Dreaded P1260 Fault code
 

Hi Folks,
So I hope all you UK owners had a sunny extended bank holiday weekend, my car is off the road dead as dead as can be!

My latest nightmare;-
So I was working on my hydraulic ram above your head, lowering the roof looking for the leak. I started the car half way through the procedure to make sure I had not flatterned the battery, the rear window sensor was un plugged as was the rest of the overhead functions apart from the roof latch. All good car ran, but when I had finished, the car was dead no starter motor? Everything worked dash lights up as normal all the clicks and whirs under the bonnet apart from turn the key interior lights switch off and it's like a dead starter motor, nothing!
So I started the fault finding, as mine is RHD, you can't get near the starter motor not even the cables to test the solenoid with out removing the steering rack and really it can't surely be a coincidence that the starter motor has just gone on me really?

1. Tested all the relays to do with ignition and starter all working, tested by replacing the horn relay as virtually all are the same 40A type.
2. Checked all the fuses, all good.
3. Checked the gear shift makes the usual sound and clicks, tried it in Neutral, nothing.
4. Even checked the inertia cut off in case I knocked that although that is fuel cut off, the hydraulic pipes run by the fuse box on the LHS.
5. Got my laptop out, got a P1260 fault, which is stolen mode don't let the car start, so either the key chip is not talking to via the transponder to the ECU or ECU is faulty, had keys checked all three keys read with their ID48 chip so keys ok, but none now work in the ignition to start the darn thing, although the remote fobs all functions as normal, locking / unlocking the car etc.
6. The Starter relay seems to have 3 positives, that can't be right, not sure if it's actually getting a signal from the ECU? Does anyone know what the 4 pins are supposed to read with a volt meter on ignition position or on turn of the key, I am pretty automotive handy can do virtually rebuild everything on these cars, but am no auto electrician.

Conclusion;-
If there are any ECU Doctors are out there can you give me a clue, my next option is to send off the ECU for testing is all I can think of, if anything to eliminate that. You can't even get a replacement second hand ECU off Ebay as they are coded to the car, so maybe it has to be tested and repaired? From what people tell me the ECU in our cars are pretty solid and don't usually get faults, or maybe I have missed something else here with the security system? I was so careful doing that job I am certain I have not dislodged anything?
Anyway Help required ASAP, this one is killing me!

I'd put money on a dead battery. Almost all strange/unexpected behaviour on these cars is due to low battery voltage.

The usual fix for this is to clear the code, cycle the key 2 times and start the engine. This is a theft detection code and this procedure will reset the ecm.

Brand new battery first thing I did.

Cleared the code, but it comes back, what does cycle the key 2 times mean please? Sounds interesting and worth a try.

This thread has good info, including tests, etc.

stolen-car-93319

Dreaded P1260 Fault code
 

Well I have proper screwed the car now, I power probed the starter solenoid, got the solenoid to function, then not paying attention shoved the power probe straight back to the ECU by mistake,, NO!!!!! I must of fried the ECU as it no longer talks to my laptop and the odd meter tells me faulty everything and 'wrong equipment fitted', so not only have I got a broken starter motor I now am going to have to get this ECU out to a specialist.
Sometimes a little knowledge can be dangerous, gutted

Peter,

Sorry to hear that you accidentally fried your ECM. How on earth did you stick a live power probe into the ECM? It's a bit like the stories you hear about someone leaving a tool in the engine cam covers, or dropping a soldering iron onto wiring looms. It hurts but easily done!

Your car has been dead for a few days now. My condolences, but at least in a big city like London, you probably can send the ECM out to a specialist repair shop. The starter motor replacement is an easy one. However, considering it's Easter, your car will rise from the dead too.

Good luck.

To answer the question about cycling the key, just turn the key to the ignition on position where the dash lights up, but not to start, and do it twice in rapid succession. This initiatives an internal reset.

P1260 update to BCM fault
 

So in a hurry, I power probed the wrong terminal of my starter relay even though I had already probed the correct one, starter motor is good, thought I blow the ECU? Sent my ECU off and it's fine, another look at the circuit diagram and I realise it's the Body Processor Module (BCM) that was probably at fault to start with now as the starter gets an ECU signal and the BCM was not turning the starter over and now I have blown up the BCM completely!
So I need to get back to that point to finalise this original fault and nail it to the key transponder or not. The bit the main dealer fitted recently, GRRRR!
These BCM's are coded from what I can work out, mine is a LLJE2500AB /147, ( Vcat number is the 147), The coding on these does matter it seems as it's matched to your cars accessories you have, cruise control, conv/ coupe, braking systems etc etc so going to need a reprogram regardless if I buy 2nd hand one. Or is it more simple either conv or coupe version as it appears resellers are saying stick straight in and it will work, but the bulletin says different, identical match?
1. So either I send mine off for repair, hoping it's not a write off.
2. Buy one from Ebay and have it re-programmed somewhere?

Option 2 is probably cheaper.

So can anyone send me;-
CONTACT DETAILS FOR;-
1. BCM repairer?
2. BCM re-programmer?
As I am struggling to find one for either, (UK car)

Summer is almost on us and still no car to drive please help me gents I am getting desperate :-(

Cheers Pete

Hi Pete,
The wiring for the vanity lamps is routed through the header rail and can get pinched if the sun visors have been disturbed as part of a hose/latch job. There have been several reports of BPM issues caused by this.

The problems you are having may not be related, but I would recommend that you disconnect the plugs under the centre roof console and test for short circuits there. It's a 0$ check and may save a replacement BPM from suffering the same fate. The circuits are fuse protected but occasionally the fuse holds and the BPM itself goes into meltdown.
See these threads:

jbhemm:
https://www.jaguarforums.com/forum/x...58/

lawnerd:
https://www.jaguarforums.com/forum/x...9/#post1011572

waldo:
https://www.jaguarforums.com/forum/x...1/#post1529951

Sellers likely won't understand the nuances of software versions so beware. I think the module can be opened without major surgery so I'd check that it hasn't suffered the same fate as Waldo's before sending out for repair.

It is the BPM that fires the starter relay.

Hi and thanks Michael,
Well that could be one fault, but I was careful with those as that's how the car came so that was one of my first repairs, I checked and they work so can't be shorting I would have thought. What I did totally wrong when I was in a hurry was short circuited my starter relay by a huge error with a power probe, No. 5 flicks the solenoid, I got distracted and stuck it no.1 the fuel pump all the usual whering stopped under the bonnet and the dash gave me a load of faults. Had the ECM checked, by a good firm got another BPM from a real decent seller I trust and the same issue, I did not think of the instrument cluster which is like in the middle of it all possibly?

Symptoms;-
1. 10 short beeps on turn ignition on, no starter, no clicks under the bonnet and no whering fuel system etc
2. Faults on dash, No ABS, No cruise, no anything basically and this;- 'INCORRECT PART FITTED'
3. Gear lever stuck in park now too.
4. ECU Won't communicate with my laptop now either and its been given a full bill of health

From what I have read and what I did, looks like symptoms of shorting out the instrument cluster possibly, but that is not in that circuit directly, the ECM / BCM are and they are both fine apparently?

Can anyone concur any of this this or know what you blow if you power probe the wrong bit of the starter relay as I am not sure now just what I have done or what to do next? Car is stuck outside the house recover and full surgery is out of my budget. This is a plea for help!

Are the sun visor vanity lights still working? If not, check fuse #7 (IIRC 15A) in the driver's side fascia fusebox for the stuck in park symptom. If it is blown, then you need to find the cause before replacing it.

Others will chime in here but the 10 beeps sounds like the AC complaining. Does the console display look OK?

edit: What is the at-rest battery voltage?

Finally solved it! I had blown 2 fuses, but I know I checked them previously, not sure how I did all this but the main issue was the fuse no. 6 in the Dvr side fuse box 5 Amp Key transponder fuse which is also the overhead console, causing the dash to read all those nightmares and key not to talk to the car and then the No. 5, in the engine compartment 10 Amp starter relay fuse. Back to the niggly little things next and panic over. Not sure why I always think of the worst every time?
Proper did my self over this time, never mind lessons learnt.