So the Fuel Burning Heater kicks in but then stops after 20 seconds or so.

Gap Tool says 0x0304 Circulation Pump - Open circuit or short circuit to battery.

I'm about to dive in as it seems a fairly simple error message. I'm going to check wiring and fuses etc and then go for a new pump.

Just wondering if anyone has had this issue and might have some tips before I launch into it? Previous life - 2012 L320 SDV6 - Got divorced, say no more!
Previous life - 2014 L494 SDV6 - Got nicked, without keys, watched it go !
The Duchess - 2007 L322 TDV8 3.6 Autobiography with 270K miles on the clock
The Bonkers One - Audi SQ7 V8 4L TT - It will pull your face off.

Hi Nick, how did you get on with this fault, as I have the same issue ?

Hi Andy,

Because this fault was not stopping me driving and the possible cure would mean a coolant drain I haven't attempted a fix as yet.
That said, I have a new coolant reservoir to fit which I need to do over the next week or two so I plan crack this error at the same time.

From other messages I've posted on the forum I'm led to believe the culprit is likely to be LR039070 which is the electric coolant circulation pump mounted underneath the Fuel Burning Heater itself. Or the wiring associated with it.

I'll message again when I get the job underway. Might be a couple of weeks or so.
Regards
Nick Previous life - 2012 L320 SDV6 - Got divorced, say no more!
Previous life - 2014 L494 SDV6 - Got nicked, without keys, watched it go !
The Duchess - 2007 L322 TDV8 3.6 Autobiography with 270K miles on the clock
The Bonkers One - Audi SQ7 V8 4L TT - It will pull your face off.

I also have this code and the FBH doesn’t seem to be working. I also have:

FBH-Fuel Burn.Heater

0x0E08 K-Bus breakdown


Very interested to know what the issue could be.

Hi Nick,
Did you manage to sort this issue out at all as I am about to go into it myself ?

Regards
Andy

Hi Andy,

Well that's a coincidence. The old girl went up in the air this morning and i'm underneath now !
I'll let you know how I get on. Previous life - 2012 L320 SDV6 - Got divorced, say no more!
Previous life - 2014 L494 SDV6 - Got nicked, without keys, watched it go !
The Duchess - 2007 L322 TDV8 3.6 Autobiography with 270K miles on the clock
The Bonkers One - Audi SQ7 V8 4L TT - It will pull your face off.

Lol, good luck

So then Andy after having established you need hands the size of Snow White's mates for this job I have some info, but I've not fixed it as yet.

I've got to the pump and tested it by applying 12v to its pins. I think my issue is not with the pump as I can hear it running and I can hear the coolant flowing.

I then tested the cables to the pump (there is a Blue/Green carrying the 12v and a Brown to earth it)
The Brown seems fine as it is short to the chassis.
The Blue/Green never seems to get any voltage no matter if I start the vehicle and manually switch on the Fuel Burning Heater etc.

My next plan is to trace the Blue/Green back to the ATC ECU as that's where I believe it ends up.

So the issue at the moment is; where does the ATC ECU live ?

I've got the service manual and a Gap IID so i'm trawling now.

Hopefully someone will see this and give me a pointer or two. Previous life - 2012 L320 SDV6 - Got divorced, say no more!
Previous life - 2014 L494 SDV6 - Got nicked, without keys, watched it go !
The Duchess - 2007 L322 TDV8 3.6 Autobiography with 270K miles on the clock
The Bonkers One - Audi SQ7 V8 4L TT - It will pull your face off.

Todays update:

There is no voltage to the circulation pump.

Have removed ATC unit from the dash and can confirm the feed wire to the pump has continuity. And the ground wire is connected to ground.

Therefore my supposition at the moment is there is no power being applied to pin 9 on the main connector of the ATC module.

Now I'm struggling ! - I assuming the fault is inside the ATC but probaly need some assistance from anyone who has knowledge of these units - are they fixable/testable/replaceable/coded ?

Helpppp !!! Previous life - 2012 L320 SDV6 - Got divorced, say no more!
Previous life - 2014 L494 SDV6 - Got nicked, without keys, watched it go !
The Duchess - 2007 L322 TDV8 3.6 Autobiography with 270K miles on the clock
The Bonkers One - Audi SQ7 V8 4L TT - It will pull your face off.

Well done for getting that far, where was the ATC unit located, and can you pick up a cheap one from ebay to test with ?

The ATC is the climate control button assembly in the dash. The wires from the FBH coolant pump end up here. It's easy to get out of the dash and not too bad to disassemble thereafter. Mine was fairly dusty but nothing is jumping out at me on the circuit board.

I can't find much info surrounding the PCB itself but I'm sure I've read somewhere the board is coded to the car ? - which means a swap out might not work ?

I'm reassembling now just to see if a clean has changed anything - I'm not hopeful ! Previous life - 2012 L320 SDV6 - Got divorced, say no more!
Previous life - 2014 L494 SDV6 - Got nicked, without keys, watched it go !
The Duchess - 2007 L322 TDV8 3.6 Autobiography with 270K miles on the clock
The Bonkers One - Audi SQ7 V8 4L TT - It will pull your face off.

So it's back together and things have changed - but I'm still no further forward.

The 0x0304 code has now been replaced with a 0x0344 code - GAP IID is just showing that as "unknown".

The vehicle is at some stupid angle with no coolant in it at present so I'm going to get it flat and put the coolant back in (new coolant bottle, which is why it's empty) and see if anything changes.

Update to the above: Back to square one, 0x0304 is back. Heater starts but never gets hot and then shuts down after 30 seconds or so.

I think we need help from someone who'se been down this road before us. Starting to think it's the heater itself - espcially as GAP IID manual indicates it can't tell us much about the FBH as JLR didn't fully integrate it into the OBD system  Previous life - 2012 L320 SDV6 - Got divorced, say no more!
Previous life - 2014 L494 SDV6 - Got nicked, without keys, watched it go !
The Duchess - 2007 L322 TDV8 3.6 Autobiography with 270K miles on the clock
The Bonkers One - Audi SQ7 V8 4L TT - It will pull your face off.

Last edited by nick4275 on 6th Nov 2024 4:18pm. Edited 1 time in total

I have actually changed out the ATC control panel in mine as I had a parasitic drain from the small fan inside it, I did not have to do any coding to the car at all.

Sorry Andy,
Didnt see your last post until I have already edited my last.

Have a look up there and you'll see what I've been up to.

I'm not convinced it is the ATC - I'm starting to lean towards the FBH itself.

I'm wondering if the ATC doesn't feed the 12v to the circ pump until after it has fired up the burner ??

If so then my burner is not firing so maybe the circ pump never gets a feed ?

Also the fact that GAP say they can't get all the data for the FBH it could well be faulty without GAP being able to tell ??

I hear you on the replacing the ATC and I think you're right it's probably not coded - but I'm not convinced it's faulty as yet. Previous life - 2012 L320 SDV6 - Got divorced, say no more!
Previous life - 2014 L494 SDV6 - Got nicked, without keys, watched it go !
The Duchess - 2007 L322 TDV8 3.6 Autobiography with 270K miles on the clock
The Bonkers One - Audi SQ7 V8 4L TT - It will pull your face off.

I think the pump mounted on the fuel burning heater is driven by the fuel burning heater. Theres is a second pump if I remember correctly mounted under / next / near the diverter valve assembly.