[Yorks Jon]

Afternoon folks, I'm new to the brand after many years of VAG/other German brand ownership. I collected my 2016 i30 Crdi Blue Drive Nav SE from the dealer this week - it's fantastic and drives great but the TPMS light came on yesterday whilst driving to work, telling me that the rear N/S tyre was of low pressure. I checked it, it was fine but the light remains illuminated on the dash with the little car graphic showing left N/S trye still of low pressure. The dealer, who was very helpful, suggested I remove some air from the tyre then top it up again whilst ignition still on then go for a drive and it should clear. I have tried it but the message is still there. Sales person said he would speak to the mechanics on Monday.

Any suggestions? I'm not too concerned but it's just annoying that I can't simply press a button to reset it! Thanks for looking.....

[Surferdude]

I'm guessing the tpms valve itself might be faulty.
In any case I'm pretty sure we've established before that having the tpms light on is an MOT fail in the UK.
So it needs to be fixed.

[TerryT]

Two things come to mind.  One is that you have a faulty TPMS sensor (as mentioned above by Surferdude) OR the non-replaceable TPMS sensor battery is too low. 

Being a 2016 model, the sensor battery is about 6 years-old (plus whatever shelf life before being fitted to the sensor) so that is a possibility.  I've heard typical battery life can be 5~10 years but I guess that depends on the quality of the battery.  Mind you, if your car's service history shows that the oem TPMS sensors have been replaced that reduces the possibility of it being a battery problem...but not entirely! (Faulty or a cheap batch).

A well-equipped workshop or tyre specialist should have a quality TPMS service tool that they can run over the four tyres for a quick health-check of the sensors.   See service tool screenshot [below] of a vehicle with four good sensors fitted.

I believe if the TPMS sensor is stuffed, it will not transmit an ID number in the ID column for that tyre.   And, if the sensor battery is stuffed, the battery column will show a FAIL for that tyre.
 

My ATEQ VT-56 TPMS Tool

That's all I've got.  I look forward to hearing what the "mechanic" says. 

[BrendanP]

I'm not sure how the TPMS resets itself. I have a 2015 diesel with the skinny 15"  tyres working at 36 PSI, but I guess the sensor is the same as if I had the 16" wheels and 32 PSI. If the sensor detects a tyre change and zero pressure, then you have to drive it for a while afterwards for the warning light to go out, the ECU then takes that pressure as the correct value, and the system triggers a warning if the pressure falls a certain % below the nominal value. I had all the tyres changed at a well-known chain and they over-inflated the tyres to about 40 PSI. When I later reduced the pressure to the correct value, the low pressure alarm came on. What I had to do was deflate all of the tyres, re-inflate to the right pressure, drive it for a few miles until the light went off, and it's been fine ever since. Apart from the time when I had a genuine slow puncture, and it would detect this at about 31 PSI.

I'm not looking forward to changing all the sensors just because the batteries have died. If the manufacturers don't make the batteries replaceable then they ought to be forced to offer a 10-year warranty on them.

[TerryT]

I'm not looking forward to changing all the sensors just because the batteries have died. If the manufacturers don't make the batteries replaceable then they ought to be forced to offer a 10-year warranty on them.

I wish!!