2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 3311

2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 3311

U0100

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.

U1888

DTC U1888

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 U1888 00

- Lost Communication with Battery Pack

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 gateway (SDG) module translates serial data messages between the high speed GMLAN serial data bus, the low speed GMLAN

serial data bus, and the high speed hybrid GMLAN serial data bus. Messages between the drive motor generator battery control module and the

other hybrid system control modules must pass thru the SDG module. 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.

DTC U1888 is set by the drive motor generator battery control module, but is stored in and reported by the hybrid powertrain control modul

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.

Conditions for Setting the DTC

A supervised periodic message that includes the transmitter module availability has not been received.

Action Taken When the DTC Sets

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