306oc - Peugeot 306 Owners Club & Forum

Over the 13 years and 300k miles of owning my 306 HDI one fault has cropped up time after time and that's P0121.

After the last time the prices had gone up now up from £70 to £134 for a new one from the dealers I thought I'd have a look at trying to fix it as it's just getting to pricey to replace all the time. The shortest time ones lasted is just over a year! I've tried the earth mod that some other forum suggest to no avail.

*edit

I have now found the real reason why my TPS was playing up and it will most likely to be the same on yours to. I use to think it was contaminated grease in the unit but it is the female connector on the plug that is to blame.

The reason why my other guide worked is because of the same reason why the wiper track clean guide works, the action of removing the plug disturbs the corrosion and does clean the contacts a little.

Even though the plugs are sealed they only have rubber gasket type seals and the angle that the TPS sits at the front of the bay lets water off the roads to sit in little puddles on the end of the connector. This water slowly makes its way in to the plug and the terminals will corrode with this moisture.

It's very difficult to see the corrosion in the plug but it's there.


The reason I found out was I bought a new TPS and I got the fault again the next day and thought I'd investigate further.

You can see here where the water will sit and get past the rubber seals.


Take the plug off and clean the terminals on the TPS.


To clean the female contacts you will need to insert something with an edge, I used a paper clip.


After cleaning the terminals I stuck some silicone on the top of the plug. Make sure you don't have any gaps and make sure you get between the cables.


Since doing the above I put the old TPS on and it has been fine for the last 6 months.

So clean the connectors on sensors or other bits that have gone wrong before changing them. I did the same on the wiper motor when that stopped self parking. The wiper motor connector doesn't even have a gasket between the motor and body connectors.

Below is how to change the grease on the TPS if you really want to but I think that is a waste of time.


All this repair involves is taking the TPS a part, clean out the old grease and replace with new, so very simple.

The first time I did this was over a year ago and I've not done it again since. I'm guessing the clean out has sorted it.

Remove the TPS from the car.



Lay the TPS flat on the bench.



Using a thin flat screw driver pull out the glue out two of the heads of the screws.





Unscrew the screw out to release the sensor from the body of the cable holder. Then unscrew the three torx screws on the sensor module.







Carefully lift out the top. There is a spring behind the top.



Lift out the centre.



Clean off all the grease and in the nooks and on the centre of the body of the centre as well.



Regrease and reassemble.



There is a bit of a knack to get the spring back into position and just be patient.



Replace the three screws.



Reassemble the unit by placing the sensor module back on to the cable body.



Screw the two back together.

Now the unit should work as it should unless there was something else wrong with it. For a free fix this is worth trying before forking out on a new unit.

I've done this guide from memory and I will be taking a spare a part soon so I can add a bit more detail to this thread in the next couple of days.

I hope this help someone out there.

Before starting the car it will be worth using OBD tool to check that the sensor goes through it's range smoothly with out any jumps in the amount of throttle applied.

Good luck and let me know how you get on.

Thanks for posting the guide

Useful to know as mine throws this fault each year. I find though, that in my case the plug itself is the problem as it's full of green furry deposits - same for the fans plug.

I shall do this on my brothers car next time as his keeps throwing the same fault.

havent had a problem with mine but good to see this guide is here in case i ever need it!

It primarily affects high milers due to heavy use in wet conditions, as it is right behind the grille.

This is what I thought and the heat soak off the rad.

On the 406 its located near the battery, out the way from heat and spray.

I was wondering about the location. May look into moving mine or even finding a pedal with it incorporated into the unit. No cable!!

(19-01-2013, 09:19 PM)Jonny81191 Wrote: [ -> ]I was wondering about the location. May look into moving mine or even finding a pedal with it incorporated into the unit. No cable!!

307 one is like that but there is loads of different types on servicebox so good luck finding one that is correct for your car and fits!

I was kinda thinking floor mounted pedal as well.. I wonder if i could make up a unit using a beemer floor mounted pedal with a short cable to the standard TPS mounted above it.

personally i hate floor hinged pedals. The one in the skoda is like that and it causes cramp in your ankle after long journeys. Sounds stupid but i dont get it in any other car with a normal pedal.

Could keep the 306 pedal, mount the TPS above the pedal behind the dash and chop the cable right down? should also make the pedal a fair bit lighter seeing as its not so much of a run?

Today when I started my hdi the revs hung at 1100rpm and it did this for about 2 minutes then when I drove it a minute or to the revs dropped back to normal idle again. Is this likely to be the tps?

It sounds like it could be. If it is it'll happen more and more then the ELM light will come up. If it does and the code P0121 the it's definitely the TPS.

Try cleaning it out or if there is a breakers with a 406 hdi or 206 1.6 xsi get the TPS off that as there out the way from heat and spray.

Just want to say thanks for the guide!!
I did the earth mod too!!! did not cure!!!
Checked the wiring! no issues!!!! other than it on my 3 plug ECU didnt match the wiring diagrams i was able to find!
followed this guide! and bingo!!! after i cleared the faults on the ecu. it didnt come back. Many thanks!!

Jeremy

Glad it helped.

The sensor is now £335!!! I don't know how they can hike the price so much, f*cking bastards.

How much!? You can buy a whole HDi for that these days!

The thing is this is a common part found on a lot of pugs. I could understand a little if it was a 306 hdi specific part but it's not.

Hmm, I can only assume they've changed it in some way after recognising they were failing, possibly made it more accurate or longer lasting... Still no reason for such a huge price on what is a pretty simple sensor though!!

It usually says on service box if there has been any changes and they only seem to fail more often on the 306 HDI.

It's never caused problems on my dads 406 hdi, my girlfriends 206 hdi and my friends 206 xsi 1.6 petrol car.

What kind of grease would i need to replace it with?
Probably a dumb question lol

(07-05-2014, 01:59 PM)Strikeforce Wrote: [ -> ]What kind of grease would i need to replace it with?
Probably a dumb question lol

I was thinking the same

I've used white grease

(07-05-2014, 07:43 PM)JamesG Wrote: [ -> ]I've used white grease

Cheers ill try some of that

(07-05-2014, 01:59 PM)Strikeforce Wrote: [ -> ]What kind of grease would i need to replace it with?
Probably a dumb question lol

I used silicon grease but the tps issue came back a couple if weeks ago so I have tried lithium this time.

Silicone/white grease is the same thing and is like porridge, better off with something a bit smoother, lithium will most likely be fine.

this is nice i have a few here, will try it out

Good news guys the price has come down slightly for the TPS from the dealers. It's now at £281 lol

But there is someone on eBay selling new ones for £90. http://www.ebay.co.uk/itm/PEUGEOT-206-30...1069960268?

The one at the dealers is a 1920X1 but the one on eBay is 1920AK, I wonder what the difference is?

Anyway I found a good thread on someone's issue with P0121 http://www.honestjohn.co.uk/forum/post/i...m?t=100155
It's interesting to here that his was a wiring issue rather than the sensor. I'm thinking there must be a wiring issue causing mine to go so frequently?

Updated post

Nice one Dee, I'll check mine out

(07-05-2014, 07:43 PM)JamesG Wrote: [ -> ]I've used white grease

would Vaselene suffice?

Try cleaning the connectors first before taking the unit a part. I've sorted two cars just by cleaning the connectors.