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Bad ECU? How do I check my brainbox...

2479 Views 18 Replies 10 Participants Last post by  Gypsy_Botanist
I was driving the other day and shortly after I got fuel, my tac, speedometer and all of my gauges went dead. I thought/hoped it might be a loose fuse & continued to drive her for about an hour and then I started to loose a little power, she just couldn't maintain 75, I was driving on the highway, and slowed to about 60 with the same amount of throttle on level ground. Then all of a sudden she starts kind of chugging or gives a shudder, a few seconds later she backfires and I lost all power. She died when i took her out of gear, or maybe I turned the key off. After I got her stopped I tried to start her up, and got nothing. The fuel pump turns on and the engine cranks and turns over but no fire (I've not checked the plugs for fire yet so only 90%). I also have no check engine light, not even when you turn the key or for the few seconds it turns on after starting. I tried turning the key thrice to see if she is throwing any codes but I got nothing. So i think the brainbox is dead I just don't know how to test it. I thought I could plug an OBD computer into it but I don't know where to plug it in at, or any other ways to diagnosis it. I'm going to get a relay checker and check all the relays and fuses under the hood. If anyone has any other ideas about whats wrong or how to check your brain box please let me know.

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Mine does this occasionally. There's a fuse under the dash that controls the gauges (and other things). Those fuses get corroded and with the vibration of a running Jeep, they'll stop letting electrons flow.

Pull all your fuses out and clean off the corrosion. Or just replace them.
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