FLA -646
FUEL SYSTEM
SIGNAL WAVEFROM AND DATA
EFD86111
Fig.1
Fig.1) CAN communication waveform
Monitoring CAN HIGH and LOW simultaneously is important in monitoring CAN communication waveform.
When CAN HIGH signal rise to 3.5V and LOW signal drops to 1.5V - voltage difference between HIGH and LOW signal is
2V - at BUS IDLE state(DIGITAL "1") whose reference voltage is 2.5V, "0" is recognized. Besides, comparing HIGH and
LOW signal if opposite waveform is detected with the reference voltage of 2.5V, Check if current cam signal transfers
correctly.
Continuous "0"signal above 6BIT means the occurence of error in CAN communication. 1BIT is easily distinguished as
calculating the time when "SOF"(START OF FRAME) which notifies the start of frame occurs.
Check if "0"signal above 6BIT is detected continuously when monitoring CAN communication waveform.
CAN HIGH signal
CAN LOW signal
SOF Bit
Digital "0"
Digital "1"
BUS IDLE
LGLG397A
MONITOR DTC STATUS
E9EAD6E3
1.
Check DTC Status
1)
Connect scantool to Data Link Connector(DLC).
2)
IG "ON".
3)
Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC’s information from the
DTCs menu
4)
Read "DTC Status" parameter.