hi all. My x350 2.7 tdi has been sat for a few weeks. My key fob buttons are not working but I can get in the car by using the key. I've checked by key fob battery is ok so I suspect the battery on the car is too low. When I open the car the alarm goes off. I want to get in the boot to jump start the car to recharge the battery but I suspect an immobiliser kicks in with the alarm so even if I provide 12v to the battery the car won't start?

Problem is I can't get in the boot. The button doesn't have enough juice to open so again I try the key in the boot lid but nothing happens, there is no resistance to the key in a lock (or even electronic switch).

Can I provide power in the engine bay to al least get the boot open? If so where and how?

A few months ago I got a spare key made and I've been using that but currently trying with the original but I can't see this should make a difference.

Cheers

 

Hi rjsharpy,

That's distressing that your key won't even open the boot at the boot lock...

If your car is equipped with a cigar lighter, some of the trickle-chargers come with a plug to fit into a cigar lighter socket, so that is one possibile way to recharge your battery and at least get the boot open even if the battery won't gain enough charge to start the engine.

Looking at the schematics, it appears you could also charge the battery by connecting the positive cable of the charger to the terminal with the Black wire at either the starter or alternator. Those wires are connected directly to the battery positive terminal. Connect the charger negative cable to one of the body ground studs, which should complete the circuit because the battery negative cable is connected directly to the body as well.

Hopefully other members will have some better ideas.

Cheers,

Don

 

Don't try to start with charger still connected.

Probably needs 12+ hrs charging.

Boot lock is supposed to be mechanical so should open but any small power feed will re-energise enough to open the boot.

Elec. guide shows everything and is free download in workshop manual.

 

Hi all,

Still got problems - I have tried charging through the cigarette lighter but I suspect the fuse has poped for this (I also suspect the fuse is in the boot which I can't get to)

I can't really get under the car to get to the starter. However in the engine bay there is another fuse board. On the underside of this there are two heavy duty cables feeding the fuse panel which I would imagine is a positive and negative feed (certainly one looks like an earth)

I have tried supply 12v to each of these terminals for 30mins but no joy. Am I correct in using these terminals and if so will I need to put it on charge all day to get enough juice into the battery to get the boot open?

Unfortunatley the car is parked in an area where electric supply is limited.

Cheers Rich

 

The trunk lock key needs to be turned a full 90 degrees to release. You may need to spray WD40 or some light lube into the tumbler and wiggle the key around. It is completely mechanical, so does not need a battery to operate. Of course, you can't use the green valet key.


I doubt you can trickle charge the battery from a cig lighter, as I think they are all switched - as in, they are disconnected when the car is off.


You can apply power to the engine bay fuse block to provide enough power to pop the trunk. There is a thread from about a month ago here that discusses the details.

 

OK all - Great news. I've got in the boot. After all my faffing with tryingto get charge via the engine bay fuse panel! The above trick with the WD40 andbeing able to get the key to turn 90 degrees has worked! Feel a bit of a plonkabut it felt like the key or something inside the barrel would snap. Anyway 5minutes of patience and easing the key backwards and forwards worked.

So once in the boot I removed the battery and checked fluid levels (all ok)Voltage was around 11.3v so low but not too bad but I know jags are very sensitiveto full charge. It's now on charge.

I took a used battery that was producing 12.4v (which load tested ok) A separatealarm had been going off whilst I removed the original battery. I put in thesecond battery and all alarms were going off. Turned the ignition key andnothing. I don't think the car will allow me to start with the alarm/immobilisergoing off and I can't get it to go off with the key fob (I know the battery inthe key fob is fine)

Any suggestions on how I can shut the car up and get it to start? I triedtouching both battery cables together when there was no battery attached. Alarmis driving me mad and a bit embarrassing where it is.

Cheers

 

11.3 is essentially dead. It may well not recover properly so expect further grief and to replace it.

 

With car unlocked, battery connected press remote key unlock button twice. If no success replace remote battery and try again. If no success try with doors unlocked, trunk closed, doors closed - turn key to start position then remove key and close all doors and lock car with key. Then unlock car with key.

To start the car you'll need a healthy battery.

 

All - Great news - kind of! I put the original battery back in last nightand alarm and key fob work as they should and I was able to start the car. Lether warm up for 15 mins before taking her for a steady drive. All seemed fineuntil I applied more throttle and 'restricted performance' came up. Stopped andswitched the car of for 10 mins. Started up again fine without the 'restrictedperformance' display until I applied heavier throttle again. Bugger.

Last time it did this I had a new turbo and actuator. I rather hope thatnothing too serious has caused this - The car hasn't liked being sat for 2months.

Cheers

 

The diesels do seem to need a lot of regular varied driving.

 

I have been warned off the 2.7 litre diesel by the garage that maintains my car. Too much trouble occurs to compensate for the lower fuel consumption.