C5 HDI auto gearbox - machika
I have just mentioned in another thread my current experience with the auto gearbox in our C5. Basically, I took the car to the local main dealer to sort out an engine management fault and I was persuaded to have an update to the engine's software to help trace the problem. I was initially told that the original software had a fault and that the update had sorted it out. This proved not to be the case but the problem was ulitimately sorted out.

What I didn't know, at the time, was that an update to the auto gearbox software was required at the same time as the engine software was updated. The result of this software update is the characteristics of the gearbox have been changed for the worse. I, and my wife, always thought this was one of the best auto boxes we had ever experienced but now it is not as smooth in its changes and the changes are also rather erratic. It seems to change down at higher speeds than it used to when, really, the torque of the engine should be able to manage without changing gear until a lower speed is reached. For example, negotiating islands and tight bends at speeds of between 30 and 40 mph used to be no problem for 3rd gear, but it will now change down to 2nd gear at about 35 mph. Also, I recently had a very odd occurence when travelling on the A50, when I was travelling at about 85 mph and pushed the throttle pedal down to accelerate past a line of cars. The gearbox kicked down to 3rd gear which, with all of the torque that the engine has, seems ridiculous. The gearbox was locked in 4th gear at the time, there was no extra load on the car, no incline and no reason to explain this behaviour, which also happened once, recently, when my wife was driving the car.

I have talked to the technician, who did the update, and he has told me that it is not possible to re-install the old software. How they sort this one out now, I don't know, but the car is going back to the dealer next week. It is very annoying to think that I have paid for something that has made the car less enjoyable to drive.
 

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