nlt999

Hi!
2007 Lexus RX350 - Trying to register new keys using techstream. Everything goes normally until the actual registration step.. says it is registering and timer starts the countdown, then after several seconds it stops with message:
"Key Registration has failed. The communication error occurred between the key and the ECU".

DTCs logged are B2794: Unmatched Encryption Code B2795: Unmatched key Code B2798: Communication Malfunction No.2

Tried it using two new keys.... same failure message.

I WAS able to successfully program the remote buttons on those same two keys using Techstream.


Anyone have any knowledge/ideas about this please??
Thank you! Nick

Bytheway

Hi Nick
There may be a limit to the number of keys you can program.
I had a problem programming the entry portion until I finally deleted all the previous registered keys.
I see in a new post that you entered, the original poster was unsuccessful even after unregistering all keys. He hasn't respondent yet.
If you haven't tried that, give it a shot.
Try it and good luck

fleaflop

I have the same issue as NLT999, except I have room for a new key but the exact same error message and unable to register new key.... these are aftermarket keys.
anyone have any ideas? thanks!

TW99GS300

What key did you purchase specifically? Most aftermarket keys come with the 4C transponder. The transponder for the RX350 is 4d67

nlt999

Wow... Sounds like good info! How would I identify which transponder is in a key? The ones inside the keys I bought are unmarked...... nothing at all, just a plain black case. The original key has a transponder marked:

FCC ID: HYQ 12BBT
IC: 1551A-12BBT
DENSO

I would appreciate any info you have!

Nick

guyrat7

Sorry to introduce a red herring to this conversation but may I know how you got the obd cable installed on your laptop/pc? I am having trouble getting the drivers installed. Even if the drivers get installed, the cable is not recognised. Any tips about getting the right drivers for the cable? Thanks!! (i use win7 64bit, used MVCI drivers for Toyota TS - the drivers explained here > http://blog.obd365.com/2014/03/10/ho...ows-78-64-bit/)

Lexuswiz

iTrader: (1)

I'll agree with this, I just bought 3 generic 4D blanks (no remote) off ebay for my RX330 and they all programmed without a sweat using TS10. I had more trouble finding a locksmith that would do the Lexus cut cheaper then the dealer who charged me a fortune without programming. I believe the 4C is more used with Toyota's. Unfortunately my keys have no marking on them so I can't provide the FCC or IC.

TW99GS300

4C are used in the 2GS and 1IS. Around the 98-05 era.

TW99GS300

It's in the link you pasted on there.
Also there's a newer 10.34 version instruction.

Braz60

My wife's RX330 key casing broke the part that houses the FOB. On Ebay if I give them my key code they can cut me a new key and I would put my FOB into this new key casing.
My question is do I need to get anything reprogrammed for this new key to work? Or as long as I have the existing FOB it should work?

SkiMe

I was at the Toyota dealer and some guy was getting his key programmed. Said it would take an hour to do it. So I asked, can you re-program any key and he said once a key has been programmed to a vehicle, it is locked to that vehicle. So even if they "wipe it" and say its a blank key, it will never learn the key to a new car...only the original one it was initially tied to. He said that's a problem with getting them online or eBay.....they might of been programmed already at one point.

I don't know if there are other ways but I found that interesting, nonetheless.

Lexuswiz

iTrader: (1)

You do not need it programed if you are only swapping the shell. It's when you have a brand new transponder (chip) is when you need to program it.

This is interesting to hear. But I can tell you the time it takes is false. I've programmed many Toyotas and 2 Lexus' in under 15 minutes: standard key, g key, and smart key. The thing is the dealer charges in hour increments so you're getting railed for something that takes 15.

But I've never tried programming a used key from a different car, might need to try that one. I've been able to reprogram an existing key of that specific car with no issues since I lost the key, got paranoid, then found it months later.

Bytheway

It sounds a little suspicious to me. I did just that and had no problems programming a used key fob (both entry and starting). I'm in no way an expert, but I think you are programming the car's computer to accept the key and not the key to recognize the car. At least that's how I was able to do it to my 2007 rx350

TW99GS300

The way Toyota system works is that the car learns the code from the transponder.
I seriously doubt the new car will know if an old key has been programmed to another vehicle.
Perhaps it is a security issue if the used key was programmed to another vehicle and was not erased from memory.
Or the service department is trying to make a sale.

Braz60

Could someone please clarify is the transponder chip located in the key FOB (The buttons that open and lock the doors) or is is located in
the actual metal part of key that you stick into the ignition / car door?
Thanks