be careful when dealing with old screenwash has been found that this is a breeding ground for legionnaires disease (make sure you top it up with a good additive as just water not good)
when i brought my 1999 2.3 auto it had a abs sensor fault . this did not effect gearbox for me no limp mode so dont think thats your problem beleive you have more than 1 sensor on your gear box will see what your fault code throws up when i get home