Crazy Electrical Faults! RESOLVED
 

All last Summer and Fall car running fine. Left sitting for a couple of weeks mid-November before putting it to bed for the Winter. On starting to put into garage, all gauges and lights went crazy. All warning lights on, messages as follows: "Traction Control Failure", "Transmission Failure", "Battery not Charging". Check engine light, ABS light, Airbag Warning Light, Amber and Red center lights - ALL on. Battery indicator gauge right over to max charge. PLUS a dim glow from the Sport Mode switch LED. Car in Limp Mode.

I thought Huh! Battery low after standing for a couple of weeks. I'll put it to bed and sort out in the Spring. Spring is here! Bought new battery and started car - instant start. All same problems. Turn off and then back on - allow car to go through its pre-flight checks - all lights go off except check engine and airbag. Start car and all faults return as described in para 1.

Have checked and cleaned major ground points to no avail. Once car is warm however, faults do not appear until you get above 1000 rpm - car revs to 4000 rpm so not being limited to 3000 as happens in Limp Mode. Just occasionally, maybe 1 in 12 starts, the faults don't appear apart from Check engine. Have tried to read codes with my iCarSoft reader, but says Comms error can't read codes. Have order IDS software but wont be here for a couple of weeks.

Has anyone experienced anything like this - any suggestions gratefully accepted.

Car is 1997 XK8, 4.0 Convertible.

Thanks for any suggestions.

Quite possibly the alternator/regulator, particularly if the voltmeter reading goes high. I had very similar, but not identical symptoms. Be careful as overvoltage may cause damage. Check these two posts. Note code P1793 may be thrown:

https://www.jaguarforums.com/forum/x...arging-184070/

https://www.jaguarforums.com/forum/x...esolved-93290/

which icarsoft reader do you have.?

on my icarsoft LR-1, when you first turn it on you are given several modes to choose from. Using the diagnostic mode, mine connects fine every time (on an '02 XKR). But if you try to use the OBD-II mode, it never connects.

hope this helps .....

Z

I still think battery. No battery you can borrow. Charge up and fit just to try?

Thanks for the Replies - especially Michael - those two posts you referenced do seem to have symptoms very similar to mine. I'll check the Alternator but will hold off buying a new one until I can get to the codes.

Thanks Z, I have an iCarsoft 930 scanner. Does diagnostic mode allow you to get to the ODB II codes? If so, how. Have long since lost the little book that came with the scanner.

Thanks Frank - I agree - but the battery is a brand new 950 CA MAXX, so this seems unlikely - though a duff new battery is possible. It was my first thought (as 90% of peculiar electrical faults are due to low voltage!). Will check Voltage to be sure.

Will keep you all informed.

You can try a quick check by removing the serpentine belt and running the motor (briefly!) to see if electronic sanity returns.

I don't know the 930's operation, but if it's similar to the LR-1, then yes. From the opening screen I first chose diagnostic, then the sequence goes like this:

LR or Jaguar,
year of manufacture,
model,
automatic or manual scan (I always choose automatic, when I try the manual scan the data doesn't show as available)

then a choice of modules is given, like engine, transmission, ABS, etc

for example, if I choose engine, a display of all engine data is provided and you have to scroll down to whatever you are looking for. Often something like fuel trims is shown as not available, but if you keep scrolling down, it comes up again, and the second time it displays the data.

weird . But I have a tenuous relationship with all things electronic and computer related. So for me even a round-a-bout and limited success is a win.

Z

Hi All

I am sorry for the long delay in completing this thread. It was indeed the alternator - replaced with a used one from Ebay and normality was restored. I have a cracker of a problem now which I will start a new thread for - not for the faint hearted! Many thanks to all who offered advice.