So i bought an XK8 as a project last week in Norway. The car is imported form the US and was sold cheap because the car wont start. When you turn the key nothing is happening, but only the fuel pump is going. We checked the fuses and found alot of blown fuses. as we replaced them they failed ammediatelly.

the fuse to the ABS pump fails ammediatelly as we replace it. its only the rear ligths that works when the ignition is on but the dashboard and headligths is completely dead. Is there anyone who has got a clue of what it can be? Would help massively

 

Elias,

You’re a brave man to tackle this car with, what sounds like a bad case of electrical gremlins .... maybe due to flood damage. Maybe someone did some welding on the car, without disconnecting the battery, and blew some control modules.

We’ll need a lot more details, especially which fuses are bad. A bad ABS module shouldn’t stop the car from starting though. There’s an electrical guide in the Stickies thread at the top of the list of threads.

Have you plugged in an OBD2 reader to read DTCs? If you get nothing, then it’s a lot of electrical shorts blowing fuses. You’ll need to check wiring looms, pin by pin, then check each control module, and the latter are both difficult to find and even more difficult to install. You’ll need the VCAT label in the trunk, which lists the modules you have, to know what modules you have if you’re sourcing replacements.

 

David's comment about flood car is probably very accurate. Flood cars can not be returned to the road easily in this country, so many are shipped to other countries. In some cases, with fresh water flooding, recovery is not too difficult. But when exposed to salt water due to hurricanes, it is often nearly impossible once corrosion of the electrical system has begun.

I hope your car is not going to be a difficult case, and with the assistance of the forum members, you will be able to bring another XK8 back from the dead.

 

David, i checked the obd 2 and only found 3 things like the mirrors, my obd reader told me it had problems to connect to the ECU

 

Elias,

It's not a good sign that your OBD2 reader can't read the ECU. First thing's first - here's a 2013 link to how to check ground on the ECU at the connector.
https://www.jaguarforums.com/forum/x...-ground-90481/

Here's another link to a recent ongoing thread about the ECU and the difficulties in replacing it.
https://www.jaguarforums.com/forum/x...cement-225633/

The X100 car has multiple control modules which all talk to each other on the CAN bus. The includes the dashboard behind the steering wheel. I think you'll need the Jaguar Electrical Guide for your car (use the Forum Search Function) and start checking the systems where their fuses that are blowing.

I would also start looking locally for an electrical whiz who can inspect and repair electrical PCBs. It's always safer to repair what you have, as introducing new modules always has the risk that a previous owner has re-freshed it with software upgrades not compatible with your 99 MY.

If you think you have a flood damaged car, the best case scenario is that you've corroded shorts either in the wiring looms or on the PCBs in the modules. Worst case scenario is that modules are damaged beyond repair.

Good luck.

 

Don't believe the interpretation on the reader. If you have downloaded the repair manual JTIS21 the electrical section has the code interpretation, and posting the actual codes here so that others can see them is a good idea.

 

^^ What he said.

Start tracing with the aid of JTIS what the blowing fuses supply power to, or post the numbers & locations here and we can most likely help.

What year is your car?

 

I attach a PDF of the fuse chart.

+1 to Michael - plus we'll need more info on what options you have on the car. Convertible/Coupe, Adaptive suspension, Music amp etc

 

Today i checked out some of the fuses and since the whole cars electrotics is dead i had to locate the manual switch hidden in the xk8 logo. And i found a fuse that was blown in the boot i replaced it to see what happen and it failed after maybe 5 seconds and then it started to smoke and smell. So we tried to locate it but didn’t seem to find it. We had a theory that because the ABS pump is dead the car has a safe thing to keep the car from starting.

i need some help to understand what PCB module is and JTIS. Thank you

 

Sorry,

When I said PCB, it’s the abbreviation of the printed circuit board (sometimes known as motherboards) which is what the chips, capacitors, resistors etc sit on within the control modules.

Often, in the case of water damage, the PCB traces are shorted out/connected erroneously with deposits.

 

JTIS is a Jaguar technical publication supplied as an installable PC software application, and is available for download from the stickies at the top of the main forum page:
https://www.jaguarforums.com/forum/x...ts-data-29800/

As David says, we need to know the year and type of your car:- there are many detail differences across the years (including fuse locations) , otherwise we're just guessing.

ABS won't prevent the motor starting.

The security module is positioned low in the boot, so is an early candidate for water damage

 

JTIS21 is the factory repair manual. You can download it from a Sticky on the XK8 home page. I believe someone has a mediafire download, not sure how to access that.

 

The car is a 1999 xk8
i’m not that sure of water damage because if that was the case i would have probably seen signs of it dust for example. The does not look like it has been underwater

 

Hi Elias,

I've attached the 99 electrical guide and OBD reference from JTIS to get you started. For completeness sake, is she a coupe or convertible?

Do let us know what codes the car is throwing. In the meantime I guess you can pick one of the blowing fuses and follow where it leads.

 

The car is a convertible

 

Ellias,
You probably should say which fuses are blowing. I'd trace then 1 by 1 to see where the (common?) Short circuit is.

Look at the power diagram in the manual Michael posted for you. Battery feeds high power protection module. It feeds all 4 fuse boxes.

Is there a common fuse box in trouble?

Would you be comfortable disconnecting all 4 fuse boxes, then reconnect 1 by one. connectors are listed in the diagram.

Disconnected fuse box. Measure fuse to ground, any shorts?

Any fuses blow inside each as connected? If yes trace it: what component does that fuse feed? What made it blow?

BTW, blown fuses: ignition or battery?

John

 

Thoughts

• The security module in the trunk is known for spectacular failures. Easy to reach, easy to open and check.
• The standard OBDII protocol is only available over ISO-9141. Make sure your scan tool is not confused by the (normally) working/active CAN and SCP networks because OBDII is not available there.
• jagrepair.com is your friend, read-up as much as possible. In particular, read up on the structure of the data networks and what function is housed in what module. Then, from the symptoms, try and figure out what module is involved. Check the TSBs, too!
• Confirming all 3 data networks are working (CAN, SCP and ISO-9141). You can test/debug with a cheap ELM327, but you will likely need a Jaguar/Land Rover scan tool sooner or later.
• Assume this car has been worked on before, and that maybe incorrect parts have possibly been fitted (incompatible XJ control modules, or programmable modules not configured for this car) or that someone bent pins while messing with connectors.
• Check for blunt wire hacks (alarm system, custom stereo, satellite radio, etc.), animal damage (mouse, squirrel) or water damage for more clues.
• From memory, the early cars are subject to electrical problems from a short in the upper console, I believe preventing the car from starting (multiple modules on the same fuse).

Best of luck, keep us posted.

 

Could you tell me where the upper console is located? That does sound right

 

Elias - Well lots to think about with good advice from other forum members above.

Here's a link to the eminent Rev Sam's youtube video showing access to behind the upper console dashboard where the Dashboard Instrument Cluster collects a lot of info on the CAN bus.

As mentioned above, the ABS module shouldn't stop the car from starting.

You said you replaced a fuse in the trunk box and smelt smoking. That's not good. Which fuse was it?

As suggested by fmertz, have you checked the security module, which is located under the trunk fuse box. Do you have the VCAT label in the trunk listing all the modules that should be in the car. Is this module you have correct for the car? Crack it open and check inside especially the condition of the PCB. You have multiple modules for the start, and I attach an electrical diagram showing what is involved.

Good luck.

 

You all know the xk8 very well, but we know very little about jaguar’s in general. But we are not born with 10 thumbs. If you could explain what CAN or JTIS and things like that it would be alot easier thanl you here is to photos of the car