I was thinking the same thing on the shift cable bolts. Even if the cable end came completely loose and the transmission was stuck, that still shouldn't cause the rash of electrical issues. Plus, if the transmission was stuck in P (as previously mentioned), that should still allow the starter to engage. You couldn't shift out of park, but it should still start if that was the only fault. Of course, we may be dealing with more than one fault...

Any evidence of water in the bottom of the spare tire well? The trunk lid seal is notorious for leaking, and the water collects under the spare tire. This can wreak havoc with the electronics back there.

I like the previously mentioned suggestion to check the ground strap connection next to the battery. The bolt securing the ground strap passes through the body into the wheelwell and the tip is exposed to road salt. This can lead to lots of corrosion at a very important connection.

I'd also suggest a good visual inspection of the big output cable at the alternator. These are prone to heat damage and can cause all sorts of electrical weirdness.

Woo hoo! You're making progress. Keep up the good work. Chasing an intermittent fault can be maddening. If you can duplicate it, that's half the battle and should make future troubleshooting easier.

Nope.

Haven't gotten to this yet. I'm curious how this could only be an issue in extreme hot temps though? This has been happening for nearly 3 years, but only when it's really hot. Never once has it ever occurred when it's just a little hot, cool, or cold.

Just thinking here...

No water issues in spare tire well.

Checked ground strap connection and cleaned it all up. It was in good shape, but maybe it will make a difference.

Thanks everyone for all the suggestions!

As promised and/or threatened...

Your wiring diagrams are here:

www.jagrepair.com/images/AutoRepairPhotos/x2062004en.pdf


My TheoryDuJour™ is to hook up a recording voltmeter at a critical location that is feeding 12v to the engine control module. I have a fancy Fluke brand meter that records min and max values, but will also leave a hefty hole in your wallet. Here's an off-brand for $40 that will work just as well. You don't have to get this brand, but you will want some sort of digital meter with min/max recording ability:

https://www.amazon.com/Etekcity-MSR-...+max+voltmeter

At your front power distribution box (under the hood, above the right front tire), hook up the meter's (+) lead to fuse F33 or F38. Either one should work. If it's hard to make a solid connection to the fuse, pull it out and insert a thin strip of aluminum foil so it sticks out from under one blade of the fuse. That should give you something to which you can connect the (+) lead. Connect the meter's (-) lead to a good ground on the engine block. Select DC voltage and set the meter to auto record.

Start up the car, let it warm up fully, hopefully on a hot day in the sun, AC running, etc. Do your best to duplicate the conditions that would cause it to die, although I'd hold short of parking in the Burger King drivethrough. And then wait. Wait some more if needed, until the engine dies.

Once the engine dies, recall the voltage recorded by the meter. See how low the voltage got and let us know. In case it's too high, let us know the max value, too.

In theory you could run this test with a regular voltmeter, but you'd have to carefully monitor it the whole time. Also, there may be a transient condition that drops the voltage down and if you weren't looking at that exact moment, you'd miss it. A min/max meter is the way to go.

Also, do you plan to do any of this troubleshooting yourself or are you taking it to a shop? If the latter, I'd love to see the look on their faces as you explain you want a certain test done because some guy on the internet suggested it...

It may not, but it's an easy and free check.

Why not? Do you imagine the bolts are slack enough to slip but still catch sometimes?

Yes. We've had people (though I'm thinking probably not the member in this thread) with oddball issues tracked back to loose bolt(s).

And of course no-start cars - even ones where the missing bolt was found on the drive under the car!

(The ZF in the S-Type is a part-mechanical, part-CAN bus one. It can be unhappy when the two disagree or it's getting a flakey signal from the mech part i.e. the shift cable.)

Maybe, I still wouldn't put it top of the list except as an easy check to eliminate them particularly as it stalled while stationary without the gear lever being moved.

I had a somewhat similar problem - not with an S-type but a different car - where everything would randomly go haywire. It turned out to be either the ecu or ecu fan (I think both were replaced).

Last suspect on these cars.

I've had the identical symptoms, i've narrowed it down to the tps.
this weekend it wouldnt drive more than a few minutes after restarting and would happen when moving my foot off the accelerator. it would go into limp mode but engine would stall.

current workaround has been to disconect the battery. adjust the acelerator pedal position sensor to its maximimum forward postition and rotate the tps forward by aprox .5mm. then rotate the throttle position sensor forward slightly leving the screws just tight enough to hold it in place. reconect the battery and try to start the car, adjust the tps each time until the car will idle. when the car will start close to idle speed secure the tps then disconect and reconect the battery again.

positive result was i drove home in a virualy different car sprightly and responsive without the limp mode kicking in

downside is the abs and cruise dsc warning lights came on probably due to the voltages beeng outside the calibration rang
bear in mind this is on the side of the road and no test equipment 150 miles from home.

will update once i've replaced the tps

You're almost certainly not doing any of the right things there.

Kinda sounds like you and the original poster have different scenarios. Her car would randomly die and then all the fault messages would appear. However, I don't think her car ever went into restricted mode, either before or after. No fault codes were found.

Meanwhile, your car went into restricted mode first and then stalled. You should have had a corresponding fault code stored when restricted mode was triggered. I'm not saying the TPS couldn't be her fault, but we might be comparing apples and oranges.

Diagnosis for the original poster would be a lot easier if a fault code was present.

I am having a mysterious stalling /limp mode issue with my 2005 s type. I'm fighting thru best I can. But although our car is a like new exterior and interior and sleeps in the garage, I am not confident I will be able to win a lot of my electrical mystery issues. I am reminded of a favorite movie scene from "No time for sergeants " with Andy Griffith. When he tries to figure out how to work the radio in an airplane, he tells his buddy the thing to do is "SPIT IN THE BACK OF IT AND WHOMP IT A GOOD ONE!"

Sorry I've not responded for a bit. We had a nice batch of cool weather, so the car was running like a charm. Meanwhile we were waiting for a voltmeter to arrive that we'd ordered.

Hot weather returned, and we were able to hook up the voltmeter, and run the car for a while, brights on, air blasting, radio for entertainment , and finally cause the stall problem to occur. The voltmeter never fluctuated from a 13.4 reading ( I think that's the number my husband said. Regardless, it never fluctuated.)

We noticed on Carfax that the prior owner had the engine control module reset once, although we don't know why. We are going to make an appointment with the Jag dealer to do this again. It can't hurt.

Meanwhile, we need to get it up on a lift to try some of the other things. Again, thanks for all the help.

Every car has a button to allow moving gear lever to any position in case of dead battery or "no key" condition. I think it is under cupholder or under cover around gear shift lever. Who knows?

Yeah, that was our understanding, too. So far we've been unable to locate one, the manual is no help, and neither is the service dept at the Jag dealership.

No such button on an S-type AFAIK.