He is the guy I got my widget from.
Clever bloke, he said at the time he was working on the FOUT box/board.
J
P38A GEMS signal for ok to start.
- Thread starter marjon
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He is the guy I got my widget from.
Clever bloke, he said at the time he was working on the FOUT box/board.
J
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According to his facebook page, he has closed down RPI now, but might respond on FB.
You edited your post.
Yes it’s what I have and is the same guy in your last video link.
J
Grrrrrr
Technician, Bodgit & Scarper Ltd
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Its not the remote code thats the issue its the next step that comes out of the BECM to the ECU to say its ok to start.
I also belive that the ECU sends some sort of acceptance that it matches which then allows the BECM to allow cranking/fuel/spark.
Done a lot of reading and I may have misremembered some of that
Need to check if that signal from the BECM is sent when the fob is used to open or when the key is turned in the ignition.
There is an option to just put it in a working GEMs car and start it, then remove the ECU good to go standalone. Probably have to put the original in learn when replacing. But there is a distinct lack of RRs here.
J
Yes, I realise that but those 3 know the procedure all the way from capturing the code to sending a code to start the car.
iirc the Thor and diesel are similar in that there's a single code held in the BECM and the chip in the EMS. GEMS is different in that it uses a rolling code that is incremented each time. Marty once showed me how the codes were stored and sent. They weren't encrypted. I think it was simple hexadecimal but I don't know how it was transmitted. In the back of my mind I have the word K-line but my memory isn't reliable.
Grrrrrr
Technician, Bodgit & Scarper Ltd
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K-line rings a bell.
Datatek
Well-Known Member
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Thankfully, I have never had anything to do with the V8 but I have always understood that the immobiliser for the V8 ECU's was a rolling code not a fixed code like the diesel is. The code is transmitted from the BECM on a serial line (K Line?) as four 8 bit bytes in hexadecimal format. Not difficult to emulate if it's a fixed code, not so easy if it's a rolling code as it is necessary to know the increments used for the code.
Grrrrrr
Technician, Bodgit & Scarper Ltd
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- Buckinghamshire, UK. ('95 DT)
GEMS is rolling code. Not convinced the Thor is but never played with one. I also don't know if it just sends the code to start or whether it continually sends it. Both strategies were used on the diesel depending on the year.
Marty scratched the protective coating off the chip and then used a sort of CPU socket and pressed it on top of the chip. The socket was connected to his laptop and he was able to read the code off the chip.
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It can’t roll that much. When out of sync Nanocom or testbook puts GEMS into learning mode. It then learns next code from BECM. If it rolls it can only go from 1 to 65534. FFFF or 65535 tells GEMS to go into ignore mode.
Either the F-out module or Nanocom experiment is the way to go to get GEMS working standalone
Either the F-out module or Nanocom experiment is the way to go to get GEMS working standalone
Datatek
Well-Known Member
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It's the increments used that matter.
Grrrrrr
Technician, Bodgit & Scarper Ltd
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Yes. Although as you say, the Morgans Owners club might know more.
My belief is the Gems is a rolling code, how it does this when it sends the last stored code to the ECU and the ECU confirms, I dont know.
The Thor (Bosch) runs the same sercurity as the Diesel with a fixed code that can be seen and replaced into the BECM to resync the 2 if needed.
The Gems has to go into "learn" and takes the first code it gets to sync.
I may give the 10AS system from the Disco a good looking at, as this works with GEMs and maybe easier to do on a bench.
I only need to send the code 1 time to make it a standalone ECU.
J
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- Near Heathrow.
Unfortunately the P38 Nanocom doesn't show the GEMS immobilisation code, so it's probaby gotta be a bench job.
The Nanocom has the Lucas AS10 option for cars that use it, which appears to show the code, but it would need someone with an AS10 & Nanocom to confirm if it rolls & by what amount ?
AS10 appear to cost more than the F-Out box on eBay, so maybe that's the best route for your requirement ?
The Nanocom has the Lucas AS10 option for cars that use it, which appears to show the code, but it would need someone with an AS10 & Nanocom to confirm if it rolls & by what amount ?
AS10 appear to cost more than the F-Out box on eBay, so maybe that's the best route for your requirement ?
Yes Gems dosent show code, which is why it needs learn mode.
"AS10 appear to cost more than the F-Out box on eBay, so maybe that's the best route for your requirement ?"
Confused a bit now.
I thought AS10 was the alarm module used on the discovery Gems cars (and others)
Did you link to an F-Out box or the same widget that I have?
J
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The AS10 is the alarm & fob decoder, etc for car that use it. It has to do the same job as the BECM does with GEMS. Looking at the Nanocom guide for it, it appears to have better accessibility to the features including the GEMS Immob code.
If your widget is from Simon, it appears to do the same as the LR F-Out box. Both will put GEMS into standalone mode, so it doesn't need anything from either the BECM in a P38 or AS10 in other cars.
However be aware I have never played with either, so only have Simons video & the LR Tech doc as reference.
If you already have the boc from Simon, give it a try on a GEMS ECU.
If your widget is from Simon, it appears to do the same as the LR F-Out box. Both will put GEMS into standalone mode, so it doesn't need anything from either the BECM in a P38 or AS10 in other cars.
However be aware I have never played with either, so only have Simons video & the LR Tech doc as reference.
If you already have the boc from Simon, give it a try on a GEMS ECU.
Thanks for looking at the AS10, I thought the same. May look into this further.
I have the instructions from Simon and they clearly state that I need to give it 1 start signal to make it standalone. It was before he started working on the F-out box.
J
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Can't remember if you said you have a Nanocom or not ? If you do, then it should be easy do get the GEMS how you need it, before building the other vehicle.
