2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 246
Danger: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal
Protection Equipment (PPE) and proper procedures must be followed.
The High Voltage Disabling procedure will perform the following tasks:
* Identify how to disable high voltage.
* Identify how to test for the presence of high voltage.
* Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must
be followed.
Failure to follow the procedures exactly as written may result in serious injury or death.
1. Perform the High Voltage Disabling (See: Hybrid Drive Systems/Battery System, Hybrid Drive/Testing and Inspection/Initial Inspection
and Diagnostic Overview/High Voltage Disabling) procedure.
2. Reconnect the 12-volt battery.
3. Ignition OFF, disconnect harness connector X1 of the drive motor generator battery control module and the PIM.
4. Ignition ON, verify that a test lamp illuminates between the wake up signal circuit of the PIM and ground, and the drive motor generator
battery control module and ground as follows:
* PIM X1 19
* BECM X1 12
瀚慖f the test lamp does not illuminate, test the circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the
SDG module.
5. Ignition OFF, verify that a test lamp does not illuminate between the PIM wake up signal circuit terminal 19 and ground.
瀚慖f the test lamp illuminates, test the circuit for a short to voltage. If the circuit tests normal, replace the SDG module.
6. If all circuits test normal, replace the SDG module.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning) for module replacement, setup, and programming
B137B
DTC B137B
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 B137B 06
- Accessory Power Module Wake Up Circuit - short to ground or open
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
