URGENT help need with security system problem

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Cathar_Knight

Cathar_Knight

10 Year 15 Year
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Aug 26, 2008
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((UPDATED INFO :: ECM? )) URGENT help needed with security system problem

Hello, and thanks in advance for the feedback and advice.
I have a 2001 LC 100 series.
About 5 years ago the second original key cracked and the black plastic part that contains the security transmitter came off. After a variety of semi-successful attempts to glue the key back together I discovered that you can have a regular metal key made and as long as the transmitter part is on the key ring all is good J
However – (you knew there was a however) – occasionally the car will not recognize that there is a key in the ignition at all and the red security light continues to flash even though my key is in the ignition. The last time it happened was about 2 years ago in Texas. It was a hot summer day and the car simply would not start (turns over but will not start). Eventually, after leaving the car for about an hour I just put the key in and it started right up.
I now live in CO, and yesterday it was quite warm (80F) and when I pulled in for gas I turned off my LC. When I went to start it up again – no dice! Same deal. Absolutely would not start. I found a local radio shack and replaced the batteries in both of my key transmitters and tried it about 30 mins latter. Still wouldn’t start. Finally I gave up and went to grab dinner at a nearby restaurant and debate my next move. I came back about an hour and half latter and bingo it worked. So I figured I am good.
Today it started fine in the morning and at lunch and after work, but when I went out this evening to run to the store it wouldn’t start again L It is 35F outside not 80F – there goes that theory. I left the vehicle for about 45 mins. Still wont start.
I know this is tied into the security system and I also know that I don’t want to spend $1000 to fix this problem. Does anyone have any ideas or suggestions?
Thanks,

Mark
 
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Any chance you have another key to try?

I ordered some replacement shells from Ebay. They are labeled Denso, but no telling if they're just knock offs. I had them cut at a local locksmith and stuck my original transmitter back in.

Also, I had some non-fob keys made at the same locksmith for around $70-80. These still start the car, but do not have key-less entry on them.
 
I have both the original transmitters. Both with new batteries. Both are seperated from the original key but this usually is not a problem. Neither key transmitter is recognized but both the FOB open and lock the doors just fine. I went out again after leaving the LC for about an hour and a half. Nope. Still not recognizing keys to start. Blah. :-(
 
The transponder chip is not powered by a battery. It is tiny - about 1/4" long. It's in a slot next to the remote (the part that is battery operated to lock/unlock the doors) and looks like this:

toyota-id4d68-transponder-chip.jpg


Make sure the transponder did not fall out of your remote shell. Also, it needs to be right by the key head, and it should NOT have other transponder keys near it when you are trying to start the truck.
 
Thanks, I cant see the piece you are referring to on either key. That could mean that they are both gone (would explain why it isnt starting) or that I am not looking in the correct place.

Is it attached to the FOB?

If it is gone - what next? Can this system be bypassed? Is there a way of ordering a new key?

Mark
 
You need to take the key apart (small screw). It's mounted on the backside of the button part next to the battery. I have a totally useless keyfob that was washed a few years ago with no battery and the truck still starts fine. The transponder can't fall out.
 
Yup, that's the remote. The Transponder chip is glued to the inside of the remote "shell". Pics to come....
 
2004 remote, with the "key clamshell" removed:

63688ca0.jpg


Remove the back cover to access the battery inside the remote:

657bf857.jpg


THIS is the transponder chip:

b703f158.jpg
 
Here is another picture showing the key that I have been using along with the various parts. I tried to start the car again this morning and it would not start. This is not a good sign as it has always eventually started when this has happened before.

It appears that there is no way for the transponder to fall out so I am guessing whatever is on the car side is no longer receiving the signal.

Not sure what my next step should be.

I just put 4 new tires on my LC (4 days ago) so cash flow is tight. Any suggestions or advice is greatly appreciated.

Mark
key3.webp
 
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Andy- Mine does not look like that :confused: I would pull my key apart but everything is being held together by the casing and don't want to reposition everything. I'll pull my junk key and take that apart and take some pictures.
 
Cathar_Knight

Hold the remote (part with buttons) flat against the dash as close to the key hole as possible while you insert your key and try to start the truck. If that doesn't work, hold the remote flat against the head of the key and again try to start the truck.

If it doesn't start, then you probably have immobilizer/security issues that will need to be investigated. If the truck does start, then you need to buy a $10 clamshell key off of eBay and get it cut, then put your remote in the new key. It's likely that the transponder is just too far away from the sensor.

Ryan: I think they changed the internal design in 2004. It still works the same. On mine, I can remove the transponder chip without disassembling the remote piece further than what I pictured and the transponder travels with the remote. Not sure about the earlier ones...
 
I called the local dealership and they said that they suggest having the vehicle towed in and they can try and do a “hard reset” on the system. $165 yikes! Additionally they suggest getting the real key (about $300) – yikes. If those don’t work then they would need to replace all the modules associated with the security system. The price? About $1500-$1800 in parts and another $200 to $300 in labor – YIKES !!!!!!

Anyone have any other suggestions? Please !
 
Cathar - I have the same key FOB as you. My guess is that your FOB is no longer working. If I understand your post above correctly you have two of these 3 button keys and neither are working? Do you have a non-button "valet" key? Have you tried that one? If so, and it doesnt work... then there is something else going on besides the keys. If you do not have one of those "valet" keys, you could order one from ebay:

Valet Key

Then follow the steps in the link above to try and program it. Sounds like people have had success that way. I have not had to do that yet.

If that works, then you problem is solved and you could either order another and do the same and have two working chipped keys and forgo the keyless entry. If you really want to keep the keyless entry option, I would still try the above option first to rule out it is something other than the key. Then go on ebay and order a new uncut three button key and program that as linked above.

Three Button Key

Good luck!
 
I will go back and try various options but I think I tried most last night and had no joy.

I really cant consider a $2000 bill at the moment. Can the transponder be by-passed or tricked somehow?

Mark
 
In the 6 years or so I have been on here, I have not heard of any one tricking or by-passing the system. Just of people ordering a chipped key like I linked above and programing it themselves or paying some one to.

I really dont know the security system on these nor how they are reset. But have you tried resetting your ECU yet? May not have any results... but wouldnt hurt either. Disconnect your negative battery terminal for 10-15 min. then reconnect. It will erase your radio presets....

I will try and look in my FSM's to see if there is anything as well. But, that will be later this afternoon before I get a chance.
 
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