Update on my TPMS woes. Reversed out onto our wee road and paused for a moment to reset the system (all tyres correctly pressured) - I did this so the car would be moving forward whilst it registered the new rotational values. The warning light went out, hurrah! Drove out to the Pizza Express on the edge of town (half way meeting point for us and the boys with their families) Happily no light showing! Unfortunately wee our grandaughter was sick half way through the meal (impressed us all by making it to the loos so no mess to clean up, well done girl!) so, looking white as a sheet, she went home with her mum in their car leaving me to drive my son and his wee lad back out to their house in Midlothian when we'd all finished. Foul weather with rain sleet and snow so the car is now absolutely filthy again and it's due at the garage tomorrow morning at 08.00hrs for MOT. Weather tomorrow is forecast to be fine so I'm resolved to get up at first light and, if it's dry, I'll give it a quick hose down and wipe off with my noodle mit. Very pleased to be able to report the TPMS light is behaving itself. I'm still puzzled as to why it lit up though - please just stay off until after the MOT tomorrow. I'm not actually sure if it would fail for showing the tyre pressure light?
The slightly different diameters do seem to annoy the TPMS system on the Citroën.
There's only 0.5mm between the older rear and the new rear and the damn thing still went off after a motorway section 4 days after the tyres had been switched and pressures checked and reset.
If anything I wonder if the new one was slightly stiffer than the older one as after 3 false pressure warnings over about the first 100 miles it's not recurred.
If you reset the system before you go in it's unlikely to do anything during the mot itself, it won't have had time to make it's measurements etc.
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