My 2011 XKR has been sitting about 2 months without trickle charging. When I attempted to start it, it won't crank, but I could hear the fuel pump working. I saw the low battery warning, so I decided to charge the battery overnight. It was 12.4V before I recharged it overnight up to 12.9V. The next day I tried starting it again and it won't crank still. I tried pumping the break pedal a couple times and pushing it hard with no luck. I tried the lock-unlock thinking it maybe an immobilizer glitch, still doesn't work. So I figured this could be a dead battery issue. I did an OBD scan and saw circuit lows and I thought these codes were definitely caused by the battery. So I bought a new Group 49/H8 AGM battery and installed it. I did the standard relearn procedure, and tried to start it. I hear a click and fuel pump sounds but still no crank. I rescanned the OBD and see that all the low battery related codes are gone, but 2 new codes appear: B100A-87 and B1009-87. I have ruled out battery issue, and I don't think there's an engine problem. I think it has gotta be either an electrical/grounding issue, computer issue, or starter issue. Everything else in the car works: door locks, windows, headlights, tail lights, turn signals, parking brake, AC, infotainment system, audio, radio, navigation, and dashboard screen. Has anyone ever encountered this problem?

 

Even new batteries may need a full charge with a proper charger (not a trickle). BUT have you tried pressing your foot very firmly on the brake pedal and then pressing the start button?

 

New battery has been fully charged. And I have tried the brake pedal trick.

 

Never, ever, pump the brake pedal! That makes it very difficult to start your XKR, as that high pedal increases the distance to close the starter interlock switch. You'll have to stand on your brake pedal with both feet and all the force you can apply to get it to start - and it might not.

Let your car sit overnight so the brake pedal can return to its normal position. The next day, get in the car while being careful to not step on the brake pedal. Press and hold the START button first, and then step on the brake pedal. It should start right up with a light tap on the brake pedal.

I know that the Owner's Handbook says to press the brake pedal first, but trust me and press the START button first. I've been doing that for many years and it fires right up with a tap of the brake pedal. Many other Forum members have followed my advice and agree.

See my old Post #2, from 2012:
https://www.jaguarforums.com/forum/x...se-time-57460/

 

Where did I say PUMP?????

 

You didn't but Jedy did!:-)

 

 

A B100987 isn’t a good situation. The B100A87 typically goes hand in hand with that. No other codes??
So, If you have replaced the battery with a fully charged battery and, if you touched the leads together before connecting the new battery

I would let (much like a POST: power on self test) the car perform its systems test: do not touch brake. press and release power button. wait for all dings, chimes, whirrs etc to stop. floor the brake pedal and leave floored. press start button. release brake.

Barring that, a deeper analysis is needed.

 

Apologies, I missed that in the first read of the OP's post.

 

This is narrowing down to either a brake pedal stoplamp switch (not outputting signal) or transmission selector fault (not detecting P or N position) inhibiting starting. Given the background of a partially discharged battery, I'd prioritise stoplamp switch over transmission selector.

The stoplamp switch mounted in the brake pedal bracket. There are two switches in the stoplamp switch which close when the brake pedal is pressed to output 'brake applied' signals. One switch connects a ground to the ECM and the second switch connects battery power from the CJB (Central Junction Box) to the AJB (Auxiliary Junction Box), ECM and EPB (Electronic Parking Brake) module. Failure will prevent starting.

Graham

 

Hi. I've had something similar - all electrics work OK, but starter won't turn the engine over - despite occasional 'clicking' from the solenoid. In my case it turned out to be the main engine to body earth strap was corroded, partly broken and generally of high resistance. Test by taking a jump lead and connecting between the engine (or gearbox) casing, and some bare metal on the body. Try cranking with this in place (replacing the 'real' earth strap). When I wised-up, I pulled on the old earth strap and it just came to pieces in my hand.

I replaced the strap with two "normal" straps (from local auto-parts store) doubled up - only available straps were skinny (for some tiny 4 cylinder vehicle!) in comparison with the original. I had to recover the eyelet from the old strap, as the bolt on the gearbox bellhousing is awkwardly recessed and required the special right angle eyelet.

Engine end - new strap (with reused eyelet)

Chassis end - new strap

Old strap

Crumbling old strap

I came within an ace of buying a new starter & solenoid, before I figured this out. Should have known - pretty much all my XKR electrical issues have had a poor earth in there somewhere.
Good luck.
MM

 

That's a good thread and does sound somewhat similar to the symptoms as mine, I'll make sure to check all grounds which has been suggested prior.

 

Bizarre - is all I can say. Brought the battery to a battery shop and they loaded tested this AGM 850 CCA with 1000 amps. Battery took it like a champ. They took a post polisher / cleaner to the posts and that's it. They said this battery is extremely healthy. Took it home & just put leads on the posts (not even tight) and had a volt meter on it while I had my wife hit the start button. Fired right up! Cant believe it! The only thing I can figure at the moment is the battery postes were slightly corroded and not making sufficient conection. Maybe the high current demand then caused a circuit interruption and loss of voltage that shut everything down?? This is a 1 1/2 year old battery and these posts looked absolutely fine prior. Even the teminals look new. But this is my only explanation I can come up with. I even called the battery company and asked if load testing the battery would have done something to the battery to make it work properly. They did not think so. Wow! Hope this ends up being it as what an ordeal. As they often say its often the simple things...

 

Glad to hear it. Whilst troubleshooting, had you removed the battery cables at any point? Had you done the well documented reset procedure which requires removing both cables? If your answer's no, then I reckon you unknowingly reset it which's why it worked when you reconnected the battery.

 

Hi Jahummer,
Over the course of this past week to two weeks, the battery had been removed and charged away from the vehicle, and then reconnected numerous times. Even a spare battery was tried. I am not sure I understand this reset procedure. I know how to reset the parking brake / brake pedal and windows…but none of that was done until the engine was started. Once hitting the start button to cause accessories to come on to look at the faults (hood latch and boot open) I then hit the start button with brake pedal to start the engine. This when everything then would go off.