C5-Tyre(s) Deflated warning

wheeler · Post by **wheeler** » 25 Oct 2009, 09:44

myglaren wrote:I don't have them on my C5 but I have read that on changing wheels around, especially fitting the spare, error messages can be thrown up. They seem to be somewhat random too.

The spare doesent have a sensor so it sees it as 1 sensor missing.

Post by **Paul-R** » 25 Oct 2009, 12:02

cachaciero wrote: Ah!... well it was only thought, if it works the way you say it does then I have a feeling that a low pressure signal would not be enough to cause registration, after all if it transmits on a regular basis when the tyre is good and it won't register why would it do it flat

The ECU is only open to accepting new valves when under control of the Lexia. It might be interesting to ty driving the C5 (perhaps with under pressure tyres!) and see if the Lexia can make the ECU accept the valves. The only problem is that the ECU expecys them in a certain order although on the Phase I that surely woldn't matter?

As a matter of interest my tyre fitter told me that you don't have to muck around with an exciter for hte TPMS on Renaults. You just drive away and the system sorts itself out!

cachaciero wrote: I wonder if the initiator just generates 125K hz with no embedded data...

On the C5 I am fairly sure it is unmodulated. There are some exciters which can also do a modulated 125KHz output but what modulation and for which vehicle I have no idea.

cachaciero wrote:.. if so it should be simple enough to make one.

My thoughts exactly!

One of the reasons I joined this site is that there seems a huge depth knpowledge about so many things and, when I had gathered enough information, I was going to put this very question to everyone.

I was thinking of first of all starting off with a signal generator feeding into a coil of some kind to see if that would work. Not very portable nut if it gets the job done, so what.

I have also talked with some more knowledgeable radio amateur friends of mine who have said that it should be easy to knock up a small signal generator using an IC and a handful of components. Personally I don't trust or understand anything that has more than 3 legs (a little electronics joke there).

Post by **myglaren** » 25 Oct 2009, 12:04

wheeler wrote:
myglaren wrote:I don't have them on my C5 but I have read that on changing wheels around, especially fitting the spare, error messages can be thrown up. They seem to be somewhat random too.
The spare doesent have a sensor so it sees it as 1 sensor missing.

There is that but it seems that having a deflated tyre in the boot can send the system slightly haywire.

wheeler · Post by **wheeler** » 25 Oct 2009, 20:54

The tyre in the boot should not be emitting anything & should be ignored, the inertia switch in the sensor knows the tyre is turning due to centrifugal force.

cachaciero · Post by **cachaciero** » 25 Oct 2009, 21:18

wheeler wrote:The tyre in the boot should not be emitting anything & should be ignored, the inertia switch in the sensor knows the tyre is turning due to centrifugal force.

Wheeler were did you find all this interesting info? The real 64000 $ question the batteries in these things are lifed at about 10yrs can they be replaced? even if it means a bit of cutting soldering and re-potting.

Cachaciero

cachaciero · Post by **cachaciero** » 25 Oct 2009, 21:25

Paul-R wrote:
I was thinking of first of all starting off with a signal generator feeding into a coil of some kind to see if that would work. Not very portable nut if it gets the job done, so what.

I have also talked with some more knowledgeable radio amateur friends of mine who have said that it should be easy to knock up a small signal generator using an IC and a handful of components. Personally I don't trust or understand anything that has more than 3 legs (a little electronics joke there).

A 1Mhz reference oscillator (4 legs

fed into a binary counter to divide by eight ( a few more than 4 legs

this driving a medium power transistor with a coil for a load should do it. The output waveform will not be sinusoidal but the output could be tuned to give a rough approximation although maybe a squarish pulse would be acceptable.

cachaciero

wheeler · Post by **wheeler** » 26 Oct 2009, 19:01

cachaciero wrote:
wheeler wrote:The tyre in the boot should not be emitting anything & should be ignored, the inertia switch in the sensor knows the tyre is turning due to centrifugal force.
Wheeler were did you find all this interesting info? The real 64000 $ question the batteries in these things are lifed at about 10yrs can they be replaced? even if it means a bit of cutting soldering and re-potting.

Cachaciero

I used to own a full set of C5 factory manuals.
Never tried to replace the battery, i would'nt imagine it was impossible with a bit of modification. The workings are imbedded in a resin.

dieselnutjob · Post by **dieselnutjob** » 12 May 2010, 19:06

I know this is an old topic, but I have the same problem with my 607.
Anyway there is an Atmel chip for making the 125kHz inductive signal.
see
http://www.atmel.com/dyn/resources/prod ... oc4909.pdf

Post by **Paul-R** » 12 May 2010, 21:25

Excellent link. When I'm in work tomorrow with nothing to do (!) I'm going to follow that up.

dieselnutjob · Post by **dieselnutjob** » 12 May 2010, 22:35

here's another
http://www.atmel.com/dyn/resources/prod ... oc4857.pdf

rmunns · Post by **rmunns** » 12 May 2010, 22:39

Just a personal observation from someone without such an unnecessary feature. WTF! Do people actually pay for this?

Post by **Paul-R** » 13 May 2010, 09:37

It's not a choice item for many, TPMS is now a legal requirement in the USA.

Post by **Paul-R** » 13 May 2010, 09:38

Duplicate - please delete. (Why can't I delete my own message anyway?)

dieselnutjob · Post by **dieselnutjob** » 13 May 2010, 12:21

Paul-R, I have some questions about some things that you have stated.

Reading the chip specs it seems that they have the ability to send a digital message modulated onto the 125kHz carrier. I think that we have no evidence at all that an unmodulated 125kHz carrier will cause the sensor to emit the right signal to pair it with the BSI. Finding out what digital signal these tools send would be virtually impossible if a simple 125kHz burst doesn't work. Have you any evidence that a simple RF burst will do it?

Also you say that a correctly inflated and rotating tyre will only emit a signal every 10 min or so. The thing is that if I start my car and drive down the road it complains about missing sensors within about 100 yards of my house, which seems at odds with what you say, unless they emit the signal once when they first detect rotation.

When I connect my Peugeot Planet 2000 to my 607 and select tyre pressure sensor learning it tells me to activate the sensors using Protoctair in a certain sequense. I did try jacking up the first wheel that it said and rotating it, in fact with the car in neutral it span quite quickly all by itself. The BSI did not pick up the signal. If what you are saying is true could it be as simple as making sure that the car doesn't move for ten minutes before selecting learning and then allowing the wheel to rotate?

Also I assume that the BSI is looking for a signal with a serial number during the learning process. Would it care whether the serial number comes with a forced/inflated/uninflated or flat signal? If the sensor emits a signal more often with a flat tyre why can't I just reduce the tyre below the threshold of a flat tyre and then rotate it whilst the BSI intends to learn it?

I have had one strange thing with these sensors. I had a spare wheel in the back of the car which happened to be already paired to the BSI. Driving along the motorway I suddenly got a flat tyre warning for that wheel which was on the back seat. It seems that the movement from hitting bumps and whatnot was enough to cause the sensor to transmit its status.

My early 607 has a different part number for the sensors to most other Peugeots, but I think that the same sensors might be used on C8 MPVs as well. They seem to be different to 407s though.

wheeler · Post by **wheeler** » 13 May 2010, 15:03

Operation of the emitter module:
· every minute as soon as the vehicle speed is greater than or equal
to 20 km/h,
· every 60 - 65 minutes when stationary,
· every 5 seconds maximum if the sampled pressure is abnormal.

Thats for the mk1 C5 the Mk2 uses a totally different system with a dedicated ECU.