check injection UPC problem.....

[daleslade]

Hi, I recently purchased a 2005 renault megane 1.9DCI. after a couple of weeks, i got an error message check injection with the service light on everytime i started the car. i took it ot renault and they diagnosed the problem as being a short with the UPC and i would have to replace the computer. if i start the car, stop it and start it agin, the error message and the service light go off. i asked if it could be the EGR valve or the glow plugs and was told they are fine according to the diagnostics and it was definitely a short with the UPC which needs to be replaced. i was wondering if anyone else has had a smiliar problem and how they rectified it, and also if it is a serious problem if i carry on driving as it is an expensive excersise to replace the UPC. Cheers

[nickbell69]

Lot of people get this message and most of time it is glow plugs.
Would be worth spending £30 on new set before paying dealer a fortune to work on car!!

[daleslade]

I also have a suspicion it is the glow plugs but will that not show up on the diagnosis of engine and injection system, the fault error code was defintately a short from the UPC? will check glow plugs next weekend and see how they look. Really weird that if i start the car, stop it and then start again it goes away, damn technology!

[monkeymanonk]

Did you sort the problem as i have the same fault?
Any help please!!!

[AlexB]

What codes did they read from the on-board computer?

[Poddy]

I have a similar problem

when im driving around 30mph in 4th gear by car starts chugging, but when i let my foot off the accelerater it stops,
ive took the car to the dealerhip they keep telling me theres nothing wring with the car, anyone else had this?

[daleslade]

I Haven't had any performance issues with the car, i do however have an extended warranty on the car so i am going to claim on the UPC as the error code was definately a fault with the UPC (a short), so if covered I will replace and see if that alleviates the problem. will keep you guys posted.

[daleslade]

Hey, replaced the UPC and problem solved. No more check injection lights or service lights, good to see "no message available" again! Miles of smiles now hopefully.

[Andy Ramsay]

I had the same problem with my 1.9 dci 120 scenic II. Ireplaced the glow plugs and that cured the problem. The reason that the warning lights go out after the engine has been run for a short time is this:- The engine mamagement computer does not require the glow plugs to switch on and pre heat the cylinders as the engine is already warm and combustion will take place more easily, without the need for a preheat.

The injectors cost me £8 each from my local motor factor and they are relatively easy to fit. Care is needed when removing as they can be quite tight. Also care needs to be used when replacing to get them started on the right thread. Cross threading them can lead to a nightmare scenario as they may not seal properly and reach the required position. They need to be tightened to a required tightness so a torque wrench is handy.