Hi everyone, first time posting, so be kind🥴 My 2004 S-type V6 SE Auto is intermittently flashing up code B2736, with the above dash warning. Can anyone advise exactly where the Pedal Travel Sensor is located please. I have been told that this will contribute to an MOT failure. Is replacing this item something which can be tackled by myself?
Regards weltidave 👋

 

Prior to replacing any parts, start by checking available battery voltage. There should be a minimum of 12.6 volts across the battery terminals when checked with a voltmeter. If there is less than 12.6 volts, charge the battery for three to five hours at 2 to 5 amps and retest. If there is still less than 12.6 volts, the battery is suspect and should be replaced prior to attempting any further diagnosis as guessing on a Jaguar can become expensive very fast.

Many of the instrument cluster warnings and random DTCs chased on these forums are the result of a failing or weak battery.

 

+1 on that!

Did you have any other warning messages? It’s common to get parking brake and cruise control messages at the same time. The root cause is often low prestart voltage, as detailed here:

https://www.jaguarforums.com/forum/s...faults-193787/

 

Many thanks have just checked battery voltage, found it to be 12.3 volts. As suggested am charging the battery so will see if that makes a difference
Regards weltidave 👋

 

Hi yes I did have spurious Gearbox fault alarm one time, which cleared and has not reoccurred 🤞👋
Regards weltidave

 

Further checks showing 14.5 volts after charging. Started engine, used multimeter to check voltage available at terminals, found to be 15 volts. DSC unavailable warning on as soon as engine fired up, without moving car. 🤯
Regards weltidave 👋

 

A common failure of the solder points in the ABS module can cause the instrument cluster 'DSC Unavailable' message to appear. Here is a link to the procedure as a PDF:

https://www.dropbox.com/s/6bac9oucci...epair.pdf?dl=0

Another cause is a broken ABS sensor ring on one of the axles. This appears to be common if the vehicle is operated in conditions subjecting it to salt and dampness.

 

One important gotcha we forgot to pass along. Immediately after charging, a battery can show a misleading high voltage due to a phenomenon known as surface charge. 14.5v (at rest) is very high and is almost guaranteed to be that.

With the ignition off, turn on your high beams for about 30 seconds. That bleeds off any surface charge. Then take your voltage reading. This will now give a more accurate indication of battery health and how it will respond under the massive load of the starter.

It’s very normal for prestart voltage to drop with the starter engaged. The important thing is that it not drop too much. We’ve had many instances where the starter seemed to operate at a normal speed, but the voltage dropped just enough for some computer modules to act up. So don’t judge battery condition on how the starter behaves.

 

Hi decided to bite the bullet and invest in a new battery, the original battery was definitely not holding a charge. It was starting the car no problem, but given the thread content I decided to remove one possible cause of the spurious alarms 🤞🤞. Thanks to everyone for their input and support
Regards weltidave 👋

 

Hi everyone I’ve rechecked for fault codes after installing a new uprated battery. The B2736 code still remains. I would welcome any assistance in locating exactly where this sensor is located, and how it can be checked
Regards weltidave 👋

 

Thanks for humoring me and trying the battery.

Wiring diagrams can be found here, near the top of the page:

JagRepair.com - Jaguar Repair Information Resource

I am on a trip and can’t view the diagrams properly, but it appears your suspect “sensor” is actually the on/off switch for the brake lights. The location is listed as at the top of the brake pedal.

Look at the diagrams for the parking brake and rear exterior lighting. The DSC diagram does not show the brake pedal switch, oddly enough. It must get this input from the parking brake module or rear electronic module, communicated via the data bus. I’m not seeing any direct input.

Are your brake lights working properly?

 

https://testing-public.carmd.com/Tsb/Download/71440/350792. Try this

 

Hi brake lights are all functioning properly, thanks for the wiring info
Regards weltidave 👋

 

Ah, that’s spot-on perfect to diagnose this fault. It has the part number if a new sensor is needed, too. Even if you can’t do all the hi-tech stuff with the factory scan equipment, you can skip that part and still do the basic voltage and continuity checks. I’m at a loss to help much further, because at the moment I’m unable to open any large PDF files such as the wiring diagrams or service manual.

From the description in that TSB, it sounds like this mystery sensor is on the power brake booster (under the hood, on the firewall), not on the brake pedal like I was thinking.

If you follow the same link I gave earlier to the wiring diagrams, further down on that page you will also find the service manual. You should be able to find more details there for this mystery sensor.

 

Sorry for delay in responding, been away for weekend. Thanks for all the info, much appreciated. Going to check voltages, and then decide whether to attempt replacement.
Regards weltidave 👋