My 2006 XK8 with just 33,800 miles started showing an DSC System Fault message. It shows up intermittently. I took the car to a reputable service shop and they told me that after performing a diagnostic test they need to replace the “Brake Pedal Travel Sensor.” They said when the sensor is replaced they will run another diagnostic test to see if that resolves the issue or if it is something else such as a ABS brake module. The cost quote they gave me to replace the brake travel sensor seems quite expensive to me especially if the part doesn’t need to be replaced in the first place. Is there a way to test the sensor instead of just replacing with a new part? Any tips or suggestions? Thank you, Scott

 

From memory (which is not what it used to be) that fault was my first sign of the well known ABS module solder failure fault. My car is 2000 MY, not sure if that fault carried through to 2006.

 

Probably not. My ‘06 STR has the single connector ABS and the one that fails has two??? Anyways I know mine has the connector that goes to the unitbthat doesnt fail

 

If that message shows during startup, it is a sure sign of an aging battery in need of replacement.

If that message shows while driving, it is likely the wiring to the ABS sensors, most likely on the front. You need to have a proper Jaguar/Land Rover code reader to tell you which one. There is also an off chance it is a sensor, but it is less frequent. Some believe in a periodic cleaning of these sensors.

As a general statement, you are right not to go on a replacement spree without supporting evidence from a proper code reader. And your shop is undeserving of "reputable" if they do not start with a proper reading of fault codes.

There is a brake switch (not a travel sensor) that frequently fails, but the (confusing) error message urges you to check the rear bulbs. That switch (a pair of switches actually) is not super cheap and somewhat of a bear to replace (working in an awkward position in the foot well). It does not seem like the culprit from what you are describing.

Best of luck, keep us posted.

 

I agree with 1) cleaning the wheel speed sensors and 2) checking the wheel speed sensor wiring harnesses (look for splits and cracks in the insulation area where they plug into the sensor)....

Do those tasks first before you opt to spend any money on new parts. Cleaning the sensors at every oil change and repairing the split wiring harness insulation with RTV silicone has kept any ABS or DSC fault messages from appearing on my wife's 2006 XK8's dashboard for more than seven years now....

 

Agree with above. You should find a place that can read the chassis codes or buy a tool for yourself that will read them. The ABS module is usually not a problem with the later models, and the brake switch will usually show the "cruise control not available" message on the instrument panel. This message is the first thing to show up when the battery is weak.

 

Thank you for the tips. I’m trying to do my best to make the right decisions and not waste money. I was given a fault code of B2736. I’m still researching to understand what it means. Thank you again, Scott

 

Thank you for your comments. I’m hopeful that the ABS module is not the case.

 

Thank you for the tips on cleaning the sensors checking the wiring harness for cracks. I’ll get on looking at the harness ASAP.

 

Thank you for your comments. I plan on buying a code reader. Given what I have experienced so far I think it will be a wise investment.

 

Now that you have posted the code, it looks like this is a problem that comes up once in a while. The travel sensor (part#C2C39935) seems to be located on the brake booster. As usual, prices vary from cheap-enough-to-throw-at-the-problem to more than that. It looks pretty accessible, so I would start with a visual inspection and a cleanup of the plug.

 

Thank you, Scott

 

Agree with fmertz. B2736 is a brake position travel sensor circuit issue a discussed on the thread below. Seems to be about $130 or so around these parts. Helpful advice on the thread below reported from random mechanic, paraphrasing "replacing it just gets rid of the warning".

Of course, I personally would fix it since I hate the warnings...

https://www.jaguarforums.com/forum/x...warning-39970/

 

I had the same problem on my 2001 XK8 and it was only solved when I re soldered the connectors in the ABS module

 

My similar problems were linked to the wires to front ABS sensors being a little too short. They would tug on the sensors when the steering wheel was at full throw and cause a disconnect. All I did as cut the tie wraps on the upper control arms and reposition the rubber mounts a little closer to the wheels with new tie wraps. I also bent the pins on the sensors ever so slightly to improve contact and used a dielectric grease to insulate the connections from the environment. Never had another warning / glitch afterward (tens of thousands of miles).

 

Likely the important part here is the code, B2736 which is for the brake travel position sensor circuit. Many things can make the DSC warning illuminate.

 

My 2003 XK8 (JRG, cream interior) bought new from dealer's showroom has only 4,300 miles to date (2020) dry miles only and is garaged. There are two comments that can be made on this topic, not necessarily solutions but observations based on my experience.

1. The original battery lasted for sixteen years (on smart charger./maintainer) and was only changed when the car began stopping at random on the road. Restart was instant every time and there was no sign of battery weakness. Local dealer was understandably not particularly suggestive of options without attaching their computer and very expensive anyway without certainty of finding the problem but a definite certainty of repeated invoices.. A review of this forum left me very perplexed at the number of possible causes but out of all this I derived what turned out to be a "cheap" and effective solution. I changed the battery on the basis that the original was very old anyway and that, on an age basis, the life left in it would be limited. That solved the problem, no more stoppages. When there was plenty of starting power in the old battery why should it have been causing random engine failure? Marginally lower voltage to the sensitive sensory circuits perhaps? I don't know.

2. The relevance to DSC warning comes next but is there any relevance?
I had been seeing and ignoring the frequent and random DSC warning for years before the above engine failure problem arose. After changing the battery earlier this year the warning disappeared but has reappeared a couple of times since. It goes away next time the engine is started.
I'll keep in mind the useful suggestions re. ABS connections and others. Thank you everyone.

Moderator please split this into two threads if desired

I'll leave this with you all for thought. No response expected.
Kumzar..

 

Very low miles. I guess this is a comment on how often it rains...

To avoid dealer invoices, you might want to invest in a jag-specific code reader. It might be difficult to discern among the numerous causes of a DSC warning without reading the codes in the car. Here, for example, the code suggests a particular circuit that is likely bad. Other issues might involve the other sensors in the system, the ABS module itself....

 

Thank you crb. The Jaguar code reader is an excellent suggestion. Yes, shrewdly observed, alas it does rain rather a lot here. (Maritime temperate on the wrong side of the Atlantic under the jet stream).

 

Thank you, I was planning on investing in a Jaguar code reader and some manuals so I can understand the parts and where the are located in the car.