L322 tyre pressure (TPMS) system problems

[red-dragon]

Hi all

Having recently purchased a 2008 L322 range rover, I know relatively little about how the TPMS works and hoping you can help me debug this issue!

 

When I first purchased the vehicle, the dash readout said "check spare tyre pressure" immediately on startup.

After 50 miles or so over a couple of journeys, it then did the same on startup, but then immediately followed by "check all tyre pressures". I had a flat on the rear right tyre.

I then put a new set of tyres on the vehicle, at the correct tyre pressures, and in doing so realised there was just a standard valve stem in the spare wheel. This was then fitted with a properly coded TPMS sensor before being stowed in the boot compartment.

On the next startup, the flat tyre light illuminated and said "check spare tyre pressure" but then went out after 2 mins. I assumed this meant it had picked up the new sensor and all was well.

However, on the next two journeys it did the same thing. Although the light went out fairly quickly, surely it should only have to acknowledge the new sensor once?

Unfortunately now however on the latest journey today, the flat tyre light has not extinguished and instead says "check all tyre pressures"!

To recap:

All wheels have TPMS sensor stems (4x old/pre-existing ones in the road wheels, 1x new in the spare wheel)

All set to correct specification tyre pressures

Brand new tyres on all wheels inc spare.

Flat tyre warning light illuminated and message on startup is now "check all tyre pressures"

 

Be very grateful for advice on how I can solve this! My gut instinct was just replace all of the TPMS sensors for new but they are £50 each so it's quite an expensive process of elimination that I am well aware may not be the source of the problem!

Cheers in advance for suggestions...