C4 TPMS

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gosnoid72
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C4 TPMS

Post by gosnoid72 »

I had my front tyres changed today and I queried why they didn't replace the valves. Apparently I've got TPMS fitted? So my question is how does it work on a 54 plate C4. I understand the concept, but I was wondering if it displays somewhere of is purely a low pressure warning? Either way, neither option applies to my vehicle! :-D
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GiveMeABreak
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Re: C4 TPMS

Post by GiveMeABreak »

Your vehicle was shipped with a TPMS system from factory. So either the system has been disabled via diagnostic tool or it there is nothing wrong with your tyre pressures.

With direct TPMS (which have sensors on the wheel valves), the signal is sent to the TPMS ECU via transmitters in the sensors and aerials on the vehicle. Tyres are monitored for punctures and low pressures.

Regarding the valves. These do not need replacing each time your tyres are changed. They are a little more robust and therefore can last for 3-5 tyre changes. However at some point they may start to leak so Citroen sell a repair kit for about £5. This contains a new valve and various parts that can be replaced when necessary. The dealer can probably do this during a service.

So the tyre fitters generally know when you have TPMS sensors fitted as they have metal and not rubber valve bodies.
gosnoid72
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Joined: 25 Apr 2022, 21:43

Re: C4 TPMS

Post by gosnoid72 »

Thanks Marc, part of the reason for changing one of the tyres was a slow puncture, so I definitely know the system isn't working. Knowing the attitude of the previous owner, it is probably faulty and has been disabled. Can I check with Lexia? I need to have at least one of the valves replaced as the threads have gone and I can't screw my inflator on.
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GiveMeABreak
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Re: C4 TPMS

Post by GiveMeABreak »

You can check - run a global test and see if there is a fault coming up against the TPMS ECU after it has completed. If this is the case, then if you want to leave it disabled, you can safely get some standard tyre valves. There's not much point paying for a TPMS sensor which are quite expensive if the system has been disabled and you don't want to use it. In that scenario, I would probably replace them all - but this would involve removing all the tyres and physically removing the sensors and replacing them....
gosnoid72
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Joined: 25 Apr 2022, 21:43

Re: C4 TPMS

Post by gosnoid72 »

Thanks, I'll have check once I've got Lexia up and running.
gosnoid72
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Joined: 25 Apr 2022, 21:43

Re: C4 TPMS

Post by gosnoid72 »

OK, Lexia test complete. I have two faults on the TPMS -
TPMS Fault.jpg
I also have this -
TPMS Fault 2.jpg
TPMS Fault 2.jpg (11.34 KiB) Viewed 32 times
So to fix the the two valves with dodgy threads I can get a set of these, I assume? - https://www.ebay.co.uk/itm/324113601219 ... media=COPY

And to fix the transmitter it's one of these? - https://www.ebay.co.uk/itm/264577246919 ... media=COPY
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GiveMeABreak
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Re: C4 TPMS

Post by GiveMeABreak »

Those are the valve stem repair kits I mentioned and not the actual TPMS sensors themselves, which are fixed inside the wheel rim.

From the above, the system has been disabled which is causing the faults. It seems that the readings are inconsistent with the front right hand sensor appearing low (1.8) at one reading and then absent on the other reading. The rear left hand sensor is not being picked up, so I suspect the internal battery on that one may have failed (end of service life).

With the vehicle now over 18 years old, these have done pretty well if these are the original sensors and I suspect the previous owner couldn't be bothered to replace a failing sensor so had the system disabled.

If you re-enable it you will have warnings popping up all the time warning you about the faulty sensor (s) so you have to decide what you are going to do. Live without the system, or replace all the faulty sensors and valve kits and then have the system re-enabled - which will need all the sensors re-pairing to the ECU.
gosnoid72
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Joined: 25 Apr 2022, 21:43

Re: C4 TPMS

Post by gosnoid72 »

Thanks Mark. The issue which I currently have is with the valve stems on the front wheels, which have stripped threads, meaning that I can't screw my inflator on. The front right wheel has had a slow puncture, which may account for that message. The rear left has a traditional shaped valve stem on it, so I would imagine that was changed on the cheap, when that tyre was changed.

With regards to the second eBay link for a new sensor, are these 'plug and play' or do they need coding to the car?

I think I'll try and re-enable the system and see how I go.......
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GiveMeABreak
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Re: C4 TPMS

Post by GiveMeABreak »

I can only provide you with official PSA parts diagrams and Part numbers

If you can't already find the info you need on the Forum, we do ask for a membership upgrade for official parts data as we are in turn charged for this. It will cover you for future parts requests for up to 2 years, so excellent value.

If interested, links are below, I already have your VIN.
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gosnoid72
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Re: C4 TPMS

Post by gosnoid72 »

Cheap at half the price! (I never did get that saying!) I'll donate later when I get home. Thanks.