First 'issue' with the car since I got it..... I've already searched the topics here, so can discount a number of things, but here's the problem.

Alarm sounder randomly goes off - no hazzard lights - just the siren. This is with the car locked from only one press of the keyfob (not superlocked).

Unlocking the car and opening a door doesn't stop it.

I've even managed to start the car and move it down the drive with the sounder still going!

Checking back the topics finds a common issue with the bonnet sensor. However, I've now looked twice and cannot even find a bonnet sensor anywhere - this from someone who knows what they do and what they (normally) look like!

I've even gone into the settings menu and unticked the Alarm from the vehicle set-up menu, but it still goes off when it feels like it. Oddly, going back into the settings menu after the alarm has gone off shows the tick has reappeared, despite me turning it off earlier..... How the hell does that happen?

Battery is showing 14+ volts with the engine running and 12.7v switched off.

Help!!!  The older I get, the more I realise that people confuse wrinkles for wisdom

Bonnet plunger is on the drivers side near the suspension turret, nearer the windscreen.

Worth a check. 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

Thanks for that MJ! Thought I was going blind, or mad, or both!!

Found it and all appears well there. Have pulled the bulkhead forward a tad to slightly increase the height of the plunger, but I'm not actually suspecting this is the problem.

There was no notification on the screen to say the bonnet was open, and I'm assuming that this would occur if that were the issue?

Also, if it were the bonnet opening sensor, would unlocking the car, starting the engine and driving it down the road not stop the siren?  The older I get, the more I realise that people confuse wrinkles for wisdom

I didn’t try driving mine when I had the bonnet plunger issue, but I’m tempted to think it’s not the issue, as I think mine had hazards on. The sun warmed the bonnet up and tripped it. Good to check and rule it out though.

Mechanic leant on mine and bent the bracket down by accident…. Last time it did it. 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

Right..... It's not the bonnet sensor.

I actually disconnected it completely (having read about this on other posts) and it hasn't made any difference.

Each time the alarm goes off, the 'Alarm Sensors' box on the main menu has returned with a tick in it, despite me turning it off beforehand.

Can the siren be disconnected easily, as it seems to be where the problem lies? As I said in my opening post, there's no flashing indicator lights with the alarm siren, and unless I'm mistaken, the two always go together. The older I get, the more I realise that people confuse wrinkles for wisdom

Posting this here for anyone who suffers this kind of thing in future:

I took the car to my local indi who said that it could potentially be a faulty BBUS (Battery Back-Up Sounder), especially if it's going when the car is moving, but they'd need the vehicle in to investigate. Oh, and I couldn't get it booked-in until May!!! On top of that, he said that reading the OBD wouldn't give any idea about this kind of fault.....

Not content with this answer, I concluded that the only way I was going to get a night's sleep was to break the connecton to the BBUS. However, when you see where the unit is located on a 2012 car, it's impossible to get your hand to the connector plug without removing the brake fluid reservior and the ABS pump!!! I went to the tool kit and got a three foot long (10mm diameter) steel bar out of the garage and was about to knock the s t out of the connector to the BBUS when I had a moment of clarity...

The fault only occurred when the vehicle was locked, so I initially decided to leave it unlocked overnight. Then an idea presented itself - sit in the passenger seat, lock the car from the switch on the dash, open the passenger door, get out and lock it with the key. In doing this, the car was now locked, but the alarm wasn't armed. RESULT - no overnight alarm.

This morning, I went out and opened the doors from the keyfob without any drama. I decided to check the battery voltage before starting the car and a multimeter was retreived from the workshop. I stuck it across the battery terminals...... 12.15v

Started the car (no problem), checked the running voltage and it was well over 14v, so it looks like I have my answer.

Strange faults should always point to the battery first and foremost. The difficulty is trying to maintain clarity of thought with a bloody alarm sounder going non-stop in the driveway as it's getting dark! The older I get, the more I realise that people confuse wrinkles for wisdom

Primal screem time.....

Fitted new battery today (019AGM). Locked the car with the keyfob and left it for a couple of hours. No alarm - Result!

Turned the car in the driveway (as it was pointing into the garage for fitting the new battery), locked it from a single press of the keyfob, walked away and guess what.......

Back to square one and it looks like I'm going to have to get it booked in for investigations. The older I get, the more I realise that people confuse wrinkles for wisdom

This sounds incredibly similar to a problem I have with mine ( 2012 FF 4.4 tdv8 ). Part of me was absolutely convinced I was triggering some kind of special lock / alarm from accidentally pressing the wrong key on the fob. I definitely not super locking. I’ve unplugged the bonnet sensor.

Honestly it feels like it’s got a mind of it’s own, and I’m loosing my mind as I’m driving down the road with the blooming alarm sounding at 23:45 at night

Fortunately I live in an area where it’s not the end of the world if I don’t lock it ( famous last words I know ) - I’ll be very interested to see how the troubleshooting when booked in goes for you JMC

Oh man you sound like you've had a guts full!

OK, alarm siren is located behind the splash guard so, if you dont have mudflaps? its easier to get to the siren?

So, EAS to off road height... Turn the steering wheel left hand down... Im not 100% certain without looking but im pretty sure you can use a plastic scraper to pop out your wing inner wheelarch liner/splashguard, you might need to remove a plastic fitting clip or two? Then you can remove the wiring plug/change the unit for a used one... They are used is a gazillion ford & Aston Martin models BUT! From memoy, im pretty sure you need the same part number as is on your original sounder...

Let us know how you get on sir...

Sounds a bit like mine, randomly going off and IID showed it as rear doors being opened, which it obviously was not.

I stuffed a towel round the sounder Christian.


Current Cars
2011 Range Rover Vogue SE
2020 BMW M4 Competition
2019 BMW X4

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Just when I thought this had become a monologue, along comes a few replies!

First things first - Fuse 36 is your friend if your sounder is going off. Pull the (5A) fuse behind the glovebox and you won't hear another sound from the battery back-up sounder. The only downside to this is if you leave a door ajar and lock the car with the key-fob, you won't hear the car telling you that you've been a and left a door open. Net result is you will walk away with a car which is literally left open......

Now for some good news.....

While all this has been going on, it struck me that I'd noticed a bit of plastic surround had broken off at the fuel flap locking pin a few weeks ago. Investigating further, I was shocked to find that there was actually a small area of potential water ingress where the locking bolt bezel had crumbled. One thing we all know is that you don't want any water entering the boot area!

I found the connector in the boot (RHS above the fuse panel) for the fuel flap locking actuator and released it. Who needs a locking fuel flap these days anyway?....

Next, I opened the fuel flap and gave the whole locking pin surround a quarter turn in an anti-clockwise direction, released it and pulled it out. Note this isn't the whole rod which comes from the actuator - it's just a second rod and springy rubber boot arrangement which is about 1.5" long. I then got several bits of gaffa tape and covered the hole to prevent water getting in there.

The black plastic locking pin iteslf was all gunged-up and it wasn't actually doing the job of locking the fuel flap.

So, I've basically plugged a hole which, over time, could have resulted in all manner of water ingress issues. I've disconnected the fuel flap locking actuator and most importantly, I've replaced fuse 36. So far, it's been 24hrs of locking and arming the alarm and there hasn't been a sound at any ungodly moment.

The jury is out on this, but I'm hopeful (again) that I've found and solved the problem. I just don't have a locking fuel flap. Also, from trawling the web, it seems that US versions of the car don't have this feature either - presumably because their fuel is too cheap to need to have a lock.

Oh, and I now have a perfectly good battery sitting in the garage which has unnecessarily been replaced by a new 019AGM. I suppose there's worse things to have as a spare!  The older I get, the more I realise that people confuse wrinkles for wisdom

Last edited by JMC on 23rd Mar 2022 4:02pm. Edited 1 time in total

You're not going to believe this.....

After my last post (15 mins ago), I decided to take some pictures for the forum, as they make a hell of a difference when trying to help others.

So, here's the gaffa tape over the hole for the fuel flap locking mechanism:

Click image to enlarge

Click image to enlarge

Did you ever get to the bottom of this? I recently had the same and they think could be BBUS

Short answer is no!

I resorted to removing the fuse for the sounder and all was well. Then, after a few months, I discovered that the fuse (#36 IIRC) also supplied the 12v to the towbar connector!

I resorted to replacing the fuse as needed, but eventually ended-up just leaving it in.

Since then..... No issues!!

(If it goes off at 3am tonight, I'm blaming you!! ) The older I get, the more I realise that people confuse wrinkles for wisdom