2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 3184
* U1814
* U2099
SDGM
* U1812
* B1453
If any listed DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic
Trouble Code (DTC) List - Vehicle) to diagnose that DTC prior to this diagnostic.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector X2 at the SDGM.
2. Verify less than 0.5 volts between the wake up signal circuit terminal 19 and ground.
瀚慖f greater than the specified range, test the circuit for a short to voltage. If the circuit tests normal, replace the BCM.
3. Ignition ON, verify B+ between the communication enable signal circuit terminal 16 and ground.
瀚慖f less than the specified value, test the circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
4. If all circuits test normal, replace the SDGM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Wiring Repairs/GMLAN Wiring Repairs)
U209D
DTC U209D
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 U209D 00
- Battery Energy Control Module High Speed Communication Enable Circuit High
Diagnostic Fault Information
Circuit/System Description
Modules connected to the LAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information
and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on
the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as
an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.
2 wake up signal circuits (5986, 5985) are energized by the body control module (BCM) to activate multiple modules including the drive motor
generator battery control module (BECM) when serial data is required. Wake up signal circuit (968) is energized by the serial data gateway module
(SDGM) to activate the BECM immediately after the BCM energizes circuit 5986 and 5985. The BECM compares the status of both wake up
