Help needed re "HEAT" warning light & PFC

speedfreak · September 15, 2009, 09:53:35 PM

Hi all, really need help with the above please, I am a technical numpty so don\'t know where to start!

Had my FD3 for about 3 months now, & all going well, steady boost & good power & acceleration, although I was about to book a mapping session as I thought it may be running rich. Boost is/was set at 0.7bar.
Anyhow, had a long drive to London & back in heavy traffic for a lot of the way, ran like a dream, a couple of pops & bangs on the de-acceleration but nothing major, then just as I approached home there was an almighty backfire & the HEAT warning light flashed up on the dash a couple of times, accompanied by serious juddering. Now this morning I had an unavoidable trip out again, the car started fine, steady idle, drove fine, & not the weather to boot it to see if the light came on again. Thing is as the ignition was fired the apexi commander lit up & then its screen went blank, nothing, nada. The car has run fine all the way & back again, no major backfires but a couple of small ones, but no warning light flash. Just got back in & PFC commander still not working, although car seems to be running fine.
Anyone any idea\'s please? (sorry it\'s a long one).

neil_jdmr · September 16, 2009, 12:44:51 AM

Worth a check just to see if the plug has come out from the commander cable to the pfc. The pfc btw is mounted in the passenger side footwell behind the plastic cowling and the commander plugs into the side.

Ed_RX7 · September 16, 2009, 10:29:58 AM

check your sensors via the commander...one of them will be highlighted

trotter · September 16, 2009, 10:52:33 AM

The heat light originally was used to highlight excess heat (funnily enough) in the cat. Unburnt fuel (ie. misfire) will ignite in the cat and rip the catalyst matrix to bits. The heat light warning was probably the result of the misfire and not vice versa.

The PFC will flash the heat light for two reasons:

1) Excessive knock (a value of over 60) will cause the light to flash three times at 0.1sec intervals

2) Injector duty over 98% will cause the light to flash at 0.5sec intervals.

Ed_RX7 · September 16, 2009, 11:09:50 AM

doh...should have read the post fully....you cant check the commander can you!!!

speedfreak · September 16, 2009, 11:20:41 AM

Ok, just checked the lead from the commander & it had come loose, so plugged it back in & commander works fine!

Don\'t forget I admit to being thick, so don\'t know where to start reading the commander to see what the problem might be. Sorry!

Will add that car starts first time EVERY time, no smoke of any colour from exhaust & idle speed is steady & smooth,so praying that not toomuch damage is done.

Would any be prepared to give me a simple step by step check of knock on the commander please?

Really appreciate this guys, thanks.
Brook.

trotter · September 16, 2009, 11:43:45 AM

Quote from: speedfreak;641836Ok, just checked the lead from the commander & it had come loose, so plugged it back in & commander works fine!

Don\'t forget I admit to being thick, so don\'t know where to start reading the commander to see what the problem might be. Sorry!

Will add that car starts first time EVERY time, no smoke of any colour from exhaust & idle speed is steady & smooth,so praying that not toomuch damage is done.

Would any be prepared to give me a simple step by step check of knock on the commander please?

Really appreciate this guys, thanks.
Brook.

Go to "monitor" menu,
Pick any of the channel options
select "knock"

lol, sorry for being patronising!! Google the manual if you get stuck!!

speedfreak · September 16, 2009, 05:29:19 PM

Quote from: trotter;641841Go to "monitor" menu,
Pick any of the channel options
select "knock"

lol, sorry for being patronising!! Google the manual if you get stuck!!

No worries mate, I guess I asked for that!

I know how to get that far, but I don\'t know how to interpret what the display says from then, I mean, if I put it onto 4 channels, with knock on the top left, bat-v next, then water temp & boost, there are values showing for everything except knock, which is blank. Is this good news?

neil_jdmr · September 16, 2009, 07:05:08 PM

The knock reading should be in a bar graph but if you select the left arrow once the pfc is powered up that selects a peak hold function so your highest knock value wll always be shown.

Also to note is unless you get a knock flash on anything other than full throttle then its safe enough to discard it as engine vibration. I was getting regular knock of over 100 and the heat light flashing like crazy all on part throttle around 4k rpm, I ave since turned off the knock function on my pfc because as long as you have a good map then knock will not be an issue plus the stock sensor is useless.

speedfreak · September 16, 2009, 10:11:11 PM

Yes that\'s right Neil, that is why I was puzzled, but I will try what you said tomorrow. I really don\'t think it is knock though, tried it tonight & the bar graph didn\'t go over 25% across the display under hard acceleration.

I spoke to the previous owner tonight, & he reckon\'s it is running the base pfc map, & said he thought he told me as it would need mapping asap. He didn\'t, but at least I know now!!!

Does all that sound as if I can rest easy, & book a mapping session asap?

Cheers all,
Brook.

Eddie · September 16, 2009, 10:17:56 PM

GO to the sensor settings and see which has been high lighted, this can only be done once the fault ahppens i think?

my heat light comes on and in the sensor settings it shows the OMP out of range not a worry as i premix but when the fault happens check the sensor settings to see what mite be going on.

cheers

neil_jdmr · September 17, 2009, 06:08:22 AM

you can go to the sensor check function anytime and check all your sensor are functioning correctly but iirc the only things that will bring on the heat light are as previously said, knock and inj duty.

I suspect the flashing heat light came on due to the backfire vibrating the sensor giving you a false knock reading.

I personally wouldnt be happy running my car on the basemap so yes get into a tuner and get your pfc mapped for your mods, chances are you will come out with a smile and plenty more ponies anyway.

trotter · September 17, 2009, 09:16:08 AM

^^ wot they said.....

The knock sensor is just a microphone next to the engine block. It\'s basically set up to listen for a certain frequency sound which identifies knock. Unfortunately, all kind of noise can emit this frequency. It\'s my dump valve that sets mine off!!!

Also, if the sensor is loose then it will vibrate against the rotor housing and could set it off. So might be worth having a quick look to see if its OK - you\'ll find it on the right hand side of the engine (looking from the front) about halfway down - its about 2-3in long.

G

Aceman · September 17, 2009, 04:54:22 PM

Doesn\'t the Apexi flash the orange light in the middle for knock, whilst the heat light on the right is the CAT temp one??

Or am I confused on lights...

neil_jdmr · September 17, 2009, 05:54:56 PM

No mate it deffo flashes the right hand side, red cat heat light.

Quick flashes for knock
slow flashes for inj duty.

Also when the 8mm bolt that secures the uim on comes loose,its just above the knock sensor thats renowned for setting off the knock sensor. As is knacked engine mount/loose manifold bolts.