Basic Operation; Illustration Of Candi Module Showing Wiring - GMC Tech2 User Manual

General Motors Tech2 User Guide

Illustration of CANdi module showing wiring

Basic Operation

The CANdi is an in-line cable module that works with existing Tech2 components including
the VCI, cables and adapters. Installed, the CANdi module is fully compatible with current
and past Tech2 software. The module powers up in a way that makes it transparent to the
user. This allows the existing Tech2 software to be used with no changes when the CANdi
module is installed. If a vehicle requires the use of a CANdi module, the Tech2 will enable
features specific to the module.
The primary function of the CANdi module is to add CAN (controller area network)
capability to the Tech2. The following list summarizes the basic characteristics of the
CANdi module:
Supports simultaneous communications on three CAN buses
Provides high-speed UART communications with the Tech2
The Tech2 controls CANdi module operation. When installed, the CANdi module does not
interfere with any diagnostic procedure currently performed by the Tech2. Use of the
module does not require any physical changes to the Tech2, cables, or adapters. The
module operates transparently until activated by the Tech2. Upon activation, the CANdi
module operates under control of the Tech2. Tech2 application software loaded on the
Tech2 PCMCIA card determines all functionality.
IMPORTANT: When functioning properly the CANdi's LED will flash. If a problem occurs,
the LED will be constantly illuminated. If the module's light is constantly illuminated, refer to
the troubleshooting section in this manual.
142