2010 Cadillac Truck SRX FWD V6-3.0L Page 2153

2010 Cadillac Truck SRX FWD V6-3.0L Page 2153

Circuit/System Description

Modules connected to the high 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. The supervision time-out period is 250 ms. Each message

contains the identification number of the transmitter module.

Conditions for Running the DTC

* Voltage supplied to the modules is in the normal operating voltage range.

* The vehicle power mode requires serial data communication to occur.

* The DTC U0001 does not have a current status.

Conditions for Setting the DTC

A supervised periodic message that includes the transmitter module availability has not been received.

Action Taken When the DTC Sets

The module uses a default value for the missing parameter.

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.

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 Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

With a scan tool, attempt to communicate with all modules.

Circuit/System Testing

1. With a scan tool, verify DTC U0100-U0299 or U2105-U2199 is not set as current.

瀚慖f DTC is set, refer to DTC U0100-U02FF (See: U Code Charts/U0100) or DTC U2105-U2199 (See: U Code Charts/U2105).

2. Ignition OFF, test for less than 5 ohm between the applicable module ground circuit and ground.

瀚慖f greater than the specified range, test the circuit for an open/high resistance.

3. Ignition OFF, disconnect the applicable module harness connector.

4. Ignition ON, verify a test lamp illuminates between the following circuits of the applicable module and ground: