Hi Warren,

Thanks for the message. No that isn't water damage (its all in a sealed box...). I suspect from memory it is just a bit of silicon sealant gunge / thermal paste from when I pulled it apart. Note that when Volvo 'clean' the TCM they do not pull it apart like that but merely spray the bejesus out of it or soak it in a bath of cleaner in the hope they get the gunk out. I suspect if you have access to an ultrasonic cleaner you may well get a pretty decent result by soaking it in an deep bath of cleaner. Volvo also give the venturi area and throttle plate a good clean.

Alastair