2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 3305
With a scan tool, ensure the following DTCs are not present in the modules as follows:
BCM
U2099
PSCM
U0146
SDGM
* SDGM - U0111
* SDGM - 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.
U1876
DTC U1876
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 Descriptor
DTC U1876 00
- Drive Motor Control Module A Lost Communication With Engine Control Module (ECM)
Diagnostic Fault Information
Circuit/System Description
Modules connected to the high and low speed GMLAN 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.
The serial data communication enable and the accessory wake up serial data circuits are energized by a specific module to activate another specific
module when the ignition key is in ACC, ON or START. Only the modules using high speed GMLAN serial data are connected to the enable or
wake up circuits. Refer to the schematics to determine which modules activate and are activated using the enable or wake up circuits.
Conditions for Running the DTC
* The system voltage is between 9-16 volts.
* The vehicle power mode master requires serial data communication to occur fro this specific module.
