General Information

Head Unit

U1970 Multimedia CAN Bus Off Error - General Information

Component Location





General Description

MM (MultiMedia) CAN is composed of DATC (Air conditioner), Head unit, Media Unit (USB or i-Pod) and Rear Armrest Control. CAN is a communication system which consists of CAN_high line and CAN_low line to share system information between related control units (modules).

DTC Description

This code is set when each unit set CAN BUS OFF and can not send message any more.

DTC Detecting Condition





Diagnostic Circuit Diagram





Signal Waveform & Data








FIG.1) Normal MM High CAN signal waveform while one input signal is given at armrest control switch of rear seat (measured waveform signal at MM High CAN line of head unit)
FIG.2) Normal MM Low CAN signal waveform while one input signal is given at armrest control switch of rear seat (measured waveform signal at MM Low CAN line of head unit)