Dear Mr. Prasert,
Thank you for your information. I have received your e-mail and forwarded the BITE test immediately to a technician for review. Unfortunately he has not contacted me back yet. Anyway in the meantime you could check for the incoming and outgoing power to and from the interface box. Do have a spare Interface box?
On the 7 pin CAN Bus cable your power should be between pin 2 and 3. 24V
On the exit cable going in to the MK20 you should measure 24V between A and B