F 350 4WD Super Duty V10-6.8L VIN Z Bi-Fuel (2001)
P1640 - P1644: Testing and Inspection
P1640
For diagnosis of code P1640 refer to chart
P1518 - P1781
NOTE 13: Retrieve DTC's from Bi-Fuel Secondary Module. See: Powertrain Management/Computers and Control Systems/Testing and
Inspection/Reading and Clearing Diagnostic Trouble Codes/Bi-Fuel Models (Bi-Fuel/CNG System)/Reading Diagnostic Trouble Codes