Help! Driving down the highway tonight in my 2011 LR4 with 15K miles on it and the damn thing goes dark - all power is lost and I'm going 70 mph in pitch dark with everyone (kids / wife ) in car. I basically soiled myself. What the hell? I've heard of this happening before in P38s..? All electrics were lost. I got to side of road. Kissed everyone and as I was sitting there the car turns back on but with several faults - no brake assist, no stability control. It is a new car. Should not happen. This was life-death serious. Only thing I can think of is that while driving in the fog tonight, I had turned on my fire and aft fog lamps several times and noticed a perceptible click from the passenger side dash. As we are stranded in the middle of Ohio please send advice and help. Also, after I completely turned the car off (restarted it), the faults all went away. No way I am driving this thing tonight though. Thanks!!!

 

A dead battery won't do it. A bad alternator won't do it, because the battery takes over for the alternator.

Loose cables, try shaking them to see if you can replicate it.

Also any fuses or fuse links in the fuse box. Most Rovers have a box under the hood, and the "main" fuses are "bolt in" style, one of the small bolts could be loose.

IMHO this is a good time for AAA or towing insurance.

 

Thanks, Savanah. I checked fuses and wires this morning. Don't see or feel any issue but just a manual check. The only weird electric issue this car has had is that sometimes the hand held key wouldn't lock the car - would just beep. I thought maybe the valet function was on but no. I'm not familiar with this function. Usually when I turned car on and off, the key would go back to worki g "normally". Otherwise, this car has been fine. After last night's near miss, I am seriously going to consider selling the car. I hate to say it, but for a kids car, I see a reliable Infiniti/Nissan/VW in my future.

 

Please post your eventual findings and what the fix is.
Intermittent electrical faults can be a real PITA to trace. I suspect a trip to the dealer to have diagnostics done, or find someone who has a Hawkeye.

 

The other weird issue we noticed with the car starting a month ago, for some unknown reason, when engaging the left turn signal, the flashing turn signal lights would blink twice as fast as on the right hand side. As if this morning, after the power cut, both right and left turn signals flash at same normal pace. Weird and dangerous Land Rover gremlins.

 

Would check with dealer, could be a service bulletin. I don't have the shop manual on this one (just a mere moderator, not a factory pro). I recall that one owner had an issue with after market stereo drawing so many amps that the automatic electrical current limit system was interfering. The electrical system of the LR3 and the LR4 are much different than the older ones, trying to get more amps just when you need them and minimum drain on the engine, etc.

I work second shift, so half of my driving is in the moonlight on back roads, flashlight at my side. In the distant past I recall seeing a pulpwood truck limping home with a magnetic flashlight on each front fender.

As pilot in command you did a great job in a tough situation.

 

There have been issues with both the electrical connectors at the CJB and the CJB itself.

The Central Junction Box is the main fuse box, and body controller for the vehicle, if it, or its power supply goes out, crazy things like this can happen.

With this issue, especially coupled with the turn signal problem, I would be looking in this direction. The CJB is located behind the dash, and its main 3 connectors are accessible if the glove box is fully dropped. If you are so inclined, you can try just unlatching those connectors and relatching them, I have had just doing that take care of issues along these lines completely.

 

Thanks! Is that the same thing as what the dealer is referring to as the CPM - central power modulator? Land Rover Dayton OH, thinks it is a software issue whereas over the phone Land Rover Manhattan thinks it is CPM issue but says that if there was a CPM issue, a yellow warning would have shown on dash before the power blowout so they are also confused, etc. Bottom line is that I'm really disappointed that another Land Rover I have purchased has another catastrophic electronic issue (my LR3 frequently accelerated when hitting the breaks at a certain speed).

I'm scared to drive this thing but have no choice right now. Your advice is definitely appreciated.

 

I have not heard the term CPM, and the only thing that I can think they might be talking about with that description, would be the Battery Monitoring System, which is mounted between the negative battery cable and the battery itself. The BMS watches how much current is going to or from the battery at any given time (even when the vehicle is off to monitor for a drain) and adjusts alternator output accordingly. It is a better system then based purely on voltage.

I do not see how the BMS could cause this, as even if the battery were completely disconnected after the engine was started, the vehicle would still be able to power itself from the alternator(I do not suggest trying this, as it can cause damage to various ECUs)

...or someone just got an acronym wrong... did you talk to a technician or a service adviser on the phone?

Also, there are no known software issues that cause this, which is the only time that a software update would rectify the situation, as it would have to have been fixed in newer software.

If you consider yourself handy at all, I would try simply disconnecting and reconnecting the main connectors at the CJB, or if you want to see if this is the problem, without actually disconnecting anything, instead of unlatching them, just wiggle the wires around, and see if you can induce failure(obviously not while going down the road, but with the engine running so you're sure it's the same failure type)

 

So what was the noise like when everythng shuts off and the car is in motion?