Topic: Fuel Sensor -Trucks keep having fuel theft and fillings-pls help
I have a very serous issue with my Analog Fuel sensors installed. Almost all the Medium to Heavy duty cargo trucks have the same issue.
Randomly the fuel level drops and rises hence triggering a fuel theft of fuel filling . Some times the thefts showing are in the range of 5 to 12 liters on some trucks 11 to 25 liters. For our customers we need to set the fuel theft detection to at least 6 liters, as mostly the drivers will not steel more than that at a time.
In this message i will put forth data and setting of one such truck.. Hopefully some one can help us figure out how to solve this issue.
Truck DT-5j-xxxx has had around 9 theft in last month as shown in table. If we examine the fuel theft o 12.5 liters on the 15th-05-2016 item number 6 on the table we can get the following graphs.
On the 1st graph( Fuel level vs ignition and trips) it can be seen that when ignition goes off at 21:32 the fuel sensor data falls. This seems to be common in all the thefts. Further more if you look at the second graph (Fuel Level VS Ext Battery Voltage ) you can see that the 24 v batter voltage fluctuates around 2 volts at same time as the ignition off time. 21:32 ...
I am very confused and not sure if the battery is causing this problem or not. Maybe the fluctuation in the battery is causing the data to change but if thats the case the data should return to normal immediately once the fluctuation has stopped.
last one is raw data of Ext Bat and Fuel Level. blue line is Fuel level and the green is the ext bat..