The battery died in my G35, so I decided to jump start it with my LR3. I correctly connected the jumper cables and started the G35 up. I shut off my LR3 and all was good. An hour later I need to go somewhere, and when I start my LR3, I have an amber suspension light glowing, telling me I have a suspension fault and am stuck on 'Normal Height Only." When I turn it off, I hear what I assume is the air compressor making a buzzing/whirring sound. I just left it until the sound died. I tried hard resetting the LR3, but no dice. I've also tried replacing the F35 and F26 fuses with spares, but that didn't fix it.

I haven't used my baby for a month already, and now, even though it tells me that it's locked at normal height, it's actually as low as it is on access height or even lower, and when I drive, the car starts bouncing like a donk. The light is still amber, not red. I really hope it's not the compressor, since it worked fine before I jump started. It's a 2006 Java Black V8 HSE with 55k miles on it. Feel free to bash me, but I've never off-roaded on this baby. I just think it's one of the best looking SUV's.

 

Does it come on instantly after starting, or does it come on after a minute of running? Typically, when the compressor is weak, it takes a minute or two of vehicle running before the amber light. This is because the compressor has to run for a bit before the vehicle determines that the system pressure isn't rising fast enough.

If it comes on instantly, it may be another issue.

But of course, the only way to know for sure is to have the system checked for stored faults.

 

The odds are it was just bad luck or coincidence but I think the compressor has failed; as to why, well that is what compressors do.

You could try a hard reset but I doubt that will solve the problem.
You can also put the 3 on a trickle charger for say a week of night times; that will usually get the battery fully charged but most likely will not solve the compressor problem.

You said that your 3 has been sitting for a month without being used. I am surprised that it even started; sitting for more than a couple of weeks can drain the battery so the fact it even started is a near miracle, let alone you jumped a second vehicle. By the way, I expect the Infiniti also has a Denso alternator and probably the same CaCa battery construction that the 3 has; and worse, both have the same "smart" regulator, the root of all the battery and charging problems.

Anyway, for certain your battery is now very low and a low battery voltage does strange things to the 3's computers - does not wreck them - but they act odd. They seem to need a minimum of about 12.5 volts and lots of amps even though they run at 5VDC, sometimes the control systems draw up to 25 amps instantaneous, and a low battery cannot give that; the computers get unhappy and red lights go on.

A weak low voltage battery can also mean the air compressor draws more amps than it should - the relay is rated at 70 amps but if that much goes to the compressor, you probably have lost it.

Jump starting drops battery voltage and lots of the amps are being sucked over to the other vehicle. Not that it helps you, but I have two batteries in my 3; I jump start off the second battery but disconnect it from the primary system before I do so.

DISCO3.CO.UK Photo Gallery - Traxide Dual Battery install in LHDrive


Hard Reset Instructions

In brief, to start the hard reset process, open the hood but close all doors and let your 3 go to sleep - no radio display etc and no key in the ignition. This will take a couple of minutes and do not open any doors until the reset is completed. (I find that it is often a good idea to have the drivers door window rolled down and the key in my pocket whenever fooling about the vehicle.) Also when I play with a car battery, I remove any rings I have from my fingers, also my watch.

Disconnect the ground battery terminal from the main starting battery.
Disconnect the positive battery terminal from the main starting battery.

The reason for this order is if a wrench or loose battery cable ends grounds to the body, no arcing or other bad things happen.

(I assume that you only have one battery in your 3. If not, disconnect the others as well and leave them disconnected until after all is done.)

Connect the negative cable to the positive cable. (NOT the battery.) You will need a short length, (a foot or so), of light gauge, (14 to 18 gauge AWG, insulated stranded copper), wire to span between the battery cable ends as there is not enough slack in the positive and negative battery cables for the ends to touch each other.

Hold all together for about a minute or more, (at least two minutes), as you are discharging memory modules within the engine computer and elsewhere. Then it is suggested you then just let all sit disconnected for say ten minutes, (minimum five minutes), prior to commencing to put the battery cable ends back on the battery posts per the following order.

Reattach positive terminal to the main starting battery positive post.
Reattach negative terminal to the main starting battery negative post.

Start engine and hopefully no or fewer warning lights.
Reset time on the radio - note that the station presets are still there as not everything is erased. Nothing much else needs resetting either.

You can now connect up the other batteries if you have a multiple battery setup.

This is a link to a thread in disco3 re the hard reset procedure.

http://bit.ly/14WXXR1

http://www.disco3.co.uk/forum/topic19547.html

This is a link to a thread on Disco3Club re the hard reset procedure.
http://www.disco3club.co.uk/phpbb/viewtopic.php?f=67&t=3374