Topdon AL500B Manuel De L'utilisateur page 16

● The method of ignition varies by vehicle model. Please
refer to the service manual.
Figure 3.1.4
5. When the scan tool is properly connected to the DLC, the
units will start initializing and present you with the main
menu interface. (See Figure 3.1.6)
The Procedure of DTC Retrieval
1. Once you've entered the OBD-II function, the scan tool
automatically communicates with the on-board computer
to determine the communication protocol. After it's
confirmed, the link is established. (See Figure 3.2.1)
● A PROTOCOL is a set of rules and procedures for
regulating data transmission between vehicles, and
testing equipment. Here are the five different types of
protocols (ISO 9141, Keyword 2000, J1850 PWM, J1850
VPW and CAN) that are used by vehicle manufacturers.
Figure 3.1.6
Figure 3.1.5