During the three years that I’ve had my 2000 XKR, the engine would occasionally not crank when I turned the key to “Start”. After one or two additional attempts, however, the starter would always crank and the engine would come to life. I didn’t give it much thought until a week ago when it wouldn’t crank at all. After about twenty tries, it finally started and I was able to get the car home. Since then, I haven’t been able to start it at all. Everything else appears normal - the dash lights show their usual information, the radio comes on, etc. - except the starter doesn’t energize. The battery is about two years old and is kept on a Ctek maintainer whenever the car is in the garage.

AutoEnginuity on my laptop came up with the following two codes: P1260 (Theft detected, vehicle immobilized) and U1135 SCP(1850) (Invalid or missing data for ignition switch/starter). After I cleared the codes and re-ran the test, only the U1135 code remained.

I tried what would be the easiest and least expensive repair, which was to replace the Key Transponder Coil (LJA2668AB), but that didn’t fix the problem. So now I’m hoping for suggestions where to go next. I suspect the problem may be in the ignition/starter switch itself, which I’m hoping won’t be the case. Replacing it may be beyond my ability, and what if I do replace it and it turns out not to be the problem?

I think I need help!

Vince

 

Do you have more than one key? How about even the valet key? It looks like somehow the system is not able to confirm the crypto chip in the key handle is producing the right result.

Have you tried the "hard reset"?

 

Yes, I have two ignition keys that show the same symptom. Neither will start the car.

BTW, I also have two remote transponders that are operating normally: I can lock and unlock the doors with both remotes. That tells me that the Security Locking Module is working at least partially.

Vince

 

Oh, and yes, I also tried a hard reset. No joy.

 

Separately from the SLM, there is a key transponder control module. Might be worth locating both modules and having a look for bad connections or any damage. Never been too sure where the actual key code is stored...

 

Good idea. In researching the problem on the Forum I found that the key transponder control module is hidden way behind the fascia in an almost inaccessible spot. I'll try the SLM connections first.

Thanks for your suggestions.

Vince

 

There is an exciter coil at the key in the steering column. This has been known to fail and if it does, you can get the code you are getting. The coil is an antenna that communicates to the chip in the key to identify the key as the right one. There are other potential problems in the starting sequence as well. Be sure to reset the inertia switch in the drivers side foot well behind the panel first, as this is the simplest task. If the exciter coil is ok, the rest of the sequence is key transponder module, body processor module, starter relay, solenoid and starter.

 

Oops, forgot to mention the not-in-park microswitch in the park detent of the shifter assembly. If this is not working right, the transmission might think the car is in gear and won't let it start.

 

Fmertz, interesting thing happened. I tried another hard reset, and it started - once! In order to get it to start again, I had to do another hard reset. At least I can get the car to my local Indie, if need be. I'll try cleaning those connectors next to see if I can get the car to start more than once in a row.

Oldmots, I've already replaced the Exciter Coil. I'll try you other suggestions next.

Thank you both, Gentlemen,

Vince

 

If it will only start once after a reset, it stands to reason that while running, something critical is losing its reset adaptation. This could mean a software or module failure. At least you can rule out mechanical failures like solenoid or starter. You might have a failing body processor or need to go to the dealer for a reflash to the ECU.

 

I agree. It feels like something electronic rather than mechanical. I'll continue on the problem tomorrow and if I can't see any progress I'll take it to some professionals.

Thank you for your help!

Vince

 

Well, I checked everything that I could within my limitations, so I did another hard reset, started the engine and drove the car to my local Indie (35 miles away). I'm sure he will will solve the problem and when he does, I'll report back with his findings.

Thanks to everyone who gave excellent suggestions. What a great forum this is!

Vince

 

Just to update the situation: Fmertz was right - the Key Transponder Module was at fault.
I took the car to my local indie who verified the problem was in the Key Transponder Module. He brought the car to a nearby Jaguar dealer who reprogrammed the module to the car. The car now starts reliably.
Many thanks to all who jumped in to help. This is truly a great forum!
Vince