250 Help please. Speed sensor issue?

Hi all

Any ideas you have on this would be appreciated. I have searched and come across similar issues but not quite the same issue.

Last weekend i was cruising home along the dual carriage way in horrible weather, when the following happened:

• Stop and Serv lights on
• ABS light on and Brake System Fault message (brake fluid level is OK)
• Speedo fell to zero

I checked the brakes were still working (assuming ABS is probably not) and pulled over. When i came to a stop i applied the hand brake. Car then starts beeping me to tell me the hand brake is on (like it does if you apply the hand brake when moving). I then go to turn off the ignition and i can't, pressing the on/off button does nothing. After about 10 presses it switches off. When i then open the door, the car starts beeping at me the Door Open message (again, like it does if you are moving).

At this point i assume the car cannot tell if i am moving or not, hence the speedo not working and the various alert messages when moving and when not moving. So i restart the ignition and carefully drive the car home. On the rest of the drive it is also apparent the power steering is either not working or is not increasing its assistance at lower speeds, as the steering is hard work at maneuvering and low speeds. Get home, press on/off button about 10 times again to switch it off again.

To me all the signs point towards the car not knowing how quickly it is moving:

• Speedo not working as cannot tell speed
• ABS/Brakes System fault as cannot tell speed
• Power steering cannot adjust as cannot tell speed
• Wont turn off ignition as cannot tell it is not moving
• Beeps door open and parking brake on as cannot tell it is not moving

Would an ABS sensor failing cause all of this, i've seen other threads for failed sensors and not seen the speedo not working listed?
Weather was very bad, water got in somewhere?
Any other ideas what this might be?
Do i need to get it plugged into CLIP?
Any ideas are welcome.

Thanks!