2 fault codes. Help

[LiamR172]

Hi all..

Im having problems with the clio going into limp mode, ive had it plugged in and its coming up with 2 faults.

Can anyone tell me what they are and where the parts are on the car so i can fix it.

Ive got a trackday on friday so ideally needing it fixed before then! Not much use going round a track in limp mode

throttle potentiometer fault

Bi-mode air solenoid valve

Its a phase 2 172.

Thanks!

 

[Djw John]

First one sounds like throttle body or pedal to me. But no expert on phase 2s.

Second one the only thing I can think of is have you removed the acoustic valve? Iirc you have an induction kit so you probably have!

 

[LiamR172]

From what i can see on google, it seems to be something to do with the signal from the throttle pedal to the throttle body.

Or is that what a throttle position sensor does do you know?

I do have an induction kit but the acoustic valve is still in place. Although the last time i seen it, it has already been tampered with so maybe its not working properly.

 

[Djw John]

The pedal is only a few minutes to change. So is the tb, doesn't your bro have a 172? Borrow each part one at a time and see what cures it.

 

[LiamR172]

He has a 182, but hes not here just now so i cant do that.

Ive bought a TB but its not arrived yet, is the pedal just torx or something? And the 1 plug in the top of it?

 

[Djw John]

Yeah just the one plug. Iirc it was 3 10mm nuts but its been a while. Doesn't take long.

 

[Fraser.J.]

I've got a pedal if you need it

 

[LiamR172]

Thanks Fraser, ill see if i can find out 100% whats causing it, if its the pedal ill get it off you on friday?

 

[MicKPM]

Need to ser the data Liam. You at Bedford as I can scope the tracks for you and tell you if its a pedal or not?

I've changed one today on a 172 but its rare that these faults are *actually* due to the pedal (normally its age vs corrosion)

Mick

 

[LiamR172]

I live in Inverness Mick

Is there anything i could check myself?

This is what the diagnostics computer said today..

 

[mjm3043]

You want try the pedal of mine to see if its that?

 

[LiamR172]

Thanks for the offer mike, are you about tomorrow at all?

Btw, Mike was wanting to speak to you about knockhill.

Pm me your number?

 

[MicKPM]

It will be the difference between tracks 1 & 2 that's causing the reduction in engine speed and I will put money on it being neither the pedal or the throttle body. In fact, I'll go all out and say even money on it being a wiring fault in the engine bay loom section.

 

[LiamR172]

Makes sense Mick, i did mail you on Facebook the other day about the problem.

First thing i noticed was a HT lead was broken, so i got a set of leads.

When changing the leads i noticed the inlet gasket was knackered so i got one and fitted that, when i fitted that i noticed the wiring going to the coilpack was damaged, the orange wire had melted and some of the strands had actually snapped.

So, ive replaced the leads, gasket, tried a different coilpack and i cut the bad bit of wire out and rejoined it with some connectors.

I had a good look at all the other wiring around that area but i couldnt see any other damage.

Do you have any ideas where i should check?

Thanks for the help!

Edit- this is the wire im talking about, not the best photos sorry.

 

[.GAZ.]

Can you not buy that length of wire from someone that's breaking one? Speak to Fraser.

 

[LiamR172]

I could do aye..

Anyone know how i could change it?

I know bugger all about mechanics and even less about wiring :l

 

[MicKPM]

I don't monitor the facebook page as I'm normally battling emails as well as actual work. Chances of an ignition coil loom causing a tp track consistency issue are slim.

Ideally you need a scope now to graph the two signals in real time as that will show any errors (if one actually exists). I suspect that, unless it's a Cup, it'll be somewhere near the ECU connector.

 

[LiamR172]

Sorry Mick i dont know what you mean by 'scope' ?

And no its just a normal 172.

Thanks.

 

[MicKPM]

"Scope" or "DSO" aka "oscilloscope"

Basically it turns the numerical sensor values read by the ECU every millisecond in to a pretty moving line type picture (Known as a waveform) which helps better understand any problems which may occur.

Normally a very pricey piece of kit which even some large workshops don't have access to let alone DIY/Enthusiasts. I take my dual channel mini-DSO with me everywhere (Seriously, ask the wife as she thinks i'm nuts) so if you were at Bedford on Friday (Which I don't think you are) i'd offer to scope it for you.

 

[LiamR172]

b****cks!

What else can i do then? As theres no chance ill be able to get anyone to do that for me

 

[MicKPM]

These cable-less systems basically consists of two potentiometers which are essentially a kind of scaletrix controller. They normally read in mV but this is seen by the ECU as a percentage - Typically One starts at 0% and ranges to 100% and the other starts at 100% and ranges down to 0% (Although some systems both range from 0-100%).

SO if you were cruising at part throttle... say 17%, one track would report a value of 17 and the other would read 83. Add them together and you get 100 so the ECU knows it can safely actuate the throttle plate. Now the system has a built in safety measure that is constantly checking the maths and if something is wrong (Or out of a pre-set tolerance), rather than send you in to a wall at 83% throttle it limits the engines output and restricts the throttle plates maximum angle to some very low/slow boring angle like 9%. If a problem is detected a generic code is raised and logged in the EODB which in this case would be "Inconsistency between pedal tracks 1 & 2".

Most garages are quick to interpret this code reading session as "Replace the pedal" but unless you scope the signals and confirm that both tracks are indeed inconsistent then chances are they're wasting cash. In my experience with these issues on non-Cup X65's its almost always wiring in the engine bay loom close to the ECU that causes this problem.

 

[MG cup]

Mick could he not continuity check the associated loom if its easily accessible, that's something that a home mechanic should manage with basic tools.

When you mention cups, are there not many engine loom faults on these?

 

[LiamR172]

Thank you for explaining it Mick.

Could i use a bit of loom from a cup to replace mine?

 

[LiamR172]

Also, if i can use a bit of cup wiring, do you know which part(s) i would need to replace?

 

[MicKPM]

Prob not chap - Continuity testing will only show if there's a clear "break" in a line which if there is an *actual* "difference between tracks 1 & 2" it most likely won't have (backed up further more by the diagnostics not saying something like "Throttle potentiometer Track 1/2 - Open Circuit" which it would if there were a broken wire).

I agree that continuity testing is something that most semi-competent people can do themselves but you have to remember how *most* automotive electrical wiring is produced. Unlike domestic "single cores" automotive wiring is made up of 7/9/14/24+ individual strands of wire which is twisted into a single core. Say 98% of the wires core has broken (normally due to historic probing that hasn't been covered/repaired allowing moisture in) the remaining 2% will still pass a "buzz" or "continuity" test yet an analogue voltage or resistance signal signal will (generally speaking) fail due to a backfeed or bottleneck.

 

[MicKPM]

Cup looms have a few common places they become damaged due to Renaults poor cable management used on this specific model. They also have other issues that contribute towards throttle pedal related issues but first rule of business... never tell everyone EVERYTHING that you know

Liam, cutting and shutting wiring looms may fix your problem but I honestly believe your problem will be a poor connection somewhere between the cabin and the ECU loom section. Without testing and basically getting balls deep in it I cannot advise a line to pursue that won't result in wasting your time. You will 100% have to do some form of investigation work in to the looms and the engine bay connectors though.

Mick

 

[LiamR172]

As i know f**k all about wiring, do you think i'd be safe enough putting it into renault? Theres no specialists close to me so they are the best i have really!

Ill have a look today at the pedal wiring and try and follow the wiring and check all plugs etc and make sure everything is secure.

It first went into limp mode when i pulled off a roundabout in 2nd and went to overtake up an overtaking lane, as soon as i planted my foot it went into limp mode.
This was after driving for a good 35/40 minutes.

Thanks for all the help!

 

[MicKPM]

Do not go anywhere near a dealer.

 

[LiamR172]

Would an auto electrician be better then?

 

[MicKPM]

Yes but there's checking for obvious damage first which you can do yourself.

Pull the connectors apart and look for any signs of corrosion (light blue/green oxidisation).

 

[.GAZ.]

Do not go anywhere near a dealer.

FPMSL!!

 

[MG cup]

Yeah Mick I was meaning resistance test really but it was late. I'm just not sure there would be a clean path from pedal to ecu without resistors or some potential stoppage.

Liam, few simple checks to try In areas I have noticed are dodgy (French) points on these cars on the few cups I have had apart wiring wise.

Change the pedal for a start if you have one or at least put a spray of electrical cleaner or wd 40 into the plug as that's easy.

Cabin to engine loom connector, its under the scuttle panel on the passenger side, off with the wipers off with the scuttle panel and follow the wires from the engine fuse box to the car. You will come to a big square connector going into the car, unscrew the 10mm bolt, pull of the plug and check for any white/green corrosion or damaged pins (unlikely) , also a little clean or spray with wd 40 again.

Next one is the wiring loom as it leaves out the fuse box to the engine, take out the battery and removing any conduate or cable ties and check it hasn't been rubbing on the lower part of the fuse box underneath the loom.
​
Under the battery the loom also T's off in a few directions and the wiring is shocking in there, sometimes coiled up inside the conduate. Basically follow the wiring from throttle body to the fuse box while checking everything on the way and if any wires have went brittle/plastic like then take a note until hopefully you find a damaged wire of some kind.

Hopefully its just your pedal but the code does point towards wiring.

That should only take you an hour or two, it sounds difficult but all you have to do is use your 'enes'

 

[LiamR172]

Just tried Mikes peddle, it still does it so Mick is correct about not being the peddle. At least thats ruled out!

The connection to the ECU seems ok, no corrosion there. No corrosion on the plug on the pedle, or throttle body.

Ill try checking under the scuttle panel etc next.

What a f**king pain!!

 

[MicKPM]

Welcome to my daily misery

 

[LiamR172]

I honestly dont know how someone can do this sort of thing day in day out!

Is this a normal setup? It looks like a big mess to me, its all hanging together and stuffed into the fusebox.

 

[MicKPM]

Looks about right dor a ph2 172 yes. I'm not talking to you anymore though as mine gabe me the squiggle box and reduced power this afternoon.

You're bloody infectious!

 

[LiamR172]

Your joking?

Let me know the cause of it when you fix it! Haha.

 

[LiamR172]

Fuses are pretty bad! Given them a clean now, just going to stick it all back together and see how it is.

Got a new air filter today aswell, last one was disgusting so i dont think that was helping

 

[LiamR172]

Cleaned all fuses and everything else, and its still doing it.

Checked all the wiring that i could see coming from the fusebox and ECU, retaped it and covered it all back up.

Going to put it into an auto sparky and see what he can come up with!

 

[MicKPM]

Come fix mine then please - its now "limp home" fucked!