Hey everyone, when I got my evo last year I'm pretty sure the Check Engine Light use to work. I was on stock 9417 software. Since than I've turned off a lot of CEL codes, like rear O2, and EGR and what not and I updated everything to Tephra V7. But now my CEL will not turn ON at all. Checked the bulb and its fine, I even switched it with one of the other bulbs that works for sure so its not the bulb.

Shouldn't the CEL come ON when you first turn the ignition to ON position like most of the lights? And than turn OFF once you start the car? Mine does not

Could Tephra v7 software update have anything to do with this issue? Can't find anything similar anywhere.

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Yes it should come on when you turn on ignition

 

Than what could be my issue, bulb is fine yet it doesn't come ON ever...


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How are you sure it isn't burnt out if it never comes on? When you turn the car on and the cel light doesn't pop up then it's most likely burnt out. If you really think it's tune related just load a stock rom onto the car for a minute. You wont even need to crank the motor, just set it to on.

What i mean by burnt out is the actual connection in the instrument cluster, not the bulb itself.

 

I had the gauge out already, and tried switching out the bulb with a different one that works for sure, like my seat belt of turn signal bulb. And 2 connections for the check engine bulb don't seem to be damaged nor burned out.

And that isn't a bad idea! I'll try to find stock Evo 8 rom and try it just for a sec


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If you cant find one just PM me, I will send you a stock rom.

 

With old bulbs just the act of handling them can cause them to fail.