Automatic Box Renault Megane Classic

I have problems with the box. Constantly move to about 100-120km/h jumps fourth in the third and lights the cash failure witness. It is a 1998 Renault Megane Classic.

First, turn on the computer and see what error code it gives you, then proceed.

I'm having the same problem, have you managed to fix it? How?

I have the same problem with a 2.0 automatic Megane Expression... I can drive around town without any issues, but when I accelerate to around 100-110 km/h, it downshifts to 3rd gear and there's a noticeable engine braking effect... I hope someone can help... or if you managed to fix it, could you share how you solved it?

Thanks!!! And good luck!!!

I had the same problem, and the solution was very easy. It took them quite a while to figure it out, but I was lucky enough to find a mechanic who took the time to look for the fault and found it. Let me tell you, the first thought was to replace the whole gearbox, but after several tests, they found the solution. All of this took me several
months, but that's the least of it.

First, they changed the spark plugs, and... nothing (they thought it might be an
electrical issue).
Then the ignition coils, and... still nothing.
In the end, they changed the solenoid valve that regulates the transmission lubrication, or
something like that. They also changed the transmission fluid.

From what you're saying, the problem was exactly the same. I think you can rest easy. Above all, don't let them touch anything without knowing what's wrong. They connect the computer, and with the car running, it generates a graph of all the parameters.
If you'd like me to call you, send me a number; I'm very interested in helping you.

My car repair invoice says:
LABOR
OS Check gearbox fault
Vehicle test
Online pressure check
OA EXT-REP HYDRAULIC DISTRIBUTOR

MATERIALS
VALVE COVER
GASKET
3.5 L RENAULTMATIC D3 OIL

Total invoice including VAT: €300

Have faith, I was desperate, especially considering it was a new car.