Hi all. I'm having several intermittent faults on the X350.
1) I often get the dreaded 'Restricted Perfomance' warning coming on, Cruise Control etc stops working and so on. if I stop, switch off, then start straight back up it's gone. it's also intermittent as to when it decides to come back on.. can go for weeks, sometimes 20 or 30 miles. However, the previous owner was honest enough to tell me he had an EGR problem causing 'Restricted Performance' and had it mapped out!!! .

2) Pretty much the same with the steering.. sometimes it's a tad stiffer than normal, again, switch off and back on and it's great. Checked fluid, topped up a little, but still sometimes a problem

3) I get a feint smell of something burning, a fluid burning smell, but only stood at a junction or traffic lights, pull away and it's fine. Rarely, I get a puff of smoke when stood with the engine running? I'm beginning to suspect I have a Transmission Fluid leak onto the exhausr, maybe from the steering (causing problem 2 above?), but haven't seen any evidence of a leak under the car yet

4) The information clock on the dash with the mileage/messeges. First start up, it's blank, as the car warms it flickers on. Looks like a daft connection, but thought I would add this to the list in case it's a known issue? Lit up or not, this problem doesn't cause a 'Restricted Performance'.

Really hoping someone can say, yes, it's this, that will affect all and is a dead easy fix!!... yeah right lol...
As always, appreciate the vast knowledge on here and hope someone has some idea of what's happening.
Paul

 

I suggest that you have the vehicle scanned and then post the results on here.

 

Thanks for your reply meirion1, I took your advice...
The car was driving OK, except when it went into Restricted Performance. My battery was showing a faily low voltage (11.1v) so I changed it for a new one this morning. Took the car for a drive, and all seemed fine until I tried to put my foot down! The Amber light came on, but of course I couldn't see what was wrong as the information part of the speed clock still doesn't come on with any kind of message! I tried to use the scanner Battery Maintence System (BMS) feature, but it stated the function wasn't supported on my vehicle. For those wondering, the tester I have is an iCarsoft CR Pro.
I managed to limp back home... maximum it would do was 25 MPH and spluttering, there was a constant annoying beeping as soon as I moved, the beeping stopped when the car stopped and started again as soon as I moved? When I got home I turned everything off, plugged the tester in again and switched on, the Amber light went out, started up, still no Amber light and it revved fine again, so seems to have cleared?

I did the tests, and found quite a few odd codes that I was able to fix, lamps out, that sort of fault. However, these ones I don't know what they are, and if I don't know, I don't touch!! So I thought I would throw them out on here...
U1262 - SCP (J1850) Communication Bus Fault
B2162 - Right Side Module Invalid Identification
C1719 - Front Left Center Sensor - Circuit Fault (I have picked up a new sensor today and will fit tomorrow
B2139 - Data Mismatch

Not sure if the above are related in any way, but I did notice someone on the Forum in the past has had the very same 2 faults... but I didn't notice a 'resolved / fixed' message. It turned dark, so didn't try a test drive again to see if the Amber Light and beeping sound had gone. I will do this when it's light again tomorrow.

Any suggestions are always welcome. Not much drives better than our jaguars, but when the electrics go wrong it's so frustrating!!!
Paul

 

I asked ChatGPT (more to test ChatGPT!) This is the (abbreviated) result for U1262, the other codes were beyond it:
The fault code U1262 in a Jaguar vehicle corresponds to a communication error with the SCP (Standard Corporate Protocol) network. This network is used for communication between various modules and systems within the vehicle.

Here are a few steps you can take to diagnose and address the U1262 fault code:

1. Scan for Additional Codes: [Yeah Right]
   
2. Inspect Wiring and Connectors: Communication errors can often be caused by issues with the wiring or connectors. Inspect the wiring harnesses and connectors associated with the modules mentioned in the diagnostic trouble code (DTC). Look for damaged wires, loose connections, or corrosion.
   
3. Check Battery Voltage: Ensure that the vehicle's battery voltage is within the acceptable range. Low voltage can sometimes lead to communication errors. If the battery is old or weak, consider testing or replacing it.
   
4. Inspect Modules and Components:
   
5. Perform Module Reset or Reprogramming:
   
6. Consult Service Information: [Yeah Right]
   

Before I did that (honest!) I guessed it might be a connector problem so worth wiggling or reconnecting them. Unfortunately that's not easy because goodness knows where they all are. I see it said "Check Battery Voltage" just as everyone says here: to me that means charging the battery with a charger just being new isn't good enough.

 

You should be able to see B+ live data with your reader - our cars do not have the battery monitor system. As noted low voltage can cause problems with the bus com and can cause intermittent problems as well. Pending codes coming and going, clearing themselves, indicate intermittent problems.
Since it is affecting REM and Drivers Door modules looking at their module voltages may give a clue. Don't be surprised if the DDM is quite low - that is normal.