My wife used my car this morning and came back and said theres a warning light on the dash and the speedo's not working

So I've just taken my car for a spin.
After starting the power light flashes about 16 times.
Check engine stays on constantly.
Speedo no longer works.
Electric radiator fans constantly on.
Is this coincidence that they all happened at once or do you reckon they're related?
The engine sounds fine, car runs really well (goes like a shower of sh!t), water, oil and auto fluid all OK. Runs at normal temperature. Just don't know how fast I'm going now.