Tyre under inflation monitoring fault

[JamieLeeWV]

Hoping you guys can help.

Have a 2015 ds5, last couple of days I've been getting the attached service messages upon engine start.

'tyre under inflation monitoring fault' and 'tyre pressures not monitored' (have attached pic of both)

Could this be something to do with the battery for the pressure monitor needing replacing or?

I have no idea what kind of tyre pressure monitoring system my car uses, i cannot see the psi for each tyre on my dash, so I'm guessing it's just the standard one that monitors the pressure as opposed to each individual psi?

Anyone help me out on what I'd need here? Quick fix or a bigger job for a garage to do?

Thanks.

[GiveMeABreak]

Can you provide your VIN, so I can see which system you have as there are 2 possibilities. Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff.

[JamieLeeWV]

Can you provide your VIN, so I can see which system you have as there are 2 possibilities. Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff.

Hi vin is VF7**************[VIN obfuscated, can be read by forum staff]

[GiveMeABreak]

Ok, so you have the direct TPMS system with wheel transmitter modules.

So this warning can be for several reasons - one or more transmitters are not communicating with the TPMS ECU, which can be the battery has expired (they only last about 10 years if lucky) or the ECU has an issue, so it really needs a diagnostic to determine the specific cause.

[JamieLeeWV]

Ok, so you have the direct TPMS system with wheel transmitter modules.

So this warning can be for several reasons - one or more transmitters are not communicating with the TPMS ECU, which can be the battery has expired (they only last about 10 years if lucky) or the ECU has an issue, so it really needs a diagnostic to determine the specific cause.

Thank you. Upon having a quick look a battery replacement seems cheap enough to do and hopefully it is that, my car is almost 10 years old and the full history of paperwork I have for it on work done doesn't show any work being carried out on this.

Would something being wrong with ecu potentially be an expensive job?

[GiveMeABreak]

Until you get a diagnostic done (preferably by either the dealership or somebody that has a Lexia kit with Diagbox) to determine the actual cause, I strongly suggest you don't start replacing anything. The ECU's are pretty robust, so may be a pairing issue with the BSI or a transmitter or another reason. The transmitter modules are not supposed to opened up but replaced as they are sealed to prevent problems.

[Vic Evans]

Not trying to hijack this thread but sort of in the same vein;
Do these pressure monitoring things that screw onto tyre valves actually work & if so do they upset wheel balance?
If anyone has a good experience with 'em any recommendations?

[GiveMeABreak]

There are 3 types:

1) OEM Direct TPMS (factory fitted only), consisting of wheel transmitters / sensors, and ECU an Aerial. Providing location information of affected tyre and whether deflated or a puncture.

2) OEM Indirect TPMS (factory fitted). No sensors on the wheels. This system uses the wheel speed sensors and the ESP ECU to determine if there is low pressure or a puncture by analysing any change in the diameter of the wheels or in the physical behaviour of the tyres. Often this system does not indicate the location of the affected tyre - so will require all tyres to be checked. The system is reset by the driver using the touchscreen display / other interface every time the tyres are inflated.

3) There are aftermarket systems that consist of tyre sensors and a receiver unit inside the car that notifies the driver of a deflation.

I've used type on and 2 and yes, they do work! I've had a few notifications of a bad slow puncture and these have been very useful in avoiding damage and accidents as a result.

Regarding balancing - no the OEM TPMS sensors do not interfere as they are factory fitted to the inside of the wheel and normal wheel balancing when tyres are changed eliminates this. Obviously for option 2 there are no sensors to worry about, and for option 3 there are various systems - either a wheel sensor like the OEM can be fitted , or some systems use a sensor in the wheel valve cap, but again will be taken into account with any wheel balancing as normal.

[Vic Evans]

Cheers Marc but I meant this sort of thing;
https://www.amazon.fr/Inoxydable-Indica ... d_source=1

[GiveMeABreak]

Oh, that's not a TPMS.

That's just a visual guide - and I have no idea how accurate those are sorry, but not much good when you're driving - only for a visual check before and after.

[Vic Evans]

Oh, that's not a TPMS.

That's just a visual guide - and I have no idea how accurate those are sorry, but not much good when you're driving - only for a visual check before and after.

I was thinking they might help my Missus as she's no idea if her tyres are suitably inflated until I have to rescue her with a flat tyre she's driven a fair way on & ruined .
Just thought I might be able to convince her to do a quick walk around before driving off.
Hoped maybe someone here might have tried 'em.

[JamieLeeWV]

Until you get a diagnostic done (preferably by either the dealership or somebody that has a Lexia kit with Diagbox) to determine the actual cause, I strongly suggest you don't start replacing anything. The ECU's are pretty robust, so may be a pairing issue with the BSI or a transmitter or another reason. The transmitter modules are not supposed to opened up but replaced as they are sealed to prevent problems.

Thanks for this sorry for the late reply..

Just like to add that although I haven't had the issue tested yet, it's seem to be intermittent. For example, the last few days it hasn't come on upon car start, only after 10-20 mins of driving.

But then some other days it came on right away? Could this be a sign of the battery wearing out and needing replacing?

[GiveMeABreak]

So the vehicle is exactly 10 years old on 12th November. The batteries in the transmitters are designed to last for at least 10 years, so it may be that one or more is starting to fail - but can't say for sure. A diagnostic would provide one or more fault codes - so if you get a chance to retrieve those when you have had time, pop them up here.

The trouble is the battery can't really be easily replaced - the sensor is glued onto the inner part of the tyre and the innards are cased in resin. They are designed to be replaced after the service life and without knowing which sensor it is (if any) you wouldn't know which sensor is faulty - but again it may be another issue totally - hence the need for a diagnostic.

[JamieLeeWV]

Until you get a diagnostic done (preferably by either the dealership or somebody that has a Lexia kit with Diagbox) to determine the actual cause, I strongly suggest you don't start replacing anything. The ECU's are pretty robust, so may be a pairing issue with the BSI or a transmitter or another reason. The transmitter modules are not supposed to opened up but replaced as they are sealed to prevent problems.

Apologies for the late reply again, I've had a hectic few weeks.

Ok, so the issues seems to be on permanently now, I was going to get a fault code reader off of Amazon, I see you mentioned lexia kit, can I use any fault code reader or does it need to be a specific one?

Gonna get one ordered today and see what the issue says.

[PaulC5]

You will need to get a code reader that says it does TPMS on a Citroen but it may not be cheap. The low cost readers usually just do engine fault codes that can affect the emissions and put the engine management light on.