Universal Asynchronous Receiver Transmitter （Uart） Data Circuit; Keyword 2000 Data Circuit; Audio Security System - Chevrolet Sail 2010 Learner’s Manual

Transmission Control Module （TCM） （UART）
Airbag Sensing and Diagnostic Module （SDM） （UART）
Anti-Theft Locking System Control Module （UART）
Anti-Theft Module （UART）
4.4.1 Universal Asynchronous Receiver Transmitter （UART） Data Circuit
The communication system based on the universal asynchronous receiver transmitter has a main serial data
circuit and a long-distance transceiver. The main serial data circuit in turn visits all the long-distance control
modules to control the information flow of the serial data circuit. The main serial data circuit then waits for
appropriate responses.
The universal asynchronous receiver transmitter （UART） serial data circuit allows the following
components to communicate with the diagnostic instrument:
Electronic Brake Control Module （EBCM）
Transmission Control Module （TCM）
Airbag Sensing and Diagnostic Module （SDM）
Anti-Theft Locking System Control Module
Anti-Theft Module
The universal asynchronous receiver transmitter （UART） serial data circuit allows the diagnostic
instrument to communicate with these modules in diagnosing and testing.

4.4.2 Keyword 2000 data circuit

The keyword protocol employs a single two-way data line between the module and the diagnostic instrument
to communicate. The message structure is a request & response arrangement. The keyword serial data is only for
the diagnosis of the diagnostic instrument. Neither module exchanges data through these systems.
Keyword 2000 Serial Data Circuit:
The Keyword 2000 serial data circuit allows the following component to communicate with the
diagnostic instrument: engine control module.
The Keyword 2000 serial data circuit allows the diagnostic instrument to communicate with the module
in diagnosing and testing.

4.5 Audio Security System

When the audio system circuit is disconnected from the accumulator, then the audio security system is
activated. A 4-digit security code must be entered in order to restore the functions of the audio system. The
security code is impressed on a card generally located inside the glove box of the vehicle.
The following security code entering procedure must be followed in order to decode the audio security
system:
1. Place the ignition switch to the ACC（accessory）position, and switch on the radio. At this time, the radio
display screen shows "CODE" accompanied with buzz.
Press the radio preset buttons 1 to 6 or 1 to 8 （if equipped） to enter the 4-digit security code.
2.
3. After being entered, these 4 digits flicker three times, and then the radio is restored to its normal
functionality.
Chevrolet 2010 New Sail New Technical Training
67
- Learner's Manual