So if I buy a junkyard ECU from another LX470 with master keys, will it just work?

[nukegoat]

Or is there some other dealer programming necessary to make things work ok? Are all ECUs (from the same year and model) essentially the same or were they varied based on options (e.g. AHC, night view, bluetooth phone, nav, etc)

 

[fj55-100]

all ecus are different , for a number of reasons , best to stick with the part number on yours . ( the keys it comes with will not turn in your lock . so the will electrically unlock the ecu to add your keys as masters . it take a little work to remove the pick up coil from the key cylinder in your truck to start the process )

 

[BEG]

Is the problem with the ECU or with the key(s) (more likely, lackthereof)? In either case, you're probably safest sticking with the same part number for the ECU. If you have keys that work with the ECU but not the lock/ignition cylinders, you can combine the good chips with the good blades.

 

[ScubaJon]

i cant say if the ecu will work without some programing from the dealer, but as far as the keys not matching.

All you have to do is take the chip out of the key that came with the ecu and use it to replace the one in your current key that turns the ignition.

 

[Trunk Monkey]

Paging resident ECU expert @Mauser

Also, the chip is inside the molded plastic, not sure how you're going to swap keys.

 

[nukegoat]

i cant say if the ecu will work without some programing from the dealer, but as far as the keys not matching.

All you have to do is take the chip out of the key that came with the ecu and use it to replace the one in your current key that turns the ignition.

Right - so assuming it's the same part number I can...

1) buy a junkyard ECU with at least 1 master key
2) plug it in
3) then swap the junkyard ECU key chip over to a key that's cut for my lock cylinders
4) Cut new keys with new chips and follow the programming method to add additional master keys to my ECU

Do I have this process correct?

 

[Mauser]

Right - so assuming it's the same part number I can...

1) buy a junkyard ECU with at least 1 master key
2) plug it in
3) then swap the junkyard ECU key chip over to a key that's cut for my lock cylinders
4) Cut new keys with new chips and follow the programming method to add additional master keys to my ECU

Do I have this process correct?

Yes, that will work on earlier models. Anything after 2004 will need to have the vin written to it.

What year is it? Are you just looking to make keys?

 

[nukegoat]

Yes, that will work on earlier models. Anything after 2004 will need to have the vin written to it.

What year is it? Are you just looking to make keys?

Its a 2004... so should I just hack the eeprom instead?

And I have no master keys so I cant use new master keys

 

[Mauser]

No. You can reseed that one. If you have techstream it can be really simple.

 

[nukegoat]

No. You can reseed that one. If you have techstream it can be really simple.

I can get techstream. i dont need a master key to reseed? Sorry - this goes against what I understood in my research but its good news i guess. Will it be obvious if I get my hands on a copy of techstream? Or is there more info I need?

 

[Mauser]

If you get techstream go to the immobilizer ecu. It should give you an option to reset the ecu in case of lost keys. It will require a passcode to do. It will give you a 96 digit seed number that you copy and enter into a calculator online. I can help you with a passcode if you decide to try it yourself.

It is best to have 3 keys cut and ready to program when you do this. It really isnt difficult at all.

 

[nukegoat]

If you get techstream go to the immobilizer ecu. It should give you an option to reset the ecu in case of lost keys. It will require a passcode to do. It will give you a 96 digit seed number that you copy and enter into a calculator online. I can help you with a passcode if you decide to try it yourself.

It is best to have 3 keys cut and ready to program when you do this. It really isnt difficult at all.

Ok. I am on it. Convinced. Thanks!

 

[Mauser]

Any luck?

 

[nukegoat]

Any luck?

Havent done it yet. Need to get keys cut still.

 

[nukegoat]

Any luck?

Alright - well, I tried unsuccessfully tonight. Got the paypal passcode fleecejob stuff for the online calculator, spent 16 minutes having it reset. I had the new key in the ignition initially and it didn't throw any codes, but now that it's in programming mode it seems to pop up a B2794 with the new keys (but not with the old valet key).

I assumed this was some sort of chipset mismatch but I took the new key apart and it has a 4d-67 chip in it... not sure what gives. Did any 04 LX470 still run the 4c chips?

 

[Mauser]

Alright - well, I tried unsuccessfully tonight. Got the paypal passcode fleecejob stuff for the online calculator, spent 16 minutes having it reset. I had the new key in the ignition initially and it didn't throw any codes, but now that it's in programming mode it seems to pop up a B2794 with the new keys (but not with the old valet key).

I assumed this was some sort of chipset mismatch but I took the new key apart and it has a 4d-67 chip in it... not sure what gives. Did any 04 LX470 still run the 4c chips?

I would have given you a passcode. Did you make your old valet into a master so you can just add keys instead of reseeding again?

It may need a 4D68 chip. I tried a couple of aftermarket key blanks when I re did my wife's GX470 and they wouldnt program, so I ended up buying the key blanks from Lexus and they programmed fine. I didnt have any problem with the aftermarket keys without the remote part, just the ones with the wireless remote in them.

 

[nukegoat]

I would have given you a passcode. Did you make your old valet into a master so you can just add keys instead of reseeding again?

It may need a 4D68 chip. I tried a couple of aftermarket key blanks when I re did my wife's GX470 and they wouldnt program, so I ended up buying the key blanks from Lexus and they programmed fine. I didnt have any problem with the aftermarket keys without the remote part, just the ones with the wireless remote in them.

I thought the passcode was seeded to a time or something so it changes every 10 min?
At any rate - i dont really want to buy lexus keys. You think a 4d68 chip will work?

 

[Mauser]

I thought the passcode was seeded to a time or something so it changes every 10 min?
At any rate - i dont really want to buy lexus keys. You think a 4d68 chip will work?

The calculator I use lets me pay once per vin and will give as many passcodes as it takes to get it right. You only have 10 minutes from the time you get the 96 digit seed code to enter the passcode into techstream.

I can't say for sure, but, yes I do think you need the 4d68 chip. Does your key have the ceramic wedge chip? If you have a cool locksmith in your area maybe you could just borrow a chip and try it.

 

[nukegoat]

The calculator I use lets me pay once per vin and will give as many passcodes as it takes to get it right. You only have 10 minutes from the time you get the 96 digit seed code to enter the passcode into techstream.

I can't say for sure, but, yes I do think you need the 4d68 chip. Does your key have the ceramic wedge chip? If you have a cool locksmith in your area maybe you could just borrow a chip and try it.

The new aftermarket key has a little black wedge inside it. The part number on that key seems to suggest it is a 4d67.

I can buy a few 4d68 chips but do they need to be instantiated or something? Or do they come from the factory with an immutable unique id?

Also - I am assuming the solid security light means the ecu is still in auto-reprogram mode or whatever. Other than putting a new key in the ignition and waiting for a light to go out, is there anything I was supposed to do? It doesnt seem to want to consider the valet key as anything other than the valet key (techstream doesnt indicate it is a master).

 

[Mauser]

The new chip will already have an ID. All the ecu does is record it.

If your ecu was reset and you programmed your existing valet key it should recognize it as a master. You should be able to exit programming mode by cycling the key on and off 5 times.