A strange thing happened. I was stopped in 2006 XKR i a traffic jam and turned the engine off. After about 5 min cars started to move. I tried to start the engine - no power. Black instrument panel. I turned the ignition key about 4 times, before instruments lit up and the car started. DSC system fault came on and is still on. My otherwise very good diagnostic scanner Foxwell cannot turn it off. Creader III scanner shows codes C1446 and C2785. It cannot erase them either. Brake lights and brakes work as before. Since this occurrence I drove about 400 miles without any problems. Any advice? Thanks.

 

C1446 might be failure of one of the brake switch circuits. Your stop lamps work, so check the cruise control. Also check to see if the DSC switch lights up when you push it. The switch could be faulty.
C2785 is DSC sensors out of calibration- I don't have a clue.

 

Hi, Cruise control works. DSC switch red LED does not show anymore. No reaction when pushing a switch. C2785 might be "yaw sensor" fault. But I cannot find that sensor - not in the wiring diagram nor in downloaded manuals.

 

Centre console, apparently. See this thread from Sullair:
https://www.jaguarforums.com/forum/x...1/#post2429259

 

Driving to Georgia. After 338 miles the Cruise control quit - "Cruise control not available", and "check rear lights" warning s came on (while DSC system fault persists). I tested Yaw sensor and it works correctly. A scanner brought a new code - brake switch failure. As I wrote before, brake lights work. Problem has to be somewhere between the brake switch and cruise control system.

 

Those two alternating dashboard messages are the classic signs of a failing brake pedal switch. Replace the two microswitches in your brake pedal switch assembly with more robust ones and you will be good to go. Numerous threads here on the forum covering this subject. Use the search function with "XK8 brake pedal switch repair" as your search phrase and read all about it....

 

More bad news. My scanner shows another ghost problem - "rear left door ajar" (xkr does not have a rear doors) - on the way back I hit some debris and damaged the engine oil cooler. I have nursed the car home on 11 qts of oil. 2122 miles in 3 days with a very good mileage 24.9 miles/gallon

 

How old is your battery? Failing batteries often throw spurious OBDII codes in these vehicles....

 

^^^^^^* this !

….. and is the battery kept on a battery tender when the car is not being driven a few days or
longer ? That can make a big difference in keeping electrical gremlins away.

Z

 

battery is about 1 year old. It keeps a charge for month.

 

Today, I removed the brake switch, tested it re-soldered wires to the printed board (just to be sure) - and still the same problem - DSC system fault, "no cruise control available" and "check rear lights" come on. The scanner gives me the "ghost" warning - driver's side rear door ajar". Could it be a body module partly fried? I am getting a lot of "No Communication" messages from the scanner with - ABS module, ACC module, Instrument Pack. When testing BPM module I get "loading data, wait" and scanner does not finish scanning (i waited 10mins).
All codes collected with two different scanners : P1571 (brake switch), P1000,P1638, B1260, B1582, C1446, C2785, U1901, U2523...
Just want to remind you how it all started: I was stopped in a traffic jam and turned the engine off. After about 5 min cars started to move. I tried to start the engine - no power. Black instrument panel. I turned the ignition key about 4 times, before instruments lit up and the car started. DSC system fault came on and is still on I lost cruise control two weeks later.
I am getting desperate and almost ready to sell this cat...

 

This might sound ridiculous, but does the ground strap (to the battery) get hot ? I had a similar problem - dead power all of a sudden when going to start. Called wife for a jump, went to jump start the car and power returned before I got the cables hooked up. I replaced the braided ground strap for a solid one and no problems since. Cheap fix. Another thing, when my battery gets low the "DSC System Fault" is the first sign.

 

Thanks,
i looked at it- battery 12.74 V, charging 14.48 V, all cables tight.

 

still no DSC system fault solution updateToday, I removed the brake switch, tested it re-soldered wires to the printed board (just to be sure) - and still the same problem - DSC system fault, "no cruise control available" and "check rear lights" come on. The scanner gives me the "ghost" warning - driver's side rear door ajar". Could it be a body module partly fried? I am getting a lot of "No Communication" messages from the scanner with - ABS module, ACC module, Instrument Pack. When testing BPM module I get "loading data, wait" and scanner does not finish scanning (i waited 10mins). DSC switch in console does not lit up when pushed. Is there any method to test the CAN bus?
All codes collected with two different scanners : P1571 (brake switch), P1000,P1638, B1260, B1582, C1446, C2785, U1901, U2523...

Just want to remind you how it all started: I was stopped in a traffic jam and turned the engine off. After about 5 min cars started to move. I tried to start the engine - no power. Black instrument panel. I turned the ignition key about 4 times, before instruments lit up and the car started. DSC system fault came on and is still on I lost cruise control two weeks later.
I am getting desperate and almost ready to sell this cat...

I borrowed a friend's 2002xkr and I am allowed to swap different modules between those two cars. I do not want to waste a lot of time unnecessarily. Any advice how I should proceed most effectivley?

 

So Dneu I tried to solder new circuits to my failed brake switch and it didn't work. Probably because I soldered like sh#t but still thought I would share. A new brake switch fixed it. I do find it odd that yours started malfunctioning after turning the car off and on so there is probably more to it but I hope it is just a brake switch for you.

 

Sorry, but you cannot reliably test these switches, they will measure/read OK on a meter etc. but are still faulty.
They are cheap and easy, do youself a favour and change them for peace of mind

 

Why not, I tested both switches with Ohmeter - and brake lights work and react to the pedal. (used switches sell for 122 dollars).

 

Update - no progress - still DSC system fault/check rear lights persists. I updated Foxwell 624 Elite scanner. there is a list of a new codes:
P1582 (not erasable)
C2785
C1446
Instrument pack codes
U1261
U1260
U1147
U1900
U2521
U2522
U2523
BPM _ no communication
ABS - no communication