Hi All
This time the problem is with my 1999 XK8.
I stupidly left the key in the ignition and the door slightly open while working on it, then forgot to take the key out and close it up. It was left for several hours like this and when I came back to it the battery was flat.
Charged the battery for a few hours and all looks ok.
Keyfob works to lock and unlock.
When I turn to position 3 there is no crank., nothing at all.
If I lock the driver's door with the key then open it I get the usual beeping telling me the alarm is about to sound. At that point I would normally put the key in the ignition and turn to 1 to stop the alarm sounding.
Now this does not happen. It does not recognise the key at all and the alarm goes off. I do not have another key to test with.

Is this a fault of the Key Transponder Module? I have seen a thread on here that suggests so. Why would that fail after a flat battery?
Could it be the key transponder coil in the ignition barrel?
Reading the electrical diagrams and the workshop manual - In my view something is telling the system that the key is not readable, so there is no security acknowledge signal therefore no OK to start signal.
I would have thought the key can't be corrupted, but something has failed and stopping it being read.
Your thoughts and input are appreciated.
Thanks

 

Let me be the first to say make sure your battery is good - it sounds like it's dead and you need a new one.

Fix that first before suspecting the mysterious black boxes in the car.

 

^^ This....

 

The battery is 6 months old Yuasa. Not sure why it would have failed other than through being drained. It has been re-charged and sitting at 13+V.
The AA came out and tried a starter on it, no luck.
Diags show immobilised due to possible theft attempt.

Thanks

 

If you are absolutely sure the battery is good, then the next thing to try is a hard reset - disconnect both battery cables and hold them together for a few seconds to reset the modules, before trying again. Does the shifter come out of Park with your foot on the brake pedal? Have you tried starting in Neutral? Also make sure you have checked all the fuses are good.

As you only have one key, the next step is to try programming another key to the car, or reprogramming your existing key, which you need IDS for. Plenty of information on the forum about Immobiliser Setup.

 

Any battery can fail at any time....

 

Hard reset done.
It does come out of park.
Tried starting in neutral.
Fuses seem to be good.

What seems important to me is the diags say immobilised. Reset the fault and as soon as you try to start again it comes back.
I guess I have to get a new key cut.

Can the transponder coil fail? burn out if the ley is left in too long?

Mystery.

 

What were you working on? Anything "electric"?

Check the electric diagram and find out what data bus (SCP or ISO9141) the key transponder module is on. If you have a JLR code reader, try and "interrogate" any other module on that bus to see if you get anything. Maybe the data bus is somehow not operational...

Maybe recharging the battery somehow fried something. Use the code reader and check if you can reach/read data from all the modules, one by one. Also check ALL the fuses.

If you did any work in the vicinity of the instrument cluster, double check the connections are what they need to be. The IC acts as a bridge between the various bus technologies involved in this car (CAR, SCP and ISO9141). I know there are TSBs about bad solder joints on the IC board, but I believe the symptoms end up being about the CAN bus.

Once you know the data bus is operational, another cheap option is to procure one or more megamos id 13 cypto chips off of eBay and try and "program" them to the car as if they were keys. See if that procedure gets you anywhere.

Best of luck, keep us posted.

 

If there is no wiring issues caused while youre working on the vehicle, and the battery is 100% good. Than all you have to do is run the Immobilizer or key programming, what tools do you have? What scanner are you using ?

 

Thanks for your reply.

I was actually working on another car and was pumping up a tyre so used the 12v cigarette lighter to power a small inflator for a few mins. Just left the key in afterwards.
So in theory nothing on the XK8 should be disturbed. This only happened since the flat battery.
Really odd.

 

If the electrical guide is being truthful, the key transponder is on the Serial Data Link (ISO 9141) ““Serial & Encoded Data” bus, so a code reader such as the Torque app and OBD dongle would immediately show if that bus is working from looking at the live data, such as engine temperature etc.

For what it's worth, I would think the likeliest explanation is the dead battery combined with a jump start attempt corrupted some memory and the OP needs to do an immobiliser setup again on his existing key, but he needs IDS for that. For the OP: there is no point in getting your existing key copied - a new chip still needs to be programmed to the car, a copied chip will still not work just like the original.

And as a note for everyone else - this is just one reason why having a second working key is essential, hindsight is of course 100% right all the time.

 

you will have a P1260 stored. these forget keys from time to time usually when the car sits for a long long time, but they never lose ECM to KTM sync. a good key but unsynced KTM results in a crank no start.

you can put keys back in with aftermarket tools, launch will definitely do it i forgot about autel.

 

Got a P1260 stored.
Torque is showing live data such as throttle position.
Fuse 3 a 5A fuse blows when ignition moved to position 2.

Still investigating.

 

Fuse replaced, checked starter relay, that is ok. Fuse no longer blowing.
Still P1260 no crank..
Confused.........

 

Which F3 - Engine Compartment fusebox?


The P1260 will keep throwing until the car is happy with the key.* First move is to reintroduce the car to it as noted above.

*P1260 from DTC list:

 

Thanks for that.
I have called a "specialist" and see what he can do.
I do have a spare KTM from the same year, but apparently they are all the same.
If you bypass the starter relay it will crank. Handy to know, but obviously everything else on the engine is still disabled.
See what the specialist says when he arrives.
Thanks

 

you just need to program a key

 

Specialist could not help. Launch, Autel and SmartPro all not working. SmartPro only shows an error.
He is going to reload SDD on his laptop, but searching the forums it suggests that SDD is too new and I need IDS v118.

Where can I get this?
I have looked here but they are all new again.
https://www.jaguarforum.com/threads/...nstall.108460/
@motorcarman do you have access to the older IDS versions?

Any advice welcome, still immobilised.
Thanks

 

SDD 165 will do it no problem. does he even have comms with the KTM?

 

I have downloaded SDD 125, thinking older was better for a 1999 car. Is it best to go for SDD 165 then?

He was not getting comms to anything, it was just reporting an error. Probably the same P1260 I was getting from what I could tell.
He mentioned it could be an SCP problem. I have read that the security can block access to some systems.