XK8 - ASC and Trac Control Failure - Scanner shows Nil?

[fast cars]

I only have a cheapo Autel scanner from eBay (£20) has been great in giving fault codes and resting etc etc, but this time my XK8 from the moment I pull away shows ASC and Trac failure, scanner does not show any error codes? Can anyone advise on what I should look for?

Thanks

[Fat Albert]

My immediate thought is one of the ABS sensors or the wiring betwixt unit and wheel.
I had similar and used the guide on Jagrepair.com to determine which wheel was at fault but it turned out that it needed a whole new ABS wiring harness (£120)to cure it

[fast cars]

thanks for the info I will check it out . cheers

[gamefreaks]

The basic OBDII scanners can only read the main ECU. Stuff like airbag lights and ABS codes are stored in a different ECU. (Body Processor Module IIRC). The best you'll get out of a basic scanner is a generic 'Fault in another module' type code.

[fast cars]

Hi thanks for the info. Cheers

[jas xjr]

i had a battery that was on the way out , dash was showing those same faults

[SV8Predator]

fast cars said:

from the moment I pull away shows ASC and Trac failure,

jas xjr said:

i had a battery that was on the way out , dash was showing those same faults

Nope.

Your dash showed up these faults as you turned the key and the engine started up. Then the fault display went away.

That is not what the OP is describing.

[EKdave]

I have had this same issue in my xj8. Easiest and cheapest option is to remove each wheel and take off and clean each abs sensor, maybe use some electrical cleaner inside the plugs as well. The sensor is held in by 1 bolt and might be a little rusty but a bit of spray should see it ease off.

[jas xjr]

SV8Predator said:

Nope.

Your dash showed up these faults as you turned the key and the engine started up. Then the fault display went away.

That is not what the OP is describing.

sorry , i hate to disagree , but a weak battery will show these faults and not only on our jaguars . obviously if the lights went away as i drove off there would not be a problem. it woukd do that every time i started the car .

to the OP charge the battery up if you can , it will not do any harm

[edward1]

Had this similar problem on my xkr. It started as an intermittent fault then became that every time I set off I got the failure message. I had a new battery as I knew it was weak when I first got the car due to lack of use by previous owner, but it didn't solve the problem.

The garage said their fault reader indicated the leads to the front 2 sensors. I unclipped the electrical connector form the abs sensor, took the sensors off, cleaned with electrical contact cleaner, sprayed the electrical connector aswell. Re-assembled and not had a problem since. I didn't even need to take the wheels off, ran the fronts up a ramp and accesses from underneath, took about 15mins in total.

[fast cars]

Thank you very much, I think cleaning the connectors has to be the first port of call!

[andyps]

I have heard that a poor battery can cause this problem so worth checking that.

Also, my XK8 had this issue occasionally and one of the rear wheel bearings had too much play in it, since that was fixed I haven't had the warning again.

[jimattfield]

edward1 said:

Had this similar problem on my xkr. It started as an intermittent fault then became that every time I set off I got the failure message. I had a new battery as I knew it was weak when I first got the car due to lack of use by previous owner, but it didn't solve the problem.

The garage said their fault reader indicated the leads to the front 2 sensors. I unclipped the electrical connector form the abs sensor, took the sensors off, cleaned with electrical contact cleaner, sprayed the electrical connector aswell. Re-assembled and not had a problem since. I didn't even need to take the wheels off, ran the fronts up a ramp and accesses from underneath, took about 15mins in total.

+1 - within yards of setting off the same messages especially if I turned the wheel hard right to navigate out of a car park or hit a bump or pothole. Removed front wheels (no ramp) then unplugged and removed sensors, cleaned them and applied switch cleaner to sensor and cable connections and job done. No messages for many months since I did it. I have no doubt that my local stealer would have charged me handsomely for a replacement loom and labour and as a new loom of course it would have worked as the contacts would have been wiped clean. Don't take any other advice, do this first.

Jim

[fast cars]

In the end after a clean the error still appeared on the dash, so off to XJ Motors in Chertsey, found harness on osf wheel to have perished internally so now replaced at £80 cost for new part. XJ Motors also resolved a very intermittent fault with rough idling - 1 coil pack replaced with a spark plug and now runs like a dream

[Fat Albert]

Interesting that it is the same harness as the one that went on mine...and that yours was £50 cheaper!!!

I will take a closer look at Nene Jags pricing and perhaps try somewhere else next time....