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 control module to CAN BUS.
  
  Fig 1: Signal Waveform Graph
  Courtesy of KIA MOTORS AMERICA, INC.
  
  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 between modules.
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 ".