On occasion when I go to start my car, it will be completely dead. I have put a new battery in the car and occasionally it will do the same thing. I disconnect the negative lead from the battery, wait a few minutes and then put it back and the car starts and operates fine.
happened again yesterday after driving for 30 minutes. The car sat for an hour or so then was completely dead. Disconnect the terminal put it back and it runs fine. Cannot figure this one out.

 

Try this (I know it's the opposite of what the Owner's Handbook says, but trust me): When you get in the driver's seat, be careful to not touch the brake pedal. Instead of stepping on the brake pedal, press and hold the START button first, and then step on the brake pedal.

Let us know if that helps.

 

That’s interesting, I will definitely give it a try. When this happens though , it is completely dead. Nothing happens when you press the button at all. I take the negative off the battery. Wait a minute put it back and it runs perfectly fine. It’s crazy.

 

sounds like you have a bad ground point somewhere.

 

Not sure where to begin to figure that out. At first, I thought it was a drain on the system but the battery is fully charged even when this is happening. I wonder if the battery cables should be replaced

 

why would you suspect the cables? Go out here and download the electrical manual and service manual and you can start there:

JagRepair.com - Jaguar Repair Information Resource

 

thank you I will take a look. I have a load tester. The battery is holding a charge and the load does not bring it down very much so my battery is fine. I also have the icarsoft i930 diagnostic tool which shows every diagnostic test is coming back fine. No codes at all. The only hiccup is when the diagnostic tool is diagnosing the car phone and sound system. I’ll hear a small pop the car RPMs drop for two seconds the CD player quits playing for about five seconds and then it all pops back to normal. I guess that’s a starting point.

 

I now you started a second thread and I use OEM software so I don't know the iCarsoft tool, but when I'm scanning for DTC's using SDD, ignition is on, engine off. There are no RPM's. Maybe your tool tells you to start the car? Again I think the tool right now is secondary but if it is intermittent ground, I would think you'd see a DTC code. Guy gave you the starting point in the service manual in the other thread you posted. Your car is "behaving" like a loose or corroded ground, to me at least. It's a daily easy DIY, albeit slow process. You got this.

 

Thanks,Sean, I agree. Just looking for as much feedback as I can get because it is so strange that when I take the battery terminal off and put it back on the car runs perfectly fine. I thought if it was a bad ground, it would be a static problem and not one that just happens sporadically out of the blue. I will keep plugging away. I appreciate it.

 

:-). Many think time and money spent at the garage for “diagnostic” is a waste…. Only to learn that it is a methodical and time consuming process, aided by experience and deep technical knowledge.

But I disagree. “wiggling and jiggling” connections will present themselves as “sporadic” issues. Thus the importance of following the pinpoint tests in the methodical manner they are written. All the connections should be clean, tight and free from the prospect of wiggling loose.

There are different catalysts for deterioration (oxidization aiding bad grounds), and a honorable mention of wear. But they will all present themselves as unexpected resistance or a broken circuit.
(how many phone cables do you go through!?)
So, back to the pinpoint tests.
Best of luck.

 

Despite the car appearing to be dead, it's probably worth doing a full reset. Either disconnect the negative lead and leave it that way over night, or disconnect both leads and touch them together for a minute before reconnecting (note, that's both leads touched together without the battery being connected to dissipate any charge in the car). It's free and easy to try at least and has been known to flush out a gremlin or two.

EDIT : is it dead to the point that the window doesn't drop when you open the door, and the interior light doesn't come on? Presumably it's unlocking with the remote?

 

To make matters worse, the first time it did this, the remote was on its last leg and I went in the store to buy a battery for the remote and when I came out, the car was dead. It unlocked using the remote but barely and nothing else would function, window did not drop, no lights came on, etc.. I took the lead off the battery waited two minutes, put it back on, and it was if the car was perfect again. It just does this randomly regardless of how little or how often I drive it. The battery was tested when I got home and it was perfectly fine.

 

Guy, yep, I do agree. I found a jaguar expert, not too far from where I live in the country. Pretty amazing with this find not to mention they do ECU tuning, etc. so I have an appointment with them February 4. Gonna change out the pulleys, thermostat, tune it, and get to the root of this problem.

 

@Brewzky See Posts 3 and 4, above. Did you try it? What happened?

 

Stuart, I have not had time to start checking each ground just yet. The diagnostic tool is not showing any DTC’s. The car starts and runs perfectly fine right now. It could happen tomorrow or next month, you just never know. It’s not like a static problem or I think it would happen all the time. It does sound like a loose connection possibly the way it just sporadically pops up.

 

Did you read my posts 3 and 4?

I didn't ask you to check any grounds.

All I suggested was to press the START button first, before you step on the brake pedal.

 

The car has not acted up since your post to do button first then brake. It definitely starts break or Biden first when it’s operating fine. I will definitely try that if it happens again again, but the car is completely dead when it does this. I’m beginning to think the car does not recognize the fob, therefore doesn’t know to start.

 

Read what you wrote after it's posted. Autocorrect is not your friend. If you see an obvious typo, you have a short time to edit and correct it.

You wrote: "... It definitely starts break or Biden first ..."
Obviously, you meant "... brake or button..."

 

Lol. Brake or button. And no, Biden could not start it either.

 

As President, his Secret Service protection detail prevented him from driving his 1967 Corvette convertible on public roads. As a former President, he will still have that Secret Service protection, but will they allow him to drive to get ice cream?

The steering wheel shimmy is not caused by wheels that are out of balance.

And yes, he can take it with him!