Diagnosis Procedure

When "CAN Communication Bus Off" is detected in any control modules, or when it is not possible to communicate with any control modules by using SUZUKI scan tool (SUZUKI SDT), perform inspection using the following procedure.

1. Connect SUZUKI scan tool (SUZUKI SDT) and have DTC of ECM displayed to check for communication with ECM. If scan tool fails to communicate with ECM, check SUZUKI scan tool and communication cable, DLC power and ground circuit.

   If communication is in good condition, proceed on to next Step.

2. Using oscilloscope or oscilloscope function of SUZUKI scan tool (SUZUKI SDT), observe both CAN High terminal (1) and CAN Low terminal (2) for CAN communication signal waveform at DLC on the following condition when ignition switch is at ON position.
   MEASURING CONDITION
   
   

   Measurement terminal	CH1: CAN High terminal (1) to DLC ground terminal (3) CH2: CAN Low terminal (2) to DLC ground terminal (3)
   Oscilloscope setting	CH1: 1 V/DIV, CH2: 1 V/DIV TIME: 5 ms/DIV
   Measurement condition	Ignition switch turned ON

   Fig 1: Identifying Data Link Connector Terminals

   Courtesy of SUZUKI OF AMERICA CORP.
3. Compare observed signal waveform and waveforms given as Reference Waveform . Find the most similar signal waveform and identify the trouble system and trouble nature of the applicable "Reference Waveform".
4. Based on identified trouble system and trouble nature, perform troubleshooting according to TROUBLESHOOTING (ADVANCED AIR BAG MODEL)  or TROUBLESHOOTING (NON-ADVANCED AIR BAG MODEL) .