Hi All,

I've never noticed the fbh kick in on cold mornings so I finally got round to investigating. I plugged in the diagnostic tool to see what errors were logged but it couldn't talk to the fbh ecu. Checked the fuse, all good so next step was to check the connections to the fbh itself. Took the battery and tray out so I could see the connections and noticed the power connector wasn't plugged in and was tucked out of the way. Hmmm!

Plugged it back in and as soon as I reconnected the battery the fan on the fbh started running and carried on running. Connected the diagnostic tool back up and I can now talk to the ECU but no faults logged. Looked at some live data but the outside temp was too high for it to kick in but things like coolant temp looked like reasonable values. I'm guessing it still might have some kind of ECU issue? I've had to pull the fuse (59) to stop the fan running for now.

Is there anything else I should check before assuming an ECU issue?

I know there are lots of fuel burning heater threads on here already and I've looked through most of them but they don't seem to cover the problem I've got or maybe my search skills are lacking

I'd imagine that any previous faults could be saved if the power has been disconnected, but for how long, I'm not sure.

No new faults will be generated until they happen, so until it gets the right condition to fire up again, you may see nothing.

Not an expert in this area though....... 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

Suspect the power was removed cos you maybe have the duff resistor fault - causes the fan to run every time you
lock / unlock, open boot etc .....

Still waiting to fix mine but living with the fan running each time.

Unnecessary quote removed

have a look at this,
http://www.the75andztclub.co.uk/forum/showthread.php?t=100297

Excellent find ironhorse  .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

have been using that site for a couple of years now for the odd FBH problem, look up french mike he is the guru he will always answer a PM

Thanks all for the replies.

Thanks for the link to the thread Ironhorse. I'll have a read of that whilst I wait for the temperature to drop to see if it that's my only problem.

Whilst waiting for the temperature to drop enough for the FBH to start I plugged in the diagnostic tool again and found a function to force the FBH on for 3 minutes. Wish I'd spotted this earlier rather than waiting until it got cold again!
This time a fault code was logged "Air Combustion Fan Short Circuit to ground". I'm guessing this pretty much confirms an ECU issue. From reading the thread Ironhorse linked to it looks as though I can get the ECU out without removing the entire unit.

they are a tight fit on the full fat (under the battery tray) i accessed mine through the wheel arch,

mine is coming up with glow plug flame detector when i scanned it ,is this the pcb board or the glow plug

read this a few times
http://www.the75andztclub.co.uk/forum/showthread.php?t=100297
do the tests below
http://www.the75andztclub.co.uk/forum/show...stcount=27

remove it from car and do some proper tests
You can check the glowpin with a meter, it should measure 0.3 Ohms - which is below the usable range of most meters, so expect it to show a short. The unit measures the resistance of the glowpin to determine whether it is burning, if the resistance it measures proves to be too high, then it might apear to fire initially, but then shut down. FrenchMike suggests this theory can be tested by connencting a 12v 21w (stop lamp) in parallel with the glowpin. Basically connect the bulb across a pair of sewing needles so you can spear through the insulation to connect to the glowpin wires or connect between the output of the FET driver and ground. Then see if it will run normally.

An alternative way to check the glowpins operation, would be to measure the total current the entire FBH consumes. There should be a large sudden draw of current, when the glowpin is powered up which should be around 15 to 20amps and the easy way to measure it is by replacing the fuse #59 with a meter, but that will not confirm its resistance is within spec. also if you put 12v to glow-plug it should get white hot within a few seconds
and only when you have the facts you could PM mike for a second opinion on the PCB
nige

I stripped my fbh and put 12v across the glow plug for 1 second to confirm it was ok.

Fbh problems 9 out of 10 boils down to the pcb and it's the same two resistors every time.

Lots of Fbh units have been binned and only needed a few pence worth of resistors changed!

I'm pleased to report that it is now fixed

As recommend in the earlier replies I got in touch with FrenchMike (from the Rover 75 forum) and sent the PCB board to him. You can remove the PCB with the unit in situ (once the battery has been removed). He diagnosed a faulty capacitor and a resistor out of range. I received it back earlier this week and fitted it today. Forced the unit on with my diagnostic tool and checking the live data it appears to be working ok and no new faults logged

I don't think it'll get much use now but it's good to know it should be ready for next winter.

Nice one.

Mike's got a nice little thing going.

Could anyone PM me French Mike's details please? Thanks.