I have a 1998 Caravelle auto petrol 180,000km in which I am 100% dependent upon and it has some puzzling problems following gearbox servicing and I’m hoping you might be able to point me in the right direction. As what seems the norm of VW servicing agents they didn’t do a proper AT fluid change and I ended up doing the gearbox, got that fixed by a specialist Auto transmission place over here in Byron Bay region, whilst not specializing in VW’s they have done a lot of them.


Had one of the knock sensors replaced following gearbox rebuild (other had loose wire but not showing any codes) and me old girl started purring sweetly taking a local steep hill fully loaded at 75km and climbing in speed with no hesitation in gear changing………………….


500kms later it is a different story, same hill will change gears 3-4 times in immediate succession and can barely make 40-60km/hr up the same hill. Gears changing jaggedly and running 3000 - 4000 revs before changing gears.


Local VW repair and restoration specialist ran all sorts of tests for me, no codes on test, compression, ignition etc and found no problems. On advice from AT place they tried changing ECU, couldn't find the requested transmission ECU to test with so tried changing the main ECU but hit a "immobilization" issue and went no further as they have no idea how to find or get past this code issue. They have basically washed their hands, shrugged their shoulders and said no idea. Automatic repair agent retested with computer and re-checked AT again no problems found, told me this vehicle is known for problems and to upgrade, which I don’t have the funds for.


Any help or advice in what to test or try would be much appreciated as this old girl is my home as well as my transport and I have limited funds to fix and insufficient to replace.

Specific questions I have:
has anyone changed the transmission ECU? Does this also have a immobilization issue when changing? Does anyone know where I can source one new or second hand? If second hand what do I need to look for so I don't buy another problem?

In regards to the main ECU, how would I find the code or get around the immobilization issue? What should this job cost and how likely is it to be the issue?

Could it be the knock senors being faulty but not showing a code? Should I try replacing them again?

Does this vehicle have a limp mode if carrying too much weight? My vehicle is pretty loaded down with being my home, what is the maximum cargo this vehicle can carry?