Automatic gearbox woes!

[f11nty]

Wondering if anyone can shed any light on this subject?...  I have the auto gearbox with a 2.3 petrol engine.  All was fine until the oil cooler began leaking oil in to the water, since then all sorts of problems have occurred, I have changed the cooler, the oil, cleaned the filter. I reset the ecu  which was showing a G38 fault code( speed sensor) new fitted. all worked perfectly for 10 minutes and thought I has solved all problems, and than all drive has been lost. If I switch off the car I can get a first gear and pull off but with in half a mile the car starts shuddering and I go no where.  The engine management then comes on saying Transmission control Failure

Was all fine until the loss of oil.  Question 1:   are these gearbox ecus transferable car to car?. 
                                                Q 2 the speed sensor fault keeps reoccuring even with the new sensor does that point to ecu trouble ,

I have checked and cleaned all terminals around the gearbox.     Any help would be appreciated.

Cheers  Wayne

[Mirez]

Hi Wayne and welcome! When you refilled the gearbox oil did you do it with the engine running or not?

[f11nty]

HI, thanks for the reply,   I refilled the oil to the level , then run the car and selected a few gears. re checked the level and topped it up, I done this until I managed to get 3.5 litrs  of oil in the car,

Today I have lost reverse gear, I can select all gears it just has no drive in reverse but I have forward gears as normal apart from the car is in limp mode again and stuck in 3rd, if I shift into 1   2  then 3 I have these gears but no 4th..

It just all seems a bit random and im beginning to suspect the ecu???

[Chrispb]

Have you looked at engine/transmission wiring loom for damage/corrosion.