Fuel Tank Pressure Graphing
Connect scan tool. Select PID/DATA MONITOR AND RECORD function. Select CDCV and FTP PIDs. Press start. Perform drive mode 4. Press TRIGGER when starting drive mode. Monitor CDCV PID. When PCM monitors EVAP system, PID will change from OFF to ON. After test is complete, PID will change to OFF. Wait a few seconds, then press TRIGGER. Select VIEW RECORDING and press TRIGGER. Select CDCV and FTP PIDs. Press GRAPH. Use No. 8 key to advance to point when CDCV was turned on. Compare graph to normal and abnormal patterns. See Fig 1 . Diagnose and repair as necessary.