2010 Cadillac Truck SRX FWD V6-3.0L Page 2181
Action Taken When the DTC Sets
The module uses a default value for the missing parameters.
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.
Diagnostic Aids
* Use the DTC Descriptor list above to determine the module which is not communicating.
* If there are multiple non-communicating modules choose the one closest to the data link connector (DLC).
* Use Data Link References (See: Powertrain Management/Computers and Control Systems/Information Bus/Testing and Inspection/Initial
Inspection and Diagnostic Overview) to determine if the module uses high or low speed GMLAN serial data communications
* Some modules may not have internal protection for specific voltage outputs and may open a battery positive voltage or ignition voltage
source fuse. If a voltage input fuse is open and no short is found in that circuit, ensure that no module output voltage circuit is shorted to
ground before replacing the module.
* This diagnostic can be used for any module that should communicate with high or low speed GMLAN serial data providing the vehicle is
equipped with the option that uses that module.
Reference Information
* Data Communication Schematics (See: Powertrain Management/Computers and Control Systems/Information Bus/Diagrams/Electrical
Diagrams)
* Control Module References (See: Testing and Inspection/Programming and Relearning)
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
Circuit/System Testing
Note: If more than one module is not communicating use Data Communication Schematics (See: Powertrain Management/Computers and
Control Systems/Information Bus/Diagrams/Electrical Diagrams) to determine which module is closest to the DLC. Start diagnostics with that
module.
Terminal and connector identifiers will be different depending on the individual module being tested. Use Schematic Reference and Connector End
View Reference to determine which connector and terminal to access.
1. Using the DTC Descriptor and Diagnostic Aids, determine the module that is not communicating that should be tested.
2. Ignition OFF, disconnect the harness connector of the module that is not communicating.
3. Test for less than 2 ohms between the module ground circuits and ground.
瀚慖f greater than specified range, test the ground circuit for an open/high resistance.
Note: Only the high speed GMLAN modules have a wired serial data wake up circuit. Refer to the module schematics to identify which
modules have a wake up circuit. If the module that is not communicating does not have a serial data wake up circuit, proceed to step 5.
4. Ignition ON, verify that a test lamp illuminates between the high speed GMLAN serial data wake up circuit OR the accessory wake up serial
data circuit and ground.
