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Electrical fault requiring diagnosis!

V6veteran

New Member
Symptoms: car was running perfectly. Then left it for about three weeks covered but in wet and cold conditions. On reconnecting a fully charged battery the engine started but was clearly not running smoothly or with normal power and the accelerator pedal had no effect whatsoevr on the revs! The dash display showed the electrical fault icon illuminated. Does any 'bright spark' have a diagnosis - and better still a cure - for this problem? Happy New Year to all in the club.
 
Happy New Year!

Do you really mean "absolutely no effect on revs"...or was it a delayed/slow increase in revs?
If it's sounding rough, that usually points to defective ignition coils, a very common issue, but if I remember correctly that brings on the engine warning light, not electrical fault light.

Presumably battery is confirmed fully charged and both + and - are tight on the studs?
 
Thanks Ben,

Yes, had coil problems myself and it was I think the engine warning light. No, this was very weird because the engine seemed to tick over around 10 mark but showed no, or extremely minimal, response to any degree of accelerator pedal movement. Battery definitely OK, fully charged and the starter motor, at least, was very lively!! Looks like engine diagnostics, here we come! I'll post the answer when I have it, unless anyone else has any thoughts
 
It’s a curious one. Will be interesting to hear what diagnostics brings up.

Dodgy ground(s) maybe?
 
Hi there. You might have solved this by now but i would say it sounds like s fault with the fly by wire throttle system. Possibly the potentiometer at the front that sits on a bracket next to the ABS unit that is operated by the short throttle cable or possible the electronic throttle body. I would say that if the car was subjected to damp/ moisture for a while this could have caused a problem with the under bonnet potentiometer. This is probably a Laguna V6 item which may be situated inside on the Laguna away from damp/moisture etc. It might just need a clean / dry out or perhaps a new one but as i said could also be the throttle body or a wiring issue. Definitely get a fault diagnosis done on it first though before you touch anything.
 
Get someone with a decent scanner like a Solus or Modus and read the live data, on a ph2 you can read the throttle percent demand and percent delivered directly, basically you will watch the pot move on a screen graph. i do have such a scanner and have done this on the clio, any late model Snap-on scanner will directly read this, do not confuse these scanners with the £99 stuff from ebay, they will not show live data only codes, if the throttle pot or throttle body pot is intermittent this may not throw a code as it usually resets to zero. of course if the light is on and stays on there will be a code but it may not be obvious, remember this technology is 20+ years old. cutting edge on the day but not now.
Another fault it could be is the fuel pump failing or reduced pressure, the car does not register the fuel pressure at all but assumes its ok. if the pressure is low this could lead to poor fuel spray giving a misfire and then a rich reading at the lambda, this could be due to the car sitting for a while.
Ask the forum about fuel pumps, mine sat for three weeks and the pump just locked solid, they also suffer with the pressure relief being stuck open, same symptoms.
Bad news is i am in Nottingham. and sorry for the gloomy outlook.
good news, if its the pump i can rebuild it.
 
Hi There, Had a similar problem about a year ago, this may not be related but An option to keep in mind, I was driving home normally when my car completely cut out. eventually got it started but wouldn’t rev (went into limp home mode). I noticed when it was running that both cooling fans were constantly on no matter what temp the engine was at . checked the fault codes and quite a few were displayed , codes included drive by wire System (pedal and throttle body), I eventually traced the problem to the air con pressure switch. ( I know this sound ridiculous !) Turns out this sensor is Part of the regulated voltage circuit controlled by the engine management system. The sensor was badly corroded and was shorting out . This was causing havoc with the engine management system , it’s easy to test this by disconnect the plug and clearing any fault codes . My Car drove perfectly After this. Changed the sensor and no problems since. Sensor is located it the passenger side of the A/C rad (At the bottom) , the plug can be reached via the passenger front wheel arch.
 
Hi again
I am posting a reply to myself as I now have an update on the electrical fault that stopped my accelerator communicating with the engine, Clever diagnostics has now shown that the problem is a faulty THROTTLE POSITION SENSOR - A bit like Airbus really: the V6 'flies by wire' . So, does anyone have for sale, or know how I can get, this part (phase 2 clio) ?
I have always found this forum very helpful and it is always nice to come up with a topic that has everyone guessing - but then I do seem to go in for these rather obscure failures in these wonderful machines !!! Mine is getting old now at over 31000 miles.
V6veteran
 
Does anyone know the part spec for above throttle sensor please and/or have a pic of it or relevant bit of the service manual (ph2) ?- I seem a bit stuck on getting this through the usual suppliers at present. Congrats JulesV6: your diagnosis was spot on - maybe you can point me towards the cure as well. Thanks to all for your help.
Happy motoring (while we still can!)
Nick
 
Looks like its a 6020014210

I would have expected it to be the same as a 172/182 part so might be worth checking up on that.

Also before buying make sure it's not wiring or wiring plug related.
 
Hi Dave and anyone who can help: UPDATE - I am actually looking at the other end of the link - not the accelerator pedal, part number kindly provided by Dave, but the throttle position sensor ia what I need. I now know it is made by Bosch, part number: 0280 750 154 but can't find any of these anywhere on line. So I am well and truly stuck: any suggestions as to how I can get this elusive part would be most welcome.
Thanks
Nick
 
If you're looking at the other end, then I think you're looking at a complete throttle body, I don't think you can get just the sensor separately.

That's a specific V6 part, hence why nowhere has anything in stock.


You're maybe best trying SG Motorsport. See if Scott can help.
 
Hi Scott,
I wonder if you have any suggestions. Ben said best to contact you. a) do you have access to the throttle body? or b) are there any substitutes that will do the job?
Thanks in advance and thanks to Ben for the reply - never give up!
Nick

[mention=62,#000000]scotty6r4[/mention]
 
If it’s the complete throttle body your looking for the part code is :
GENUINE RENAULT CLIO THROTTLE HOUSING (7711120019).
I would double check this is the fault before shelling out circa £500 , these throttle bodies are quite robust. I would get someone to disconnect and check Resistances with a multi meter. The unit can also be opened to check the condition of the internal wipers and tracks.
As I mentioned previous my car threw a similar fault code, and turned out to be something completely different.
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Hi v6veteran. I'm glad my diagnosis was of help, seemed the most common sense thing. My racing experience working with Renault sport engines has shown me that the fly by throttle systems do give trouble especially when used in unusual enviroments. Have you sorted the problem out yet ? Was it potentiometer or throttle body ? I could be wrong but i'm sure Renault would have used the matching potentiometer from a Laguna V6 to fit to the Clio V6 as the engines & management system are effectively the same. Although yours is a phase 2 so could be different in some way.
 
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