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Looking for help: Keyless entry

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Old May 8, 2022 | 08:10 PM
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Default Looking for help: Keyless entry

Hey all, wondering if I could get a little help here. My ‘97 SC400 with its factory keyless entry beeps when I lock and unlock the doors with the FOB. However, the lights don’t flash, like most new cars do. I have read that in 1998 they updated the keyless entry system to make the lights flash.

Does anyone happen to know how I can make my ‘97’s lights flash when I lock and unlock? Perhaps I could update to a newer computer from a ‘98? Or, just wire in something to my existing setup?

Before anyone suggests it, I don’t want an aftermarket alarm. I like all factory stuff and don’t want to have stuff cut up and added in if I can avoid it. Thanks everyone!

Nick
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Old May 9, 2022 | 12:54 PM
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A good question here. FWIW, keyless entry on 98+ SC models will flash the running lights only and not the turn signals/hazards like all other models.
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Old May 9, 2022 | 02:57 PM
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This is a good question. A LONG while back I looked into how to rewire my 1993 model to make the lights flash and give an audible beep. I found a company called KP Technologies that offers such a module to do this... and I still have this module brand new in the packaging... but I never got around to wiring it up.

Your OEM+ approach sounds more appealing though. I think you will need to download the full wiring diagrams for your 1997 SC400 and a 1998 SC300/400 (and possibly 99-00) in order to compare how Toyota set up such a minor difference one model year later.

Personally I've now become interested in the feasibility of swapping in either a 1995-1996 or 1997-2000 door lock ECU hardware that is different from earlier models so as to add newer key compatibility AND the factory beep and light flash functions but I have yet to look into it to see if that's entirely too difficult to achieve or not.
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Old May 9, 2022 | 05:11 PM
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Hello,

The lights flashing is controlled by the Keyless Entry ECU, the problem is that between 1997 and 1998 model year, those are drastically different, both in terms of wiring, as well as location and mounting. I don't have a wiring diagram for a 1998 SC300 unfortunately, but I did find pictures of both ECUs on eBay, those are below. While it is possible to make it work, it will require even more messing with the wiring than an aftermarket unit, or the whole wiring harness replaced.



While not the prettiest, aftermarket modules are pretty easy to install, and some are even customizable. Other than that, depending on the setup, it may be possible to go about it with no wires cut, making a setup completely reversible, here is an example of me modifying the way fog lights in my 2000 ES300 for them to turn on with corner lights, I haven't cut a single wire to make it happen.

Hope this helps and best of luck!
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Old May 9, 2022 | 07:34 PM
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Originally Posted by ThomasGS4
A good question here. FWIW, keyless entry on 98+ SC models will flash the running lights only and not the turn signals/hazards like all other models.
what does FWIW stand for?. Also my 99 flashes the front driving lights, bumper sidemarkers and rear hazards.
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Old May 10, 2022 | 04:33 AM
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Originally Posted by - V -
what does FWIW stand for?. Also my 99 flashes the front driving lights, bumper sidemarkers and rear hazards.
For what it’s worth

Thanks all for the input. Especially the picture of the two different plugs. I was hoping it would be easy but this looks tricky. Perhaps it’s best to look at after
market like you said. Long term I want to do a system from Advanced Keys to act like a new car, it will automatically unlock the door when you approach and has push button start. Maybe I’ll just wait did that. It’s a $550 product so it’s not a priority right now.

Nick
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