Component Inspection

Check CAN communication waveform
1. Ignition "OFF"
2. Connect 2 channel scope to terminal 41 (CAN HIGH) and 42 (CAN LOW) of PCM harness connector respectively.
3. Ignition "ON" after connecting only PCM to CAN BUS.
4. Ignition "ON" after connecting only ABS or ESP module to CAN BUS
  
  Fig 1: Checking CAN Communication Waveform
  Courtesy of HYUNDAI MOTOR CO.
  
  Specification : At Ignition "ON", the waveform same as "Signal Waveform & Data" of above signal waveform, Different from "Signal Waveform & Data", if 1) both CAN HIGH and LOW signal are fixed at 2.5 V or. 2) HIGH and LOW signal are fixed at 3.5 V and 1.5 V, respectively, it is due to communication error.
5. Does correct waveform generate from each module?
  YES
  - Go to "VERIFICATION OF VEHICLE REPAIR ".
  NO
  - Replace the module which generates poor communication waveform, and go to "VERIFICATION OF VEHICLE REPAIR ".