Has anybody yet found a difinitive fix for the 'ASC Not Available, Trac not available, limp mode' problem. I have tried all of the fixes mentioned in all of the posts I can find but it still happens every time I go out. I can only go a few miles before it happens. Sometimes it happens four or five times in one short trip and it is highly dangerous and embarrassing. Imagine losing all power in the outside lane of a motorway at 70 mph. Ridiculous. The previous owner had spent loads trying to solve it, and then he sold it to me. He saw me coming, as they say. I have done all the throttle body fixes, the MAF sensor, the cleaning of electrical connectors and earth wires. Even a brand new battery and just this week I changed the whole instrument panel after the odometer faded away. It's driving me nuts, but not where I want to go. I am seriously close to stripping it for spares as I cannot get to the root of it. I have had the fault codes looked at and cleared as well, by the way. Again, no luck. Any help would be fantastic please, as I am at my wits end now.

 

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Panzoom, I'm assuming you cleaned all four wheel speed sensors? That's one of the easiest first "fixes".

Then next is the ABS module repair/rebuild.


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If you have the codes read by a shop with Jag specific software and print the codes here, we can probably be of greater help.

 

I'd read all the codes from all the modules (more than once). I'd do it before, during and after it went into limp mode.

Getting someone like an indy or dealer to do it is not likely to be much help given its history (unless they are in the car with you but that's liable to be costly, so DIY).

 

Unless he has a reader for chassis codes, he's not going to get enough information. If it goes into limp mode the codes should be stored.

 

For me, the fix is to get one!!

 

When you say you've done all the Throttle Body fixes - what fixes have you done? And as mentioned, codes are really the big factor, to see what's tripping it. In my case, it's tripping and the only solution is a Throttle Body rebuild to get everything up to snuff. Too many could-be directions to look towards, depending on the codes and what might still be left undone yet.

 

Had that issue on my 2000 XJ8 and I simply replaced the ABS module with a rebuilt one.

 

Thankyou for all your replies. I will start with cleaning the sensors but have already fallen at the first post as the bolt holding the sensor on my first chosen wheel needs drilling out as it is jammed tight. Thanks again everybody !

 

ABS/TRAC/STAB/ Faults are caused by the following
1. A weak or dead battery - replaced
2. ABS PUMP MODULE fault code C1095 - FIX repair of module pump pickup pins
3. Wheel speed sensors/ring - prior to removal check inboard behind the hub and look to see if there are any debris between the ring and sensors on all 4 wheels.

When removing the sensors, flood with a penetrating oil and lightly tap the bolt heads with a small hammer, carrying this out after a drive with some residual heat in the hub assembly can make it a little easier. They're threadloc'd.

 

Thankyou very much Sean B. Very informative. Thankyou for taking time to explain this in detail. Much appreciated !

 

Couldn't remove the sensors but did spray contact cleaner between them and cog teeth. Also rubbed down cog teeth with small wire brush and finished with some wheel cleaner and a rub down with a cloth. Did both front wheels. Two faultless journeys since where it would have gone into limp mode repeatedly previously.

 

Checking connection between wheel sensor and abs module. Very easy!
LJA2226AA Jaguar X300 XJ6 XJ12 XJR ABS Speed Sensor
Maybe put 4 of these on order, or maybe just two even.
Mine rusted away into the wheel hub, needed drilling out and I also re threaded the retaining bolt. Wasn't hard in truth.
Make sure you don't buy the older looking sensors that are available on eBay as these seem to have a lower resistance and don't remedy the fault code. 600 vs 1100 in my case.
Never had a limp home fault from this though. The actual continuity test is quite easy to do too