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Will a burnt bulb throw a CEL?

theblet

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Just got a check engine light. Hooked up the code reader and it says N/A. Truck runs fine too. The only thing I noticed is that there is a burnt bed light (by the third brake light). Would this cause a CEL? Thanks
 

Rlaf75

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Is it actually the Check Engine Light? A blown bulb should illuminate a light on the dash that looks like a horseshoe and or an actual message on the display indicating a bulb failure.
 

theblet

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I believe so. It looks like this. But no code just N/A

BB4053EC-4870-463F-A248-97CDE71CC0DF.jpeg
 

theblet

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thats definitely the check engine light but I wouldn’t have thought a burnt out light would cause it .
I wouldn’t either. Just thought I’d ask since newer vehicles do things out of the ordinary. Guess I can replace the bulb to see what happens. Thanks
 

Rlaf75

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I wouldn’t either. Just thought I’d ask since newer vehicles do things out of the ordinary. Guess I can replace the bulb to see what happens. Thanks
A warning light yes but no engine light. Unless of course it's some new "feature".

What scan tool did you use and have you used it on this truck before? Some older cheap code readers may not be compatible with CAN-BUS systems
 

theblet

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A warning light yes but no engine light. Unless of course it's some new "feature".

What scan tool did you use and have you used it on this truck before? Some older cheap code readers may not be compatible with CAN-BUS systems
It is a cheaper code reader, which I’ve used before on my truck to read an evap small leak code a few weeks ago. Here is the one I have.
F53830BE-AA91-4C52-85CD-DE07FA7E1A8F.jpeg
 

Rlaf75

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That code reader may not read the code if it's a manufacturer code specific to that vehicle. For shiznits and giggles go to your local auto parts store and have them scan it. They usually do it for free. If they can read it, write down the entire code and have them clear it
 

theblet

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Well, I started the truck this morning and the CEL is off. Also the bulb is back on! 🤷🏻‍♂️
 

theblet

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To test the theory, guess I’d have to remove the bulb and see if the CEL comes back.
 

theblet

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Well, the bulb went out again, but no CEL. I tapped on the third brake light and the bulb started working again.

when I plug my tester in now, it still says there is an active fault N/A 01/01z no pending faults.
Not sure why there is no CEL if I have an active fault.
Any ideas?
Thanks
 

Rlaf75

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Well, the bulb went out again, but no CEL. I tapped on the third brake light and the bulb started working again.

when I plug my tester in now, it still says there is an active fault N/A 01/01z no pending faults.
Not sure why there is no CEL if I have an active fault.
Any ideas?
Thanks
Did you put LED bulbs in? They have been known to cause issues
 

Rlaf75

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No sir. All stock bulbs.
I would start by replacing the bulbs. While you have the light assembly out check the harness connector for any corrosion. Clean it as needed and apply a little dielectric grease to the terminals and plug it in and if it happens again
 

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