Speedometer and odometer priem

[Skones]

Hi. I have a 2002 Yaris purchased and used in the Uk. For 6 months the speedometer has worked intermittently until the last month when it has stopped working completely. It has a digital instrumentation panel and the reading appears but is consistently zero. The Odometer is also not registering the miles travelled and is stuck on the last number it reached before the speedometer stopped. I have checked the connectors at the back of the panel and the are all fitted securely. A garage tells me that I am looking at £210 ish ($250) which is not really worth it given the age of the car. However. I am not sure they know what the problem is. My guess is that it is the speed sensor. I am a novice car maintainer. Where is the sensor located on a 2002 Yaris. I read it might be in the gear box in which case it is too much to tackle but I also read that it may also be situated reasonably accessibly on the transmission and removable quick easily. Has anyone got any advice on if and how I should tackle this problem?