Hi: On my previous Jaguar 02 X-type, the CEL would go out after five successive turnons if the cause of the code was removed. I cannot find any information as to what conditions if any must be met to remove CEL on my X350 04 xj8. Some unknown condition caused "restricted performance" yellow warning plus CEL last week but then warning would go out usually when roadspeed or RPMs were lower than freeway speed. At no time did car feel any different than completely normal. Autozone free reader stated no codes were stored after restriction light went out but CEL was still on. Is there a secret sequence to extinguish CEL after fault condition rectifies? Or do I need to go to dlr for $129/hr analysis? Thank you. --Tom H

 

I'd suspect that the fault is still there but the Autozone reader didn't find it. Not surprising.

 

Just the other day I had the CEL come on. After a couple of starts or time it went out. Probally because the fault was a one time trigger. I received my code reader after the CEL went out on its own. Read the codes, lean left bank code was stored, but no longer exsisted. I am not fooled, it will be back, just dont know when. Can you tell I'm from old world LUCAS? But then again the car was idling for about an hour while waiting for a really late train. Many codes will clear themselves, if the engine cycles enough times and the fault no longer exsists. Time will tell.

 

MIL will go off if fault cause no longer present for 3 warm ups, but codes remain stored. It's mandated by law (of US and other countries).