Key immobilizer antenna connection?

2004 HONDA PILOT
AUTOMATIC
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GRACHAEL51
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When I go to start my car. I know, I programmed an aftermarket key fob and come to find out. That was a bad idea that before it stopped starting completely, it had intermittent starting. So I've to my understanding, it has something to do with the car. Key mobilizer, antenna that is either broke inside or just too old inside of the steering wheel where the key goes in or when I program the aftermarket key fob, I somehow made my car think that I'm trying to steal it and will not allow me to start the car, what do I need to do should I completely replace the whole immobilizer system? As I've already checked almost every single. Fuse, except for whatever the information is underneath the steering wheel, the panel that you have to pull out, that has the soldiering on it to find out if it's sad or not. That's where I have stopped to find out to issue.
Aug 27, 2026 at 5:17 AM

What to check next

Diagnostic guidance. Suggested checks and possible repairs are separate from the owner's reported results.

Begin with the battery's state of charge, securely fitted terminals and cable voltage drop during the failed start. Tell the technician that the lights lose power during the attempt. A battery passing one shop test does not check every connection on the car. Do not repeat improvised battery-terminal or cable-shorting experiments. If power supply remains sound, check start authorization with the correct diagnostic tool and a known authorized key. If the battery repeatedly discharges while parked, investigate that separately after basic battery and charging checks. The power-loss symptom provides a useful first lead. Establishing a reliable electrical supply may resolve the problem or make a genuine immobilizer fault easier to identify.

Guidance references and applicability

Fluke: Diagnosing voltage drops https://www.fluke.com/en/learn/blog/automotive/electrical-automotive-troubleshooting Supports checking electrical feeds and grounds under load. Vehicle wiring, connector identification and acceptable measurements must come from the matching service information.

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STRAILER
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Hello,

We can help you get it going again. The first thing we need to know is while you are cranking the engine over does the security light flash? If not the immobilizer is not the problem, if so lets reset the system, this video we show you how.

https://www.youtube.com/watch?v=INiDRO5A5MY&t

Please let me know, a short video can help as well.

Aug 27, 2026 at 5:10 PM
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GRACHAEL51
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Holly crap, i pray this works. This is the one thing i javent tried oddly i did unhook the battery but i didnt know aboit this trick. This is what ive done. The first time it did blink, 3 times to be exact, after that it didn't anymore. Ive already check the main fuse box under passenger side hood and the fuse box on the left side of the drivers legs. I have not checked the one under the steering column or have i went as far to physically check the ring around the ignition key portion. I also tried resetting my main key by the switching of 0 I II ON, between the I and II with in between locking and unlocking the car door.

I pray this works. Ill be doing this tomorrow because its been at my work for 4 months trying to rack my brain and about to buy what i thought i needed. Ill let you know tomorrow evening. Thank you
Aug 27, 2026 at 8:35 PM
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STRAILER
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You are welcome! When the security system is enabled the light will link non stop while cranking. I have seen the RFI chip ring go bad or get damaged at the ignition switch as well FYI.
Aug 28, 2026 at 7:36 AM
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GRACHAEL51
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Thats interesting because when i was having intermittent starting the light wouldnt blink except the first time. I have to try again because didnt have copper wire, so it didnt work. Being on a quick limb i ended uo connecting my jumper cables but only red to the unhooked negative. That actually gave he something with the electric last night. Key was put in and being the door was opened i could see certain lights that are on always went off as soon as I went to go. Turn the key, so I'm gonna go back up. And hook a copper wire up from the hooked up battery positive to the unhooked negative and tried to drain all of the electricity that way. Afterwards, I'll take the battery up to autozone, to have it completely recharged and drop it back in and cross my fingers. Yes, I was assuming that it was the ring around the Ignition that broke because I did come across the fact. When they're this old, it happens every coverage rate savings, but I will say this. This is the first video I've ever seen anything like this before. So thank you either way, even if it doesn 't help me on this car. It helps me in the long run. Ill keep you posted thank you again
Aug 29, 2026 at 5:06 AM
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STRAILER
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No problem, also, if the battery is bad charging it will not help, you need to have it load tested to be sure the battery is good.
Aug 29, 2026 at 8:02 AM
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GRACHAEL51
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Well i will be trying to hook it up tomorrow. I drained it. So the time i knew it was all dead was when i went to start the car instead of not just starting everything went off. So i unhooked what i could as i didnt have everything needed. Went back up the next day and for kicks and giggles i tried starting it and it started right up. Unfortunately i dudnt have time to get it back to my place so i left it as its fine at work. Went to try it a couple days later and it was completely dead again. Had battery checked this morning and autozone said battery is perfect. Any clues, oddly im really hoping for the key immobilizer. Your opinion
Sep 8, 2026 at 3:29 PM
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STRAILER
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Yep, how do your battery cable terminals look? Please go over this guide.

https://2carpros.com/articles/everything-goes-dead-when-engine-is-cranked/

Also, when you are cranking the engine over is the security light flashing? If not the immobilizer is not the problem.



Sep 10, 2026 at 8:36 AM
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Discussion summary

Key immobilizer antenna connection?

The owner suspected an immobilizer problem after intermittent starting and extended parking. The account also described lights losing power during a start attempt and battery-connection experiments. A battery test reportedly passed, but the car did not remain reliably operational.

Reported outcome: An isolated successful start was reported, but no reliable repair was established.

The battery-test conditions and immobilizer data were not supplied. Security-light behavior alone was not accepted as proof that the immobilizer was healthy or faulty.

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