Service Information
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic approach.
- Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
- DTC B2B12
Central Gateway Module Control Module Memory Failure
- DTC B2B13
Central Gateway Module Control Module Internal Performance Failure
For symptom byte information, refer to Symptom Byte List.
Circuit/System Description
This diagnostic applies to internal microprocessor integrity conditions within the device. The device 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 device.
Reference Information
Schematic ReferenceConnector End View ReferenceMaster Electrical Component List
Description and OperationData Link Communications Description and Operation
Electrical Information Reference- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool ReferencesControl Module References for scan tool information
Circuit/System Verification
- Ignition ON/Vehicle in Service Mode.
- Verify that 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
- All OK
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Control Module References for device replacement, programming and setup