User Manual

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7.4 OBDII CAN Bus Check
OBDII CAN Bus Check is an instrument that detects the communication status of CAN
Bus. When the VCMI (Vehicle Communication and Measurement Interface) device is
connected with MaxiSys MS919 Tablet, you can open the OBDII CAN Bus Check
application by taping the Measurement icon on the Home screen of the tablet and then
tapping the OBD icon, and perform the OBD-related functions including the signal
detection. The indicator light flashes if the signals are detected. The indicator light
displays in gray if no signal is detected.
Generally, the vehicle's electronic control systems are designed to comply with the
specific communication protocols. The control units in the electronic control systems
communicate with the Tablet through the OBDII (DLC) adapter.
With the OBDII CAN Bus Check function, you can check whether the control units in
vehicle's electronic control systems work properly or not with the indicator light according
to the condition of sending out the communication signals.
7.4.1 Safety Information
Follow the instructions below to ensure proper CAN Bus check performance.
 Different preconditions for different functions. Before check, please read the
inspection guides carefully.
 The pin number for OBDII varies by vehicle modes. Please check and confirm for
correct pin number and then proceed inspection.
 Select OBDII connector's signal pins manually if the test vehicle's actual
communication signal pins are assigned differently.
 Ensure the DLC main cable is connected to the vehicle before inspection.
 Ensure the ignition key is in ON position when testing the vehicle's communication
line.
 If the inspection fails due to no signal input, consult vehicle circuit diagram to ensure
correct communications are being tested.
 Do not use in wet or damp conditions, or around explosive gas or vapor.
 Do not tamper with or disassemble the product, connectors or accessories. Internal
damage will affect performance.
 Disconnect the product from power source, vehicle and tablet before cleaning.
 When cleaning the product, use a damp, soft cloth with mild detergent. Do not allow
water to enter the product casing, as this will cause damage to the electronics inside.