Fault Code Question

[Miles]

If I bridge a & b on the diagnostic plug with just the ignition on I get 3 12's and 3 31's. If I do it with the engine running I just get 12's.

12 is no rpm (crank sensor) signal.

Does that mean it has stored that code but isn't having that problem at the moment?

Surely no crank sensor signal would have a major effect on the cars running!

I disconnected the ecu for about half an hour and I still get 31.

The car runs fine, although isn't holding more than 0.95 bar.....

[Tom Williams]

12 is the initiation of diagnostics, 31 is no crank sensor and cos the eingine not running it flashes up

[Miles]

Cheers Tom, no problems there then