Hello Everyone.
Bought this car couple years ago now. Also I want to say I have another parts car, was my first Jag purchase. Both cars are same year, color inside and out. Did that on purpose as cars can vary. So at first the car ran perfect, still does when it starts. Now you can generally get in and it will crank the first time you turn that key. Turn it off, absolutely no crank, doesn't even click like if the battery is dead, as typical in every other car on earth but not a Jaag! Furthermore the light on the J-gate does not light up. Then the no crank happens. Aslo the deathscroll can occur, but not everytime. Now you can let the car sit for 15 minutes to maybe overnight and then you will get that one try to start the engine. If it starts it runs beautifully. Also when this happens no other indicators are there. The locks, unlocks, all the lights work, everything works but try to crank no dice.
Please don't tell me about getting a new battery or starter. That isn't the issue here. I have found a lot threads with this very similar issue/problem but every thread will not have a solution.

I have taken the J-gate from parts car, didn't work
Cleaned terminals, checked fuses, transmission cable is adjusted correctly, micro switch works on shift lever, New battery.
Are there any other connections I should check clean, replace/repair
Should I swap ECU or BCM from my parts car or is this really a poor ground/earth somewhere.

Thank you in advanced this issue seems very tricky. I just hope I can resolve this as it seems I am paying for a very beautiful lawn ornament. Thank you

 

Also inertia switch is good and reset
Replaced the brake switch also

 

Check the bulkhead connection on the P/S in the engine bay.

 

Yes I have done that also. I feel I have done all the "obvious" Jaguar quirky things. I will check again, but as far as top side connections i have disconnected cleaned wire brushed every surface and really scraped mounting points to ensure a very good connection is made. I know these cars are very sensitive to voltage. Any reminder of a connection is welcomed. Truth is I have gave this car 2 good honest tries and get mad at it. BUT I have mustered up some love for it again and want to give it a try again. Hence posting a thread.

Thank you Addicted2Boost

 

no crank is 100% dependent on the BPM, if there is a good key it will energize S terminal on the starter. if your test light doesn't light up on the S term it wasn't authorized to start, dual linear switch has the p\n for the BPM and another line for the engine that stops injector pulse.

these will crank with CAN down don't worry about the death scroll

 

There's the earth strap between chassis and engine to check if you've not done.

 

Has Service Action S484 been performed?

 

Excellent thank you guys. I love this forum, you guys helped with my last jag. I will report back in a couple days. thank you very much guys

 

Did you check the inline connector on the wire to the starter solenoid (circled yellow, RHD car):

 

I know you said it's not the starter, but why do you think that? It sounds like a solenoid failure to me.

 

Also check the power stud on the 'false bulkhead'.
It can get loose and overheat causing the spacer to melt and stud to lose continuity.

 

The P on the J-Gate will not light up. If it does light up It will crank. Most of the time it will start first try after sitting for 1 day or longer. Then will drive perfectly stop and turn it off, no crank. And it can take 15 minutes or a whole day before it will crank again. I can tell if it will start just by watching the P on the J-gate light up or not. Basically inserting the key turning to ACC and seeing if the Parking P lights up.

 

Sorry guys winter happened and got cold quick. I just pulled the Jag out and of course started drove it for 20 minutes fell in love again. Came home turned it off no crank. Sit for a day, starts up. Thank you everyone for your input

 

You need to read ALL the codes for the CAN bus.

A DUAL LINEAR SWITCH fault can trigger a no injector pulse or no crank.(probably logged in the TCM if present)
Look for a P1260 (key transponder not recognized) as that can cause a NO CRANK.

 

The next time it won’t crank and the P won’t light up, have the key on and put the shifter in neutral and see if it starts up then.

Concerning the Dual Linear Switch Bob is pointing out, the contacts can get dirty and out of adjustment. It’s on the right hand side of the J gate and the entire center console has to come out to access it.

 

It will not come out of park when the P doesnt light up. I have took it apart and manually put it in Neutral while also checking the micro switches. Still no crank

 

Today drove my kid to school going great until I turned the power on the heater controls to defrost the windows the car goes into failsafe mode idles for a bit then shuts off. Turn it off, the P on ja gate isnt lighting up, great. Cycle the key a couple times and comes back on starts up. Drop off and drive home not touching anything. Get home turn the car off and try to start again nothing but I get a beeping Er on the heater controls. Along with low brake fluid, failsafe mode, transmission fault, ASC not available and so on. I leave the key on in ACC position and go in and grab the other 2 keys I have. I come back out car has come to life the P is illuminated and car starts. Shut it off, no crank. I try all 3 keys I have nothing works. I am starting to think the car isnt recognizing the key or something in the tumbler itself, could be wrong.

 

@motorcarman When you mean read all the codes on the CAN bus, you mean OBD II correct.

 

All modules on the CAN bus are..........
INSTPK
Gear Selector Illumination Module (listen ONLY node on the CAN bus)
Engine Control Module
Vehicle Speed Interface Module
Gearbox Control Module
ABS/Traction Control Module

A terminating resistor is fitted to the INSTPK and ABS module for a resistance of approx 60 OHMS.
You can also check voltage for CAN high and CAN low.

 

These are located in the steering column. Sorry not familiar plus electric isnt my strong suit. But thank you this is sounding like the problem