Last week my 2012 TDV8 Westminster refused to open for me. It turned out that the battery was totally dead, only 3v across the terminals when I opened the car with the emergency key. I had used the car only 48 hours before and previously the car has stood for weeks without issue, so clearly I had a new parasitic drain from somewhere.

I fitted a new AGM 019 battery, and I bought a clamp meter and the GAP IID tool. The clamp meter showed me that I had anywhere between a 3 amp and 8 amp drain. So pretty big! It seems to settle more around 3 amps when the car has been sat and locked for a couple of hours.

I now have my Ctek charge plugged in to the car to keep it topped up whilst I investigate the problem further.

My GAP IID tool has thrown up the following fault code and the date it has stored is the last day I used the car:

“B102E-11 (6 Air Quality Sensor – General electrical failure – circuit short to ground”

So I think this looks like a promising culprit. The problem is, the workshop manual I have does not list this error code, nor even the physical location of a part called “Air Quality Sensor”.

Could anyone with access to a better manual than the one I have please tell me what this part is, and where it is, so I can unplug it and replace it, to see if that solves my problem.

Many thanks.

This could be what you are looking for, same fault code, some info on the FFRR thread in the link below, scroll down a bit as the tread has all kinds of work mentioned.

https://www.google.com/url?esrc=s&q=&a...RnBnm5mE7c

That DTC doesn't mean what you think it means - for a start, the sensor isn't on the 'permanently live' circuit, 'short to ground' means the output of the sensor is at 0V, not the power supply to it.
3A is quite a draw, you should be able to use your clamp meter to identify which of the distribution cables from the battery it is being drawn on, work out where they go (the wiring diagram will show the cable size) and then concentrate on the final circuits that are unswitched from that distribution point. A quick check of everything that is switched is actually 'off' will eliminate switching / relay issues.

It’s half way up the radiator on the right hand side from looking at this… towards the bottom of the thread, not the pics near the top

https://www.fullfatrr.com/forum/topic28100-15.html



Can’t type very fast 🤣 others responded now….. 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 very much for the replys guys.

My clamp meter tells me that the red battery cable circled in the photo below is the one with the 3 amp draw at all times. So that rules out the alternator at least. I think.

The 'hedgehog' is the dropping resistor for the HVAC fan, if you have background illumination staying on, then that could well add up to ~3A Use the interior lighting wiring diagram and work back from there concentrating on the circuit(s) you can see are staying on.

Thanks, this is what the car looks like even after being locked for 6 hours...

I don't have the wiring diagrams for your MY to hand - but, it looks to me like there may well be a problem with the lighting control switch, are there any other interior illumination lamps on? vent controls for instance?
It could possibly be the 'aux' circuit staying on, as that triggers the instrument cluster backlighting on the wiring diagram I have (for an earlier version, so may be incorrect for yours). Do you have any aftermarket accessories wired in? or a battery on charge that is backfeeding power through a socket?
Lots of questions I know, it's very odd if it is only the IC and the hazard light switch as there are other items that should be illuminated also...

It's dark here now and the car has been locked for over 6 hours so it’s a good time to go and have another look.
I've unplugged the Ctek charger (I have it hardwired to the battery with the plug connector under the front grille so I don't have to lift the bonnet) and had a good look around.

You can see from the photos below, the only things on are the screen backlight, the hazard button and one dim led in the rear high level brake light.


The photos were taken on my iPhone and the long exposure makes the leds look much brighter than they are, the sky looks almost blue for example, and its pitch black.

I appreciate your time in looking into this for me.

Can you hear the fan running constantly when switched off? The “hedgehog” as described is a common fault that causes a major drain of the battery.

Replacement is a doable project albeit a bit of a tight access issue under the dashboard on the drivers side.

The “hedgehog” is the FSR Final Stage Resistor. There are several 5reads on this and also some you tube videos on the subject.

I fitted a Merle 64 11 6 923 604 it’s also a BMW part 2012 tdv8 Westminster arrived Jan 19 gone Dec 23

200 TDi discovery bobtail gone
RR classic v8 bobtail gone
300 tdi Discovery 3 dr gone

I had the air quality sensor error as you have, and it was a pain to find the location and access is a little fiddly. It is also sometimes referred to as a pollution sensor, which ultimately helped me track down the right part.

For my 2011 4.4tdv8 FF the part number was JTF100130 which I found on JLR Classic Parts (https://parts.jaguarlandroverclassic.com/jtf100130-sensor-air-cond-ambient-air.html).

The sensor is on the front right hand side of the engine bay (when looking from the front of the car), you need to remove the air box and maybe one or two other bits but it was very easy in the end, perhaps a 20-30min job (and most of that would have been my fat fingers fiddling with the sensor). Current: Range Rover L322 4.4tdv8, Porsche 911 (996) Carrera 2, BMW 535d Touring, Skoda Fabia, BMW S1000XR

If it gives a clue, mine gets an EPB fault when driven through puddles which keeps the IC alive to show the EPB warning light which flattens the battery overnight if a charger isn't connected.

Mine's fault is suspected to be caused by water entry into the connector at the EPB module as the EPB etc loom was replaced when I installed an e-diff but being so difficult to reach I haven't yet R&R'd the plug. The fault usually disappears in a day or 2, presumably when the water evaporates.

Hmm... I wonder if there's any moisture in any of the lights or connectors somehow causing the LCM to do something odd - I don't have wiring diagrams for this MY so can't be much help with detective work.

I would start with unplugging the top stoplight, hoping that the hazard switch indicator might go off.

Thanks for all the replies guys. Significant progress made today (I think).

I decided to go old school and get my test light out and simply test for voltage on each fuse and pull them out one by one when I find voltage. I figured my draw is so big (2 to 3 amps), the various modules waking up and going to sleep again shouldn't be as much of an issue as when looking for tiny parasitic draws in the mili amp range. I'd just have to be patient.

Anyway, I have found that if I pull fuses 61 and 42, my draw drops to 10 milliamps. Amazing, so I’ve narrowed it down considerably. I now suspect the seat control switch pack, or the seat memory control module, as I think it is on fuse 42, and my GAP IID tool is now showing a fault with “memory position 3 recall – drivers seat”

Interestingly, if I put fuse 61 back in (leaving 42 removed), my draw is about 0.8amps, and my instrument display back light comes on. So I’m thinking that the seat switch pack is the issue, but somehow its causing the instrument cluster to wake up?