Weird!! went to car today, 1st time since yesterday, and car no flashing arrow and all gears available??

I know when i once accidently didnt replace plug lead properly, it brought up engine management light, but after about 25 cycles, the system 'clever' enough to put out light, as there was no longer a problem, but why light on yesterday and out today..........???????

Also, car started fine, but ran rough very briefly!! This could be bad plug though (ive never been happy with 'new' plugs i put in a few months back) AND, ECC was on (quite low, about 18 degrees C) and outside temp 2 degrees C, and the (new!!) compressor didnt kick in. It did though with system on manual control, so i suppose this correct, cas also on ECC it seemed ok with higher temp set. It's just i was wondering - can bad PNP mimic 'kick-down', ie, when on kickdown, AC is turned off temporarily.......................

Thanks,

Kevin

NOTE: problems in the past year: evaporator failure, check strap replacement including welding needed, rear main oil seal failure, heated seat failure, AC compressor failiure.........................luckily I can/have fixed al of these myself!!!