DTC B2B11

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 B2B11 Serial Data Gateway Module System Voltage Low For symptom byte information refer to Symptom Byte List. Diagnostic Fault Information

Circuit Number	Circuit Function	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performan
3340	B+	B2B11	B2B11	—	—
1851	Ground	—	B2B11	—	—

Circuit/System Description The K56 Serial Data Gateway Module monitors the system voltage on the B+ circuit 3340 to ensure that it stays within the proper range. An open or high resistance on the B+ circuit 3340 or ground circuit 1851 may affect the modules ability to monitor and report the correct system voltage. Conditions for Running the DTC Ignition On Conditions for Setting the DTC B+ circuit is less than 9 V for more than 5 s B+ circuit is greater than 15 V for more than 5 s Ground circuit has an open or high resistance Actions Taken When the DTC Sets A message and/or warning indicator may be displayed to the driver The K56 Serial Data Gateway Module may be disabled Conditions for Clearing the DTC The conditions for setting the DTC are no longer present A history DTC will clear after 100 consecutive ignition cycles without a fault Diagnostic Aids If the fault is not current, the high system voltage could be a result of overcharging with a battery charger or after jump starting the vehicle. Reference Information Schematic Reference Data Communication Schematics Control Module References Connector End View Reference Master Electrical Component List 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 Reference Control Module References Circuit/System Verification

1. Ignition ON.

Note

A low or high voltage DTC may set in multiple control modules due to a concern with the battery or charging system.

2. Verify there are no system voltage DTCs set as current or history in any control module. ⇒ If any system voltage DTCs are set Diagnose these DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle. ⇓ If not system voltage DTCs are set
3. Ignition Off and all vehicle systems OFF.

Note

The battery voltage should stabilize after a few minutes of turning the ignition/vehicle Off.

4. Verify the battery voltage is between 12.4 V to 12.8 V at the C1 Battery. ⇒ If not between the specified range Refer to Battery Inspection/Test ⇓ If between the specified range
5. Start the engine with all accessories off, allow the system voltage to stabilize.
6. Test for 13 V to 15 V at the C1 Battery. ⇒ If not the specified value Refer to Charging System Test ⇓ If between the specified range
7. Verify DTC B2B11 is set as current. ⇒ If DTC B2B11 is set as current Refer to Circuit/System Testing. ⇓ If DTC B2B11 is not set as current
8. A fault is not currently present and may be an intermittent condition. Circuit/System Testing
9. Ignition Off, disconnect the X1 connector at the K56 Serial Data Gateway Module.
10. Verify a test lamp illuminates between ground circuit terminal 4 X1 and B+ ⇒ If the test lamp does not illuminate Repair the open/high resistance on circuit 1851 or the ground connection. ⇓ If the test lamp illuminates
11. Ignition ON.
12. Verify a test lamp Illuminates between B+ circuit terminal 1 X1 and ground. ⇒ If the test lamp does not illuminate and the circuit fuse is good 4.1. Test the B+ circuit 3340 for an open/high resistance. ⇒ if an open/high resistance is found, repair the fault on the circuit. ⇓ If an open or high resistance is not found 4.2. Verify the fuse is not open and there is voltage at the fuse. ⇒ If the test lamp does not illuminate and the circuit fuse is open 4.1. Test the B+ circuit 3340 for a short to ground ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 4.2. Replace the K56 Serial Data Gateway Module. ⇓ If the test lamp illuminates
13. Verify voltage at B+ terminal 1 X1 is within 1 V of the C1 Battery voltage. ⇒ If not the specified value Repair the high resistance on circuit 3340. ⇓ If the specified value
14. Replace the K56 Serial Data Gateway Module. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Control Module References for control module replacement, programming, and setup