Fuel Level Sensor: Description

This input is required as part of the misfire detection system in order to record if a LOW FUEL situation was present when misfire was detected and logged as a fault. On Range Rover 38A the ECM is required to read an analogue fuel level input and determine the LOW FUEL condition from this signal. Discovery Series II had an active high digital input until 2000MY, at which point this input also became an analogue signal. For fuel level sensor testing, see Fig 1 .

There are three fuel level input diagnostic checks, during which a fault is detected if:

1. The input signal is less than a minimum voltage threshold.
2. The input signal is greater than a maximum voltage threshold.
3. The percentage difference between the fuel consumption calculated by the ECM and the change in the fuel tank level is greater than a threshold.

Fig 1: Fuel Level Sensor DTC Testing

Courtesy of LAND ROVER NORTH AMERICA, INC.