Codes

HELP, All of the aticles I read on reading codes asY "THE CHECK ENGINE LAMP WILL BLINK". My 90 XJ dosnt have a check engine lamp, is it possible that it could another lamp thats supposed to light up? OK before you all start laughing I have tried doing the "key trick" and nothing lights up at all, I've changed/checked all the bulbs and thay are working.
Thanks in advance.

Sorry, the Renix injection system on a '90 does not store any codes. The key thing only works after '91.