I've had a very strange thing happen a hand full of times over the past 8 years with my Lr3. The first time was years ago when my battery was getting weak, even if you have enough battery to crank the engine the entire dash would go goofy and even if you floored the gas pedal it would keeping idling with max speed of 1-5 mph. Like there was a computer governor activated that disabled the throttle.

New battery fixed it.

Fast forward in time to last week.
Since then I have new battery, alternator no issues.
I'm running my heated seats and it happens again (new battery) The dash is fine but it goes into that mode where I can't go more than 5mph. I check the running engine and its running fine, just no throttle.
The fix was to simple turn off the car and restart it. Then all was fine.

So it has something to do with the heated seats. Now I've run both seats this winter many times and it does not do it every occasion. Oh I also had my phone charging (quick charge) and seats on.

Theory - too much draw on the battery (even if brand new) can cause the computer to sort of loose its mind and go into some strange mode where it turns off the throttle preventing the driver from going faster than 5 mph even if he floors the pedal. My fix for now is don't run the heated seats.

Anyone have a clue as to why this happens for sure?

 

The car does not, technically, draw power from the battery when operating because the alternator supplies enough power to charge up the battery after starting and supply the power demands of the vehicle. So once started, the battery is pretty much just another item using power from the alternator.

So either your alternator, while new, is defective or you have a bad ground or bad positive power lead connection, etc, etc. But I have not heard of a programed mode that would cause this severity of a performance limp.

 

The LR3 is the only vehicle that I've owned where the battery seems to play a bigger role than other cars. Example on the weak battery it had power to run lights, radio etc but refused to even turn the engine over because the computer would not allow it. It must sens voltage is low and the computer sort of takes over.

Old cars sure you could take the battery out and they still run like you said, the alternator does all the work.

There is a low throttle mode that is controlled via CPU, not sure how it works exactly. Its like "you can only idle" mode with gas pedal sort of disconnected. Resetting the computer seems to fix.

Its fine now and will be fore years unless I start using the electric seats too much.

 

Sooo....you answered your own question? Is that really the answer since you have to resign to not using a feature?

Dubious....

 

Well I took it once and they found nothing and cost me. I could take it to different place, no LR dealers for 90 miles from here so its a bit of a ordeal.

It does not goof up on cue, most the time its fine. But I would think it could be debugged.