Hi Guys, well a very fed up 2005 XK8s owner, have done many jobs on the Jag including a full rebuild and powder coat of the rear suspension last year, and all's been fine. Put the car away at the end of September into the garage gone out weeks ago and display read "DSC system fault". Have been trying to fix it since. Started with:-
Replaced all abs sensors...............no difference
Bought crimping tool (£110) and replaced all abs plugs............no diff.
Was then told it was probably the DSC/ABS module, so removed the module sent it off for repair (£77).........answer came back, "NO FAULTS FOUND"
In the meantime I had found an exact replacement off eBay (£150) off a car built just 12 weeks in front of mine, connected it up bleed the system........no diff............so obviously the original module was ok.
The iCarsoft scanner on both units shows the yaw rate sensor, got another (£40) and fitted.....no diff.
Fit new Bosch battery.(£175)..........no diff
So the icarsoft scanner now shows 9 fault codes :-
C1279. YAW RATE SENSOR CIRCUIT FAILURE
C.1285. BOOSTER SOLENOID OUTPUT
C1295. STEERING WHEEL ANGLE SENSOR
U1901. CAN NETWORK 2 COMMS ERRORBUS FAULT - RECEIVE ERROR
U2527. CAN NETWORK 2 COMMS BUS OFF TRANSMIT ERROR
C1175. WHEEL SPEED REAR LEFT INPUT CIRCUIT FAILURE
C1155. WHEEL SPEED FRONT LEFT INPUT CIRCUIT FAILURE
C1145 WHEEL SPEED FRONT RIGHT INPUT CIRCUIT FAILURE

I can drive the car, bring up the wheel speed sensors and all are giving a signal to the scanner, I move the yaw rate sensor and you can see the voltage change.....so Im lost, to drive the car in the garage and alls fine, and now have all these horrendous codes. Have now spent over £600 and am worse off than when I started......ANY IDEAS GUYS. PLEASE

 

If you haven't done so already, clear the codes and then see which return.

 

Hi, yes just been out with the scanner, now have 10 fault codes, unable to clear any faults, as it states the fault has not been rectified. Have take the whole centre console out, plus audio dsc switch, unplugged, but still no good. I'm told if a wire is broken on the CAN system then it gives multiple errors, I'm also told to that the CAN system goes to and from every module in the car ad can be extremely difficult to find.

 

Agree that this sounds like broken can wire or faulty can end resistor

 

^^
The DSCCM is common to these codes. I couldn't find U1901, but here's U2527:



You can get to the CAN either from the OBD plug pins 6 & 14, or possibly measure across the J-gate module as you have the console apart. You're looking for 60 ohms, give or take ~5 ohms. If you read ~120 ohms, then one end of the CAN isn't terminated (open circuit somewhere). I'd guess the DSCCM end as you can start the car.

 

so the car has been garaged since September - any chance that rodents may have infiltrated the engine bay and decided to gnaw on some of the wiring? Just a thought

 

Hi Guys, many thanks for the quick response, any mechanical job on the JAG and I am fine, but electrics is a different matter.
However even I think I can do the resistance check between the two pins 6 and 14, and on a very bad note, I backed the car out tonight only to find a dead mouse at the far end of the garage. I have never seen one in 9 years since the house was built, so now if it is rodent related, this could be a horrendously long job finding the fault.
Still let's do the resistance check first, I'll keep you posted.
Many thanks
Bob

 

Bob, I agree these cars will test both your sense of humor and your sanity at times. You'll get through it with the help here just take a deep breath or two and carry on. Good luck!

 

Evening guys,
Well, it's good news , bad news, bought an OBII adapter cable, so I had no risk of damaging the pins in the plug with my heavy handiness. Soldered the cable to check pins 6 and 14 to test the CAN BUS, and also pins 4 and 16 to test voltage.

I was so sure, particularly finding a dead mouse I was going to get a reading of 120 ohms, but in fact got 61 ohms on the CAN BUS and 12 volts on the supply, ( thank you for the instructions Michael) so good news there is no fault on the CAN BUS wiring, the bad news is now I have no idea how to find the faults.



My son-in-law however works for Copart, on the JLS side, but lives a good way away, I have asked him if he can spare a weekend to come down and see if we can resolve this, as I have no idea as to go about finding the faults. Unless you know a way of finding where the fault is. I suppose I could plug in my original DSC Module (without connecting all the brake lines) and just see what I get, but as I said both modules give very similar fault codes. I love the XK8 and have had it since 2016, and although having a few mechanical repairs, this is the first electrical problem.............and what a bloody problem, but hey ho, its got to be fixed......somehow.

 

Hi,
I've attached a snip from JTIS which may help. It shows U1909, but is referred to by U2527 also (and the 2003 DTC list give identical information for both).

Where are you measuring the 12 volts?

 

Oh, many thanks Micheal, actually tonight I have found the DSC switch does not work, have stripped it down and it is definitely kaput, there are two on eBay but are £150+ ,as it comes as a complete module, but have emailed a company in Leighton Buzzard who repair Pcb boards, so am waiting for a reply.
The pdf looks quite daunting, but perhaps going at it steady I might get there, but will wait till hopefully I can get the switch repaired.
The 12 volt reading was on the OBII plug on pins 4

(chassis ground) and pin 16 (12volt power source).
Many thanks for your help, you're a star.
I'll update on how I get on.

 

When I get a DSC message it will go away after next start up. I suspect no voltage from sitting and not using the Battery Tender. I drive a little and it gets charged up and message goes away. You may have a deeper problem as you have pointed to the switch. But just in case, CHARGE IT! TM

 

^^
I used to get the ABS light on occasionally before I put the car on a tender.

That measured 12V exactly is low:- what do you read across the battery terminals with the ignition off? It should be around 12.6 volts at rest.

The non-functioning of the switch could be just another symptom of the problem. Note that it is depicted as a push-to-make (like the buttons on a remote control) on the circuit diagram rather than on/off latching, so will only indicate a short while it's pressed if so. It won't be the cause of any codes either way.

 

Tested all the switches with the meter but the dsc switch shows nothing on any of the pins, the battery I had on the car was good, but the Icarsrsoft scanner did show the battery, so bought a new Bosch, and the scanner shows the battery is ok, anyway will see if I can get the board fixed and go from there.

 

Anybody local to you who does electronics repairs can replace that switch for you if you are sure it is faulty - the challenge will be to find a replacement that is either identical or close enough to work. Time to start browsing:-

https://www.mouser.co.uk/c/electrome...tton-switches/

 

I'd still check the battery voltage at rest.

 

Hi Guys ,

Just thought I would post this to give hope to all of those out there if they are anything like me, who have despaired of ever getting the horrendous electrical faults I have had only 2005 XK*s coupe fixed. If you look at my previous posts you will see what serious codes I had and even with the help from other members still no joy.
Well, my Jag is sorted !! How, well after spending over £700 on parts scanners etc,. I invested £100 in the JLR SSD V16 software. Then my son in law who works for Copart on all JLR models came over, I didn't think it could be sorted after replacing the abs/DSC Module amongst others and every week the codes increased.....just sitting there, I was at my wits end and figured it would end up on eBay.
However Andy (my son in law) opened up the SSD software and started, and it did take 3 hours, and all he changed was the yaw rate sensor (which I had already changed) and he cleared ALL codes and even programmed me a new key.
I had bought the iCarsoft scanner, and very good it tells you the codes but not how to fix them, it leaves you to go through the Jaguar PinPoint procedure, which we did and it pointed to the abs/DSC Module, and it turned out it wasn't..However the SSD sorts all that....BUT & its a big BUT, the software works in the hands of an auto electrician who knows the software inside out, and as Andy said SSD has been superseded by two further software OS, so a lot of guys have no idea how SSD works. I did venture into it when I bought it, but soon realised it was well beyond my pay grade.
So to anybody who is struggling, as I was to the point of being ill, and spending endless cash on parts you think it needs, if your at your wits end, please, please find a good guy who knows SSD inside out and after seeing how it performed at the weekend, it will sort your XK8.
What's needed :_ a laptop running windows 10/ Internet Explorer/SSD software/Mongoose Cable/...... & when you're using it in the car the battery must be charged to over 13.4 volts, I have to have two chargers running and both were hot !!
So wish anybody who was in the same boat as me all the very best, and just hope my experience saves you a lot of money, time and heart ache.

A.T. B. Bob

 

Bob, you said you changed the YAW sensor and no change but he changed it and it solved the problem???

 

Hi,
Yes that right, on the scanner It appeared they both worked, so I put back the original assuming it was ok. Then Andy changed it for the other one I purchased and he could clear the code, just to check he put the original back in and the error code came straight back, so put the newer one in and again he could clear the code, but I just couldn't believe all the codes went. I had sent my DSC/ABS module for testing at £70, and came back no faults, so I assumed they had damaged it in some way as I had more codes, but I felt very embarrassed as obviously there was nothing wrong with the unit. In hindsight, I should of bought the JLR SSD software in the first place left it to my son in law and I would of been around £600 better off, but you live and learn. Ive had the car 8 years and mechanically have had a fair few jobs, but never had any electrical faults.
Looking at all the forums I now believe it could all of started with a low battery, which was 5 years old and although trickle charged I now find it wasn't keeping it above 12 volts, hence drove it in the garage, ok, drove it out 3 months later and 9 error codes, one of which showed battery voltage. Bought a new Bosch battery but by then too late. So just hope by putting this on the forum it might help somebody with similar problems. However as I did say using watching Andy using the software I would of had no idea of going through all the steps to clear the codes.
I can now sleep at nights without the constant jag problems running through your brain.
Take care all...
Bob