2010 Cadillac Truck SRX FWD V6-3.0L Page 2180

2010 Cadillac Truck SRX FWD V6-3.0L Page 2180

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.

Diagnostic Aids

* Diagnosis of this DTC is accomplished via the symptom or an additional DTC. Refer to Symptoms - Data Communications (See:

Powertrain Management/Computers and Control Systems/Information Bus/Testing and Inspection/Symptom Related Diagnostic

Procedures/Symptoms - Data Communications) or DTC U0100-U02FF (See: U Code Charts/U0100).

* An intermittent condition is likely to be caused by a short on the GMLAN serial data circuits. Use the DTC U0100-U02FF (See: U Code

Charts/U0100) procedure in order to isolate an intermittent condition.

U2105

DTC U2105-U2199

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using the 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.

Diagnostic Fault Information

Circuit/System Description

Modules connected to the high and low 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. Each message contains the identification number of the

transmitter module.

The body control module (BCM) activates the high speed GMLAN serial data wake up and the accessory wake up serial data circuits by applying

voltage when the ignition key is in ACC, ON or START. The high speed GMLAN serial data wake up circuit wakes up the electronic brake control

module (EBCM) for bus communication and the accessory wake up serial data circuit wakes up the engine control module (ECM) and transmission

control module (TCM).

Conditions for Running the DTC

* The system voltage is between 9-16 volts.

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

Conditions for Setting the DTC

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