Fault code problem on a Cavalier????????

Hi group

The car is a 1993 L-reg Vauxhall cavalier it is the 8 valved 1.8 litre
engine.
The engine management light stayed on today and the revs dropped down to
500.
I got back and did the paper clip test on the diagnostic plug.
After it flashed the standard 12 three times it revealed the fault code 24
this was the only fault it had.
Because after this it flashed the standard 12 3 times again.

Can anyone tell me what code 24 means and what I need to do to resolve the
fault.
Any help or advice would be gratefully appreciated.

 

I have now found out that code 24 means a fault with the speed sensor (MPH)
My Cavalier has a speedo cable so why is it telling me there is a problem
with a speed sensor.
Any help or advice you be greatly appreciated.

 

Some (not very useful) information here

http://www.cavweb-forums.co.uk/showthread.php?t=7068

But try posting to cavweb, fantastic resource for Vauxhalls.

 

Some late Cavaliers / Astras had a sensor on the back of the speedo that
lets the engine ecu know the vehicle speed so even though you have a cable
you also have a sensor.
Check your fuses and see if light comes on again.