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Tahoe / Yukon Service Manual

DTC B19DA

Cellular, Entertainment, and Navigation | Diagnostic Information and Procedures | Document ID: 5159506 Diagnostic Instructions Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions DTC Descriptor DTC B19DA Backup Power Source Symptom Byte Information: Symptom Byte List Circuit/System Description The backup power source provides voltage to the K73 Telematic Control Module to be able to successfully place a call in the event of a main battery disconnect during a collision event. The Communication Interface Module Battery is under an access cover on the K73 Telematic Control Module. Conditions for Running the DTC B19DA Ignition/Vehicle = On System Voltage = 9.5 to 15.5 V The above condition(s) must occur for greater than 10 s. Conditions for Setting the DTC B19DA 13 Backup Power Source — Open Circuit B19DA 16 Backup Power Source — Voltage = Less than a predefined threshold — At least 1 time(s) during the ignition cycle B19DA 17 Backup Power Source — Voltage = Greater than a predefined threshold B19DA 4B Backup Power Source — Temperature = Greater than a predefined threshold Actions Taken When the DTC Sets B19DA Red LED = ON The K73 Telematic Control Module will be unable to place a call in the event of a main battery disconnect during a collision event. Conditions for Clearing the DTC Conditions for Clearing the DTC B19DA DTC Pass Counter = passed — For 10 consecutive events. Diagnostic Aids Shorting the backup battery plus circuit to the ground circuit or chassis ground will trigger the internal fuse, rendering the battery inoperative. When the power supply to the K73 Telematic Control Module is disconnected, the control module draws power from its backup battery. Never disconnect the K73 Telematic Control Module connector with the key in the ON position. Reference Information Schematic Reference OnStar/Telematics Schematics Connector End View Reference Master Electrical Component List Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References Circuit/System Verification

  1. Verify DTC B19DA is not set. ⇒ If DTC B19DA is set Test or replace the Communication Interface Module Battery.
  2. Verify DTC B19DA is not set. ⇒ If DTC B19DA is set Test or replace the K73 Telematic Control Module ⇓ If DTC B19DA is not set
  3. A fault is currently not present and may be an intermittent condition. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Communication Interface Module Battery Replacement For control module replacement, programming, and setup refer to: Control Module References