LR3 (LA) V8-4.4L (2009)
Fuel Injector: Description and Operation
Fuel Injectors
Description
The injector monitor operates on a continuous basis. Open and short detection of each injector is possible by comparing the actual injection signal with a
target injection signal. The actual injection signal is derived from a change in injector voltage when the injector is turned off and the target injection
signal is derived from an injection set flag.
A normal judgement is made when the injector voltage moves from the on to off position i.e. on the signal edge. If the target signal and the actual signal
are both set to one, a normal judgement is made. This process is repeated for each injector in firing order. A failure judgement is made when no injector
signal edge is detected i.e. no change in voltage but the injector has been triggered.