2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 2042
3. With the prior control modules disconnected, repeat steps 1 and 2 for each control module on the circuit except the BCM.
4. Ignition OFF, disconnect the X 4 harness connector at the K9 BCM.
5. Test for infinite resistance between the serial data communication enable circuit terminal 22 and ground.
瀚慖f less than infinite resistance, repair the enable circuit for a short to ground.
6. If all circuits tests normal, replace the K9 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
U2099
DTC U2099
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 U2099 00
- High Speed Communication Enable Circuit
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) activates the serial data communication enable circuit, when the ignition key is in ACC, ON or START. The serial
data communication enable circuit wakes up the modules for serial data buss communication.
Conditions for Running the DTC
* The system voltage is between 9-16 volts.
* The vehicle power mode master requires serial data communication to occur.
Conditions for Setting the DTC
The BCM senses a short to ground on the serial data communication enable circuit.
Action Taken When the DTC Sets
* The output command is turned off while the malfunction is present.
* The modules use a default value for the missing parameters until the next ignition cycle.
* The module(s) is never signaled, therefore the specific subsystem(s) will not function.
* The vehicle will not start while the circuit is shorted to ground.
Conditions for Clearing the DTC
* A current DTC clears when the malfunction is no longer present.
* A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
