This waveform is measured between terminals CANH and GND, and terminals CANL and GND of the DLC3.
(Use this as a reference for diagnosis of CAN communication lines.)
When malfunctions in multiple ECUs are suspected based on the CAN bus check and DTCs checked using the
Techstream, check the resistance of the CAN bus using an ohmmeter first . If no problems are found,
check the following waveforms.
If a waveform is not similar to one of the following 3 patterns (Group 1), then an open in a CAN main bus
line, an open in a CAN branch line, or a short between a CAN line (CANH or CANL) and ground is suspected
Wiggle the connector and wire harness to check if the waveform changes.
(a) CAN bus waveforms (Group 1)