2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2775
* 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 () procedure.
2. Ignition OFF, disconnect harness connector X1 of the BECM.
3. Reconnect the 12-volt battery.
4. Ignition OFF and scan tool disconnected, test for less than 1 volt between wake up signal terminal 13 and ground.
瀚慖f greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM.
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
U0210
DTC U0100-U02FF (without HP2)
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
Refer to Control Module U Code List (See: Diagnostic Trouble Code Descriptions/Control Module U Code List).
Diagnostic Fault Information
Circuit/System Description
The serial data circuit is the means by which the control modules in the vehicle communicate with each other. Once the scan tool is connected to the
serial data circuit through the DLC, the scan tool can be used to monitor each control module for diagnostic purposes and to check for diagnostic
trouble codes (DTCs). When the ignition switch is in RUN, each control module communicating on the serial data circuit sends a state of health
(SOH) message to ensure that the control module is operating properly. When a control module stops communicating on the serial data circuit, for
example if the module loses power or ground, the SOH message it normally sends on the serial data circuit disappears. Other control modules on
the serial data circuit, which expect to receive that SOH message, detect its absence; those control modules in turn set a DTC associated with the
loss of SOH of the non-communicating control module. The DTC is unique to the control module which is not communicating and one or more
control modules may set the same exact code. A loss of serial data communications DTC does not represent a failure of the control modules that
contain the stored code.
