the car: 98 gs300
the problem: my keys were stolen
the solution and new problem is as follows:
i called a local locksmith to rekey the entire car, and rreflash the computer so that they can make up another set of keys for me and program them. after they feflashed the computer, the car woudnt start. thay say the computer isnt reading the new keys to be programmed. 10 reflashes, and the same thing happens, nothing. any ideas? anybody?! somebody!

 

After reflashing, the ECU needs IIRC THREE keys to be programmed as master. This is from the top of my head because it's been a while since I did this to my car...

What you do is:
- flash ECU
- insert key 1, BUT DO NOT TURN!
- remove key 1
- insert key 2, BUT DO NOT TURN!
- remove key 2
- insert key 3, BUT DO NOT TURN!
- remove key 3.

The security light should change after this. Insert one of the keys, and the car should start.

 

Man is there anything that the people on this forum can't answer....?!

 

Clublexus heads>Lexus techs at stealerships

 

and most certainly > lexus owners club weiners.

 

After reflashing, the ECU needs IIRC THREE keys to be programmed as master. This is from the top of my head because it's been a while since I did this to my car...

What you do is:
- flash ECU
- insert key 1, BUT DO NOT TURN!
- remove key 1
- insert key 2, BUT DO NOT TURN!
- remove key 2
- insert key 3, BUT DO NOT TURN!
- remove key 3.

The security light should change after this. Insert one of the keys, and the car should start.




this was the process we tried everytime. the car still would not start. the computer isnt reading any keys at all. security light isnt changing.

 

This leads me to believe that:

1. The keys the locksmith are using don't have the transponders in them? (I had to pay extra for these from the locksmith). Other aftermarket keys that locksmiths have are just lock-out keys. The key I got from the locksmith has a fat casing compared to the normal casings of aftermarket keys.

2. The locksmith may have flashed the wrong CMOS chip on the ECU? The process of flashing this chip is basically "zeroing-out" the information on it. In other words, just erasing it by changing all the bytes(or bits, I forget) to 0's so make sure that's what they are doing.

It's common sense for anyone doing any type of programming of chips to back-up the information on it before making any changes. So if the guy did erase the wrong chip, hopefully he has a backup. If not, then you may need to get another ECU.


One more thing, did the locksmith desolder the chip to put it into the programmer? Or did the programmer have an "aligator-type" plug on it so the removal of the chip wasn't necessary? Depending on the answer, I may have another possible conclusion for you.

 

they used an aligator clip, so they didnt desolder the chip. they also used the fat transponder blank keys for programming.

 

Is it possible for you to remove the ECU, remove the cover and take a pic of the circuit board and highlight the chip the guy flashed? You may need to wear an anti-static strap and ground yourself to the ECU to prevent electrostatic damage. This leads me to another question:

Did the locksmith wear an anti-static strap while working with the ECU? Usually this shouldn't be a problem, but there's always a possibility of electrostatic damage.

Maybe there's something else wrong. Do you have an aftermarket alarm?


Sorry for all the questions, I'm just trying to help you troubleshoot the problem.

 

no problem with the questions, but you wouldt beleive this.......... the car starts now, and heres how. after the first week of failed programing and the computer not reading any keys, the locksmith told me that he talked to the person who made the reflash program that lives in the states, and that he said 2% of 98 lexus gs's and toyota camrys have this same problem. The solution is a clone chip that will clone something, but the car should start right away. it looks like a larger lexus blank key, and the blade can be removed from it. the locksmith just rested the clone whatever key on top of the newly cut key thatg couldnt be programed, and started the car one crank. i thought i was dreaming. i didnt hear it turn over for 2 weeks. After learning the clone setup works, its a series of maneouvers to get the lexus cut key to pick up the programing from either the computer or the clone key. im not sure how exactly it works but the keys then didnt want to program to the car. after the locksmith made another call to the maker of the clone whatever, it was found that the instructions for the programming were incorrect. he told him the right way to do it, the locksmith tried it, and the keys were now programmed to the car. case closed. i hope with our posts we help others out who ever encounter this problem..........thnx for taking the time to help me sorthis thing out too.
Modena-6

 

i was pretty sure the only way to program the keys WAS to turn them in the locks at least thats how it was on all the fords/lincolns/mercurys/mazdas and most of the preowned vehicles i came across working at the dealership i used to work at.

 

When I had my ECU flashed, I remember exactly not to turn the key during programming.

Glad Modena got his car running again. So you got ALL of your keys to start the car right?

 

2 starting and 1 valet