Resistance Table and verify that the resistance is within 5 percent of the specification.



锟斤拷 If not within the specified range, replace the sensor.



Repair Instructions



Perform the Diagnostic Repair Verification (See: Verification Tests) Diagnostic Repair Verification after completing the diagnostic procedure.



* Air Conditioning Refrigerant Temperature Sensor Replacement (See: Heating and Air Conditioning/Refrigerant Temperature Sensor/Service



and Repair/HVAC - Automatic) Evaporator Air Temperature Sensor Replacement



* Control Module References (See: Testing and Inspection/Programming and Relearning) Control Module References for HVAC control



module replacement, setup, and programming



HVAC - Manual



DTC B3933



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



Instructions) provides an overview of each diagnostic category.



DTC Descriptors



DTC B3933 02



- Evaporator Air Temperature Sensor Short to Ground

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