Preamble
I was looking at a 2009 Land Rover LR3 over the weekend with the OBD Fusion app.
The vehicle had no CEL issues; this was more about thoroughly inspecting a prospective purchase.
I can't remember what protocol was used to connect to the vehicle, but there was no option to view "O2 Sensor 1 Voltage" for either bank - that's the pre-cat sensor.
However, the equivalent wideband PIDs were available for both current and voltage, and I observed they responded to changes in throttle.
This leads me to believe that the LR3 has wideband pre-cat sensors.
What baffled me were the fuel trims
- Short term fuel trims hovered around +7-8% for both banks regardless of throttle position. Those really should be zero.
- Long term fuel trims didn't budge from 0% for both banks regardless of throttle position
I have used this app to log fuel trims on a Merc with widebands before, but this is weird.
Questions
- Does the 2009 Land Rover LR3 really use widebands? If no, why can't I see the PID's for pre-cat O2 voltages?
- What OBD-II protocol should the app be using to connect to the vehicle?
- Does anyone have similar experience with questionable fuel trim data?
