300 SRT-8 V8-6.1L (2008)
Fuel Gauge Sender: Description and Operation
Operation
OPERATION
The way the pump works is as follows, fuel enters the reservoir of the driver side module. The fuel pump pumps the fuel through the filter to the
passenger side module through a supply line inside tank. The pressure regulator inside the passenger side module regulates the pressure at 58 psi. All
unused fuel that is not sent to the engine is fed through a venturi at the bottom of the passenger side module. This creates a low pressure siphoning effect
and draws fuel from the passenger side of the tank and transfers it to the drivers side tank via siphon hose inside the tank. While the vehicle is running
the fuel in the passenger side of tank is continuously transferred to the drivers side. Fuel will continue to fill the drivers side tank till it reaches the bridge
section and then start to spill over to the passenger side.
As stated above we have two fuel level senders, the reading of these senders are averaged out to give us the fuel gauge reading. When we are diagnosing
a sender concern the passenger side reading should never be higher than the Drivers side reading. It is possible, depending on fuel level and driving habit
before diagnosing, to spill fuel over to the passenger side that might indeed show a lower resistance value than the driver side.
The fuel gauge gives an indication to the vehicle operator of the level of fuel in the fuel tank. This gauge is controlled by the instrument cluster circuit
board based upon cluster programming and a hard wired input received by the cluster from the fuel level sending units on the modules in the fuel tank.
The instrument cluster continually monitors the fuel tank sending units to determine the level of fuel in the fuel tank. The cluster then sends the proper
fuel level messages to other electronic modules in the vehicle over the Controller Area Network (CAN) data bus. The fuel gauge is serviced as a unit
with the instrument cluster.
The tech needs to order the correct part when replacing, the senders, modules, and tank as all are able to be replaced individually.
