XJ8 wiring diagrams

[330p4]

Can anyone tell me where i can get wiring diagrams for XJ8 in paticular the engine & transmission ecu's i am looking to transplant the engine & box into a different car. Any one who has done this i would appreciate comments i believe the engine & transmission ecu's talk to each other was hoping to get the harnesses out hopefully not to many connections to make thanks in advance for any help
Ian

[Fullmel]

The ecu and tcu communicate via a can network so I don't think this can be done as other modules are needed for the can to work instrument pack ect.

[330p4]

Thanks for the reply but i dont need to run the jag insts just want to get engine & gearbox working i have an electronic solution to the insts i know there is a problem putting a manual box on & running std engine ecu but i want to run box & engine together. Dont want to run an after market ecu as this will need motec or other expensive ecu due to vaiable cam timing
Ian

[X100]

This might help
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&am...

[Fullmel]

But the instrument pack is needed for the can network so the engine can talk to the gearbox.
I hope you will be able to get around this problem. But I'm not sure you will beable to.

[330p4]

Are you saying the Canbus drivere is part of the inst pack electronics? If not it is just a two wire serial bus so the engine & box should be able to communicate. Thanks for all your comments
Ian

[Fullmel]

It has the termination resistor incorporated in it so without it it will not function correctly

[Tame Technician]

The car normally has a number of modules on the CAN bus, ABS, ECM, TCM, IPK + SRS etc. Not just gearbox ECU (TCM) and engine ECU (ECM)

You can take any number of modules out of the network as long as the termination resistors are still in, but as above they are in the instrument pack.

SO you will have to wire some in some how, I dont know how you do that, but I do know Motec and other stand alone ECUs can work without the rest of the CAN network modules, so must be posible.

I suggest you have a google.

I'm sure someone on hear has a manual converted XK8 with a motec ECU, they may know.

Edited by Tame Technician on Thursday 12th August 01:00

[330p4]

I think all you have to do is fit a termination resistor anywhere on the bus does anyone know if the looms come out in one with just power supply connections required thanks again
Ian

[Zulu 10]

Sorry to rain on your parade, but a quick look at the JTIS reveals the data packets that the ECU and Traction Control Module expect to receive via the CAN Bus.

They include Vehicle Reference Speed and (all four) individual wheel speeds which come from the ABS/Traction Control Control Module.

I would be very surprised if the ECU and TCM will operate other than in a reversionary mode if they do not receive that data.

Though I suppose that if you knew the format and scaling (which is easy enough to work out using a bus analyser on a working car) then these could be generated by an emulator.....

[330p4]

Dick your not raining on my parade this is exactly why i posted to see if i am wasting my time or just a load of grief thank you all.
Ian

[robgee1964]

Zulu 10 said:

I would be very surprised if the ECU and TCM will operate other than in a reversionary mode if they do not receive that data.

The backup strategies are a bit more advanced than that these days, I'd only expect to lose those functions which rely on the missing data. So for road speed loss, no traction control etc. If the donor car is still running, you could try backing out the CAN wires from the ABS ECU, and see how it performs (The ABS is likely to be the speed signal source)

As someone else noted, CAN bus will be fine so long as your termination resistors are present. Some networks have a single 68R resistor in parallel, other setups have two, 120R resistors one at the most remote nodes. It won't like having no resistor at all, but worst case you just need to order one from RS and solder it across the bus wires.

What *could* scupper the whole job though is the vehicle security system. On a lot of modern cars the fuel injection ECU simply won't operate unless it receives the correct code from the alarm, or BCU, or whatever.

Connecting a bus analyser on is certainly possible, although might not tell you a great deal unless you know the message formats etc.

Edited by robgee1964 on Friday 13th August 10:37