2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 2018
Circuit Description
Modules connected to the GMLAN serial data circuits monitor for serial data communications on the GMLAN network during normal vehicle
operation. Operating information and commands are exchanged among the modules. Each module on GMLAN network maintains a transmit error
counter (TEC) and a receive error counter (REC). The counter values increase with detected errors and will decrease with error-free messages. If
the TEC value exceeds 255 the controller removes itself from the network and a DTC U0001 will be set.
Conditions for Running the DTC
* Voltage supplied to the module is in the normal operating voltage range.
* The vehicle power mode requires serial data communication to occur.
Conditions for Setting the DTC
A certain number of no valid transmitted messages on the GMLAN serial data circuits are detected by the module.
Action Taken When the DTC Sets
* The module suspends all message transmission.
* The module uses default values for all parameters received on the GMLAN serial data circuits.
* The module inhibits the setting of all other GMLAN communication DTCs.
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, without a repeat of the malfunction.
Diagnostic Aids
* This DTC cannot be retrieved with a current status. Diagnosis of current DTC is accomplished via the symptom, Scan Tool Does Not
Communicate with GMLAN Device. Refer to Scan Tool Does Not Communicate with High Speed GMLAN Device (See: Powertrain
Management/Computers and Control Systems/Information Bus/Testing and Inspection/Symptom Related Diagnostic Procedures/Scan Tool
Does Not Communicate with High Speed GMLAN Device).
* An intermittent condition is likely to be caused by a short on the GMLAN serial data circuits. Use the Scan Tool Does Not Communicate
with GMLAN Device procedure in order to isolate an intermittent condition. Refer to Scan Tool Does Not Communicate with High Speed
GMLAN Device (See: Powertrain Management/Computers and Control Systems/Information Bus/Testing and Inspection/Symptom Related
Diagnostic Procedures/Scan Tool Does Not Communicate with High Speed GMLAN Device).
Reference Information
Schematic Reference
Data Communication Schematics (See: Powertrain Management/Computers and Control Systems/Information Bus/Diagrams/Electrical Diagrams)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views/Connector End Views By Name)
Description and Operation
Data Link Communications Description and Operation (See: Powertrain Management/Computers and Control Systems/Information
Bus/Description and Operation)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Scan Tool References
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
