Disco 2 D2 Immobiliser issues

[chu017]

morning all, I have a D2 V8 and am currently getting it ready to bobtail and make into a tray back with a Longranger kit.
It was running and now having carefully moved all the wiring looms forward to the B pillars the Alarm/ Immobiliser is stuck on. I have put new battery's in both keys, the vehicle battery is fine, I do not have the EAK code.
Sometimes when I unlock it with the key from the drivers door the alarm goes off when I open the door but sometimes alarm isn't until I put the key in the ignition.
doing the 1st step of entering an EAK code where you gold the turn of the key for 5 seconds and should get a beep docent happen so even if i can get the EAK from LR I am not sure it will help.
can anyone offer any ideas or advice?

I have found the immobliser bypass unit from Dixon Fabrication but that is only for a TD5 engine not the V8

 

[sierrafery]

Hi, check if you didnt disturb the wiring to the RF receiver. As long as you played with the looms it's most probably a continuity issue on some circuit involved in the alarm function.

what immobiliser bypass did you see for Td5? cos if it's that security signal emulator it should work for any engine as long as you have a proper diagnostic tool to make the ECM learn the security code

 

[chu017]

Hi, check if you didnt disturb the wiring to the RF receiver. As long as you played with the looms it's most probably a continuity issue on some circuit involved in the alarm function.

what immobiliser bypass did you see for Td5? cos if it's that security signal emulator it should work for any engine as long as you have a proper diagnostic tool to make the ECM learn the security code

by RF receiver do you mean the one on the right side boot window? the AM/FM receiver?

this is the bypass I found
https://dixonfabrication.co.uk/index.php?route=product/product&path=92&product_id=168
I emailed the maker and he said no no good on the V8

 

[sierrafery]

by RF receiver do you mean the one on the right side boot window? the AM/FM receiver?

NO the alarm RF receiver in front of the rear sunroof area(even if no sunroofs are fitted it's there), google out "Discovery 2 alarm receiver"

this is the bypass I found
https://dixonfabrication.co.uk/index.php?route=product/product&path=92&product_id=168
I emailed the maker and he said no no good on the V8

As long as they say
"THIS BOX WILL IMITATE THAT SIGNAL SENT FROM THE BODY CONTROL UNIT TO THE ECU THEREFOR TRICKING THE ECU THAT THE ALARM IS NOT ACTIVATED AND ALLOWING THE ENGINE TO RUN EVEN IF THE BCU IS NOT CONNECTED" it should work on any engine cos that signal is unique for each BCU as the BCUs are not engine dependant but fully programmable just that the signal wire should be connected to the V8 ECU's security input(C0637 - 33) ... however i dont know what kind of emulator they have which would work only for the Td5 or they have no ideea what device they sell... or i dont get the logic of it which is also possible

 

[chu017]

I may get one of the bypass modules as a test anyway, but then need a nanacom aswell.

I have moved the RF receiver but did it carefully and having just looked at it it defiantly doesn't ground to the roof so is presumably the older type.
no sunroofs in this car and it worked before i moved wireing
would that reciver not working prevent the car starting is it only related to the buttons on the key fob?

you dont happen to be anywhere near peterborough or grantham uk do you?

 

[sierrafery]

would that reciver not working prevent the car starting is it only related to the buttons on the key fob?

Most probably you disturbed a continuity somewhere when you moved the looms IMO. The RF receiver is working with the fobs when they are "excited" by the passive remobilisation exciter coil which is around the ignition barrel too not just on buttons, the receiver used to be grounded through the retaining bolt cos it's supposed to have a eyelet connector there

as about the secuity code, it's sent by the BCU from C0661 pin 10 (LGS wire) and as you see it's one wire no matter to which ECM it goes but diagnostic tool is compulsory but once you have that you can disable the immobiliser without using any "magic box"

 

[chu017]

hear are some photos

the connections on the 3 pin connector are black/brown, purple/gray and a black
the black has a joint to a thicker wire that goes into the loom (ground?)

the case is defiantly not earthed

 

[chu017]

so I need to work out the earth on that module and may be going in the right direction.

 

[sierrafery]

Ah, OK it's the early receiver i see now... if the fobs worked before start suqeezing and jiggling the looms while pressing the fob's button maybe it kicks in at a point also check if you have earth on that black wire and if not splice in with one

 

[chu017]

Ah, OK it's the early receiver i see now... if the fobs worked before start suqeezing and jiggling the looms while pressing the fob's button maybe it kicks in at a point also check if you have earth on that black wire and if not splice in with one

ok cool the black wire I can work with, I will get a deffinate good earth to it and go from their.
presumable the other 2 are a +12v feed and a signal line?

 

[sierrafery]

Yes, the purple/grey is the power supply, you must have 12V across that and the black one

you dont happen to be anywhere near peterborough or grantham uk do you?

i'm in Romania

 

[chu017]

Yes, the purple/grey is the power supply, you must have 12V across that and the black one

i'm in Romania

You sir are a genius, I owe you a beer for sure.

This turned out to be the culprit. so no fault except the one I created for myself.
Reconnected the body earth connector to the bodywork and all is working again .

Thankyou

 

[sierrafery]

Welcome, i'm glad it's sorted, from now take care if you work with looms to not let earths in the air, they are very important