Before you say it, I put in a new battery on the car two weeks ago. This has been happening since before the battery. Besides, the windows are maintaining their position, so no Azheimer's that would point to the battery.

Every now and then, I get an unexpected fault. Before today, it would be the suspension fault warning with the amber light, this one would usually happen upon starting up the engine. Turn off the engine, wait a few seconds, start it up again, and now it's gone. Today, I got a different warning: transmission fault. This one happened after I had been driving for about an hour. Did the same thing. I pulled over, turned off the engine, waited less than two seconds, started the car again and the fault message was gone. I know this is electrical because the car has no other symptoms. Transmission shifts perfectly, the suspension rides perfectly. S button, traction control, and cruise control work as designed. Btw, does the S button do more than change shift points on R cars?

Checking the OBDII reveals no codes logged. Other miscellaneous issues include: no windshield washer (I can't even hear the pump whirring), and the side view mirrors don't adjust left to right, but they have no problem adjusting up and down.


Any ideas? Is this the Ghost of Lucas?

 

Since you just replaced the battery I would next check and clean all ground connections, then unplug, clean and replug any control module related to the faults you are seeing. Then see how the car responds.

 

Is there a wiring diagram and a map of where these modules are? Sadly, among all the things I recovered from my dad's belongings, the Jag's manual was not one of them.

 

The manual is the JTIS21 that you download from the Sticky. Wiring diagrams are also at jagrepair.com.

Sport button stiffens shocks and uses 1st gear from stop. Otherwise you start in 2nd.

 

Page 22 of the attached XK8 Electrical Guide shows where all the modules are located.

XK8 Electrical Guide - 2001MY.pdf

 

This sounds like a mixture of:

1. Permanent faults
a) screen washer (probably failed pump)
b) door mirror lateral adjustment (driver's door switchpack, door harness or door control module)

2. Random faults
a) suspension fault warning with the amber light
b) transmission fault

Weird electrical faults like this point to battery. You've replaced the battery so there's only the remotest chance (but not unknown) that it's faulty.

Eliminating the battery then suggests there could be a problem with the battery leads. Check the leads and connections to the High Power Protection Module:



These are known to become loose or break up at the terminals. A connection problem like this allows normal operation of elecrical equipment but shows odd problems when there's a high drain on the battery during starting.

As for the S(port) button, it apparently changes the shift points but I've always thought it does little more than change driver perception!

Regarding Lucas:



Permanently laid to rest in 1996!

Graham

 

Alright, I'll check all of that and get back to you, probably after my microbiology test on Friday.

 

If weird unexplainable electrical things are happening - you might just have a ground issue.

 

Last week I got my 2004 XK8 up from its winter nap, and went for a short drive, all was well. The car was on a battery tender for the last 5 months and it was a new battery last year. I went out again a few days later and my DSC, and ABS no cruise messages lit up the dash like a Christmas tree. Of course it must be battery fingers crossed. I drove home and checked the water levels in the battery, I could see the tops of every cell. I got some distilled water filled the cells and now all is right with the world again. So even thought it is a new battery I think with it being on the tender all winter it must have cooked a little fluid off.

 

You see, here's the thing, I don't get the Christmas tree, I only get Suspension Fault or Transmission Fault, never both at the same time, and it is infrequent. Once every week and a half.

 

You will eventually need to get a Jaguar/Land Rover-capable scan tool for this. There is likely very specific codes telling you precisely what each control module is unhappy with, something beyond what a standard OBDII tool can provide. You can get a handheld tool (check eBay for Foxwell and others) or the factory software/USB cable for a laptop (British Diagnostics). None of these break the bank, really, and handily pay for themselves over time.

 

It might be worth disconnecting and squeezing the wire crimps on the battery terminals with a vise or a pair of large pliers. These crimps have been known to oxidize and cause intermittent problems, esp. on the 2003 and later models.

 

This is how I tested my grounds on my 99 XK8

Link JagRepair.com - Jaguar Repair Information Resource

This is a oneline with grounding connections for your car.

Link For 2000 http://jagrepair.com/images/AutoRepa.../jagxk2000.pdf

Link For 2004 http://jagrepair.com/images/AutoRepa.../jagxk2003.pdf

What battery did you get for your car and did you have your charging system checked? I would do that first before taking any other action.