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Tahoe / Yukon Service Manual

DTC B2B12 or B2B13

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 Serial Data Gateway Module Control Module Memory Performance DTC B2B12 Serial Data Gateway Module Control Module Internal Performance DTC B2B13 For symptom byte information, refer to Symptom Byte List. Circuit/System Description This diagnostic applies to internal microprocessor integrity conditions within the control module. The control module monitors its ability to read and write to the memory. No external circuits are involved. Conditions for Running the DTC The ignition is ON. The system voltage is greater than 9.5 V. Conditions for Setting the DTC The K56 Serial Data Gateway Module detects an internal malfunction. Action Taken When the DTC Sets DTC B2B12 and B2B13 are Type B DTCs. Conditions for Clearing the DTC DTC B2B12 and B2B13 are Type B DTCs. Diagnostic Aids If stored only as a history DTC and not retrieved as a current DTC, do not replace the control module. Reference Information Schematic Reference Data Communication Schematics Control Module References Connector End View Reference Master Electrical Component List Description and Operation Data Link Communications Description and Operation Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs DTC Type Reference Powertrain Diagnostic Trouble Code (DTC) Type Definitions Scan Tool References Control Module References for scan tool information Circuit/System Verification

  1. Ignition ON/Vehicle in Service Mode.
  2. Verify DTC B2B12 or B2B13 is not set. ⇒ If any of the DTCs are set Replace the K56 Serial Data Gateway Module. ⇓ If none of the DTCs are set
  3. All OK Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification For control module replacement, programming, and setup refer to: Control Module References