Intermittent engine starting problem

[Jocheung]

I've just purchased a 2004 Renault Megane 1.5 DCi 80. It has 118K miles on clock, part service history and 8 previous owners.

After a few days of owning car I had problems starting the engine. Symptoms as follows;

1. Unlock doors via remote fob.
2. Open door and dash board does not light up. Normally lights up with 'PLEASE INSERT CARD' but this message is not there when there's a problem.
3. I then insert key card into slot.
4. Press 'START' button and no response, no dash lights, just silence

After several attempts of locking/unlocking door and spraying WD40 onto electrics in bonnet the 'PLEASE INSERT CARD' message displays and the engine starts as normal. It will start as normal throughout the day. So far the problem has only occurred in the mornings

The left wheel arch bulb access cover and a bulb cover were missing but I managed to source these from eBay.

I really like this car and would like to get this problem fixed. This maybe difficult which would explain why there are so many owners for this car.

Does anyone have any suggestions please?

[460316DSG1]

Hi. It has to be Damp or Dry Joints on connectors if it works after spaying with WD40.

Take connectors apart and spay inside, it will be trial and error, one of them is not making a good connection.

Switches as well give them a spay.

get some Damp Start and spay all the Cables you can get at.

Hope that helps.

460316DSG1

[tomalamix]

the cover were missing...what about water inside, did you check it?

[Jocheung]

The weather seems dry tomorrow so will try disconnecting some plugs and spray some cleaning oil on the contacts. I have nothing to lose. There was no water to be seen in the fuse box compartment. I had driven in the rain a few times without any problems. Its just starting it up in the mornings that's the problem. Once it starts up its fine for the rest of the day.

[AlexB]

Perhaps, due to the hatch cover missing earlier and water damage, the UPC refuses to power up the other ECUs intermittently...

[Jocheung]

I gave the electrics a good spray behind the battery and around the fuse box compartment. Tried to start up car but still had the same symptoms. Did a few random things in the car and the dash lights lit up when I closed the glove box. Looked at the fuses in the glove box and located one for the dash. The fault symptoms I get are exactly the same as when the dash board fuse is taken out. Next time this happens I will fiddle with this fuse. Hopefully that is the cause.

[Jocheung]

I think the problem has been fixed.

After experiencing the problem a few times I finally traced the fault area to either the UCH board or the wiring loom surrounding it (area above glove compartment). The wiring seemed fine and the only thing I could think of was to replace the UCH board. I've heard these things could cost around £600 from Renault to be fixed so I was looking for a cheaper solution. I managed to find a seller from a popular auction website who could supply a used UCH for £85. This price including reprogramming the used one with the same details from the old one. I had to post my one to seller for it to be cloned. After 2 days of sending off I received both units. The new UCH has been fitted and used for 4 days and so far I have not experienced any of the old problems.

[460316DSG1]

How easily was it to get the UCH Board out/in.

460316DSG1

[Jocheung]

It was fairly easy.

Remove the door frame plastic cover near door hinge.
Remove the side dash cover.
Use T20 screwdriver to remove 5 screws which secures the glove compartment.
Remove glove compartment by pulling it out.
UCH is located just above glove compartment and secured by a bolt. Unscrew this then unplug the plugs and thats it.

Takes me about 5 minutes.

Update: Since replacing the UCH I've had no problems so I'm convinced its now fixed.

[freelanderuk]

Thanks for the update

[460316DSG1]

Thanks for the information.

460316DSG1