Club G40 Forum

Technical => Electrical => Topic started by: NealPeal on July 10, 2018, 02:39:51 pm

Title: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on July 10, 2018, 02:39:51 pm
Hello!
I've been battling to get the warning light to stay off... 30 seconds after starting it flashes the ! light, I hope I'm right thinking this is a management error... (If it's oil-pressure I'll kick myself
I'm getting "unKnown error"

Control Module Part Number: 030 906 022 c  Component and/or Version: DIGIFANT0864
1 Fault Found: 07683 - Unknown Error Code  08-10 -  Control Limit Surpassed - Intermittent


Anyone point me to anything from this...
A new o2 sensor didn't change much, the exhaust is sooty and jumps a bit until it goes limp...

any help appreciated, can I ask if any of these measurements look sus?
(http://www.lightdiodedesigns.co.uk/QuickPics//vcdsMeasureBlocks.png)

Bestest's
Neal :-)
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: steveo3002 on July 10, 2018, 02:51:50 pm
-13 dont sound right
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on July 10, 2018, 04:55:45 pm
Paul did say that was normal to be weird, that's why I'd like a few "what yours' say" screenshots to compare.. When I've stuck a resistor across the sensor plug (about 1k) and made it measure 10' it still goes limp after 20 seconds ish…
 
I'm intrigued by the 1.6v, I've not managed to find any way of changing it. It'd be good if that's the CO pot and it is open-circiut I can look for that

The 0.49v o2 sensor is easy to trace, grounding the pin sends the reading low.

Can I check I am right, if the red light flashes that's an ecu fault..?

I was checking the earths a bit and taking my dvm anywhere near the engine makes it go mad flashing readings, even with both probes touching at the same point, esd picking up from somewhere... I had it between the battery and engine and when I saw a voltage I thought !Bingo!, but a jump-lead between those points still had the meter going bananas, until I stuck it behind the bulkhead

Maybe unrelated but big electro-magnetic spikes might be throwing the ECU, what d'you recon?
NEAL :-)
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: steveo3002 on July 11, 2018, 09:37:01 am
what does you tps show ..engine off pedal to the floor?
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: hayesey on July 11, 2018, 10:58:31 am
what do you mean by warning light?  There's no ecu fault light in a G40.

Getting a crazy reading from the inlet air temp sensor is normal.  The software just doesn't seem to decode it properly.  I usually see values of -20.

I don't know what that fault code is, not sure if VWTOOL.EXE would tell you more, that's what I always used.  Finding a list of G40 Digifant fault codes seems to be impossible.  There's a few lists for G60 Digifant I came across Google searching but none list that code.  E.G.

http://www.a2resource.com/electrical/codes/digifant1g60.html

The only thing I found is someone on a german forum asking the same question but no one answers it:

https://www.polotreff.de/forum/t/233938



Title: Re: Unknown fault code, are any of these measurements well off?
Post by: hayesey on July 11, 2018, 11:00:43 am
also, the thread I linked to in the other thread you have on the same subject lists what the code blocks are:

https://www.polog40.co.uk/forum/index.php?topic=213.0

the 1.6v you are seeing is the CO pot voltage will be stable unless you adjust the co pot manually.

There is no TPS on a G40.
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: hayesey on July 11, 2018, 11:08:48 am
Quote
I've been battling to get the warning light to stay off... 30 seconds after starting it flashes the ! light, I hope I'm right thinking this is a management error... (If it's oil-pressure I'll kick myself

the only thing I could think that would be is the oil pressure warning light.  There's no management error light, g40s aren't that fancy :)
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on July 11, 2018, 12:50:16 pm
Cheers H, appreciated! :-)
I'm not convinced it's the oil pressure light because I'd expect that beeping when I've left the wire off.. And it seems like an exact time from starting to blinking, like it's waiting for the o2 sensor to heat up..? There's plenty of oil flowing up to the rocker-box, I've got to do that gasket again! I can check by pulling the wire off, I did think that produced just a steady "on", I'll check

There's definitely a change in engine-attitude when the light starts to flash... I suppose I can try another pressure sender, worth a try...! And the exhaust is soot *black* and it's covered my new O2 sensor in soot (and all the plugs) after 30 seconds.! (I hope the head isn't cracked leaking oil into every cylinder equally or something, but it looks and smells like over-fueling, there's petrol in the air

But I have found the fully-open-throttle-switch isn't giving any changes on the meter on or off, ,the switches are making the click and the idle does what I think, but the ...
And sticking resistors in to change the CO pot voltage output (or unplugging it) seems to do nothing to the 1.6v, or anything else I've tried.

When I get back we'll have a look at the fully-open-switch.. If it thinks it's foot-flat I can imagine it throwing fuel in, especially at low RPM

Cool, the intrigue continues... I can't see that cat surviving so I'll probably have to frig the CO pot, if it works like that!
10 x 10^6 thanks
NEAL
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: hayesey on July 11, 2018, 01:24:28 pm
No G40 has ever had any kind of engine management light what so ever.  There is no way whatever you are looking at is an engine management warning light. 

what wire are you removing?  Can you get a photo of the light you are seeing?

The beeping only starts in addition to the oil pressure light above a certain RPM (2.5k if I remember correctly).   If there is a sudden drop or rise in oil pressure then it could well be coupled with a noticable difference in the engine sound as there's a difference in the pressure in all the bearing shells. 

If you think there may be a pressure issue then really you need to hook up a mechanical oil pressure gauge.  I run one on mine all the time mounted to the dash.

Where are you testing the WOT switch?  At the ECU connector or directly on the contacts on the throttle body?  In either case you should get continuity when the switch is activated.  But this will only cause a problem under full throttle conditions, it'll idle and run under part throttle just fine, you'll just get no power (and potential engine damage!) at full throttle as it wont be putting enough fuel in.
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on July 11, 2018, 01:45:06 pm
You are "that genius" Paul, I know to ask you stuff because I know you've actually done stuff in reality...….! 1 million million (a terra '10^12') thanks...!!!

Guess what, you've got me going! I owe you a BIG  DRINK!!

There was an pressure oil-sender, the charger one, if I leave the wire off there's a beeping and flashing, and it's crimp was a "bit" loose... The other one, if I take it off, waits 20 seconds to flash with no beep... There's a "warning control unit" in the instrument panel that controls the light and buzzer... I guess it waits a moment for the lower pressure (presumably the charger) to build up....! (but I will check the charger isn't throwing oil)

NO 1 LESSON for Me, assumption is the mother of all my fcups…! I must be remembering a different car, or place, or time or dimension..! My memory is *ravaged*, so it's great to ask someone with one at home...!!!

So now there seems no flashy light, no smell of petrol, no back smoke, maybe the new o2 sensor was OK and that was the actual fault..!

Don't ever trust my knowledge unless it involves MCU or C#, engines are just too much!!!

There is an output on the ECU for a light, I might just add one...!!!! If it passes an MOT I'd be surprised with a 15 year-old cat on, but I can hunt for the CO trimpot adjustment or just make it with resistors.....


YOU ARE THE VERY BEST, and thanks SteveO for the encouragement...
I do feel a bit daft, but hey, if you saw me on stage that's 10 times worse so I'm used to it.!
NEAL :-D
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: hayesey on July 11, 2018, 05:13:03 pm
interesting, so does it seem to be working all ok now then?  Bit surprised that disconnecting/reconnecting the oil pressure sensor can have any effect on the running of the engine, that system isn't even connected to the ECU it's a pretty simple electrical thing controlled by the dash clocks. 

Anyway if it's now working then it's now working so all is good!
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: steveo3002 on July 11, 2018, 05:29:07 pm
pretty sure the oil light wouldnt effect the running
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on July 12, 2018, 02:06:07 am
Yeah sorry, "fixed" I meant the light!! But if that's not a limp light, the new O2 sensor has fixed the over-fuelling it just needed blowing out I recon...

I was starting to wonder, (because of the soot and  it is still making quite clicky noises but maybe that's me being oversensitive), is the charger oil is actually getting through a seal worst case guess...
But then after I've had it running for an hour or 2 today to clear some soot and there's become much less soot being blown out with the condensation, and it doesn't smell as badly of various hydrocarbons... A new O2 sensor might even have cured that fault.. The first test will be an MOT CO and HC test reading...

I do need to get an oil-o-meter, maybe even mounted in the car. Always useful info, even if not for me

Upto recently the car's not been started 10 times since the engine re-fresh 10 years ago, the whole lot really needs blowing out. I am sure at the time I would have changed the oil pump along with the bearings, rings & and seals... If it turns out not good I'll be gutted after having the engine out!!

Cool though, I can go away without that on my mind... Just found the part number thread for 2 oil senders, I might just order them and pop them in when I'm back..

Cool, bestest's
NEAL
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: steveo3002 on July 12, 2018, 07:56:05 am
has it got old fuel in?  my g60 stood a couple of years and was rich as hell on old fuel , once some new stuff got through it was fine
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on July 13, 2018, 07:52:59 am
Old fuel? Funny that is.. !! :-D That would explain a *lot* yes, appreciated input rhere Steve!

Yes, the tank-dregs from when someone milked it (or the pump really did just fall off in the wind)  were very old.. Couple of weeks ago I had it only nearly start because of the bubblea few weeks ago..  That got mixed with the can of petrol in the boot of the same age - just to get it going...  it'd been in there 10 years must be...
And every time I've put more petrol in it's got a lot better, yes...!! I really hadn't thought of that, I am glad of your insight! Explains a bit more.. I recon I killed the old o2 sensor but for £15 really doesn'r matter to make it

Just the oil-pressure to check to fully rectify the un-known fault, I can't wait to get home and get a meter on it just to be sure it's the

All signs are positive, and thanks to the forum I am more confident about it it...!
Cheeers, drinks owed to you all
NEAL
(Anyone near Denmark hill come say hello :-P)
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: hayesey on July 16, 2018, 05:35:02 pm
so I decided to get my "new" vagcom lead working since the old laptop I had with an RS232 port is well and truly dead now.

I had some mixed results.  The reason I am doing this is that I seem to have a running issue now.

I kind of got it working but it seemed very unreliable, two things I found, I am using VCDS as I found that vwtool.exe wont work on any modern computer:

- connection was very intermittent.  I sometimes had to keep re-trying, unplugging & replugging the lead before it would eventually connect to the ECU and read codes.  I must have tried over 50 times yesterday and got it to connect twice.  In the "test" section, it said the latency was poor.

- I could only get it to work with the engine running, not just ignition on.

Neal & Steve, did you find this too or does it work reliably on yours and with the engine off (ignition on)? 

I am wondering if this is actually a symptom of my running issue and that there is either a wiring problem or an earthing problem or a problem with the ECU itself? I have a spare ECU on route to test.  I am going to test the loom next.  In my mind at least, a bad earth could also cause an issue with the serial communication between the lead and the ECU.
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on July 19, 2018, 01:08:04 pm
I can confirm my VCDS connected to a KKL connects, engine on or off, 100% reliably +- 0.01%..
So to document my "Engine Off" readings, it's not -14' here, but that's normal! (I am told)

(http://www.lightdiodedesigns.co.uk/QuickPics/Polo-VCDS/vcds-EngineOffConnected.jpg)

Block 1 to 3 -
(http://www.lightdiodedesigns.co.uk/QuickPics/Polo-VCDS/vcds-EngineOff1-3.jpg)

Block 4 to 6
(http://www.lightdiodedesigns.co.uk/QuickPics/Polo-VCDS/vcds-EngineOff4-6.jpg)

Bestest's
Neal
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: hayesey on July 19, 2018, 03:01:16 pm
could you post what is shown on the "options" screen after pressing the Test button too please?  Mine shows "poor" latency, I'm interested in what I should be getting.

Fairly sure I have an issue with my loom and/or earths.
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on July 19, 2018, 07:18:13 pm
(http://www.LightDiodeDesigns.co.uk/QuickPics/Polo-VCDS/vcds-options-test.jpg)
Yeah, excellent latency on mine, well spotted....
NEAL :-~
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on July 19, 2018, 07:30:50 pm
Here's my 2000 RPM stats after the new petrol... Much less smoke, a bit less rattly.. But still the oil-light to sort out...

(http://www.lightdiodedesigns.co.uk/QuickPics//polo-vcds/2k/2k123.jpg)

Cool, o2 sensor looks OK..
NEAL :-D
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on July 19, 2018, 07:45:31 pm
And at idle (blurry photo gets sorted tomo)
(http://www.lightdiodedesigns.co.uk/QuickPics//polo-vcds/idle/idle123.jpg)
(http://www.lightdiodedesigns.co.uk/QuickPics//polo-vcds/idle/4-6.jpg)
(http://www.lightdiodedesigns.co.uk/QuickPics//polo-vcds/idle/789.jpg)

Title: Re: Unknown fault code, are any of these measurements well off?
Post by: ereeiz on July 20, 2018, 11:26:54 am
Do you want to borrow my ECU? I don't have a spare one but I've yet to touch it since the gearbox shat itself, so realistically it'll probably be another month or something until I get round to doing something. It's got an aftermarket /PPP (not sure) chip in it I think but you're welcome to try it?
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on July 21, 2018, 10:50:16 am
I'd like to in the end if i Dont get joy thanks 10^6 but I'm too skint to be able to cover even the post let alone a replacement if that gets blown..
What im most interested in at the mo is the co pot value.. just a thought, is yours adjustable? Am i supposed to drill it out.?could you nip on yours and tell me the ecu voltage reading at rest.. i can change it with resistors, but what should it be?
Its still labouring at 3k just sat on the driive, i bet a run out'd do it good..
And I've got to check the oil pressure, I'll order a meter kit next giro day :-)
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on July 25, 2018, 04:39:26 pm
A bit over the top to measure the oil pressure!!
http://www.lightdiodedesigns.co.uk/QuickPics//pressureTestKit.jpg (http://www.lightdiodedesigns.co.uk/QuickPics//pressureTestKit.jpg)
That's why I normally get my dad to order things off ebay but it looked in a a nice box so I bought it, but 500psi! If it moves 1/10 FSD I'll count that as the engine is pumping OK, but I don't think it'll read anything for fuel pressure that's meaningful..
No matter, if the pipe fills with oil I can rest easy! :-)
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on August 03, 2018, 02:27:03 pm
YYYEEEEEEEEEEEHHHHHHHHHHHHHAAAAAAAAAAAA!!!!!!!!!!!!!!!!!!!!!!

The battle with the o2 sensor is won!!!
WOULD YOU BELIEVE?; EARTHING THE EXHAUST PIPE DID IT....!!!!

I noticed the resistance between probe-body and battery-earth was about 4 ohms... The same as the probe-heater...!!! So I stuck a jumplead between battery and probe-body, and suddenly the traces made sense...!!
(http://www.lightdiodedesigns.co.uk/QuickPics/LamdaScope/LamdaTrace1.jpg)
(http://www.lightdiodedesigns.co.uk/QuickPics/LamdaScope/LamdaTrace2.jpg)
Going up to .69v, down to .13!!!!!!!!!! :-D x 10^6 !!!!!!!!!!!!!

And the oil leak is *better* too, just hoping the drips are from the rocker-cover...!!!!
NEAL
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: steveo3002 on August 03, 2018, 09:28:10 pm
strange ...maybe bad earths on the stock positions as it should earth through the engine and then the earth points id have thought
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on August 04, 2018, 01:45:58 pm
So strange, everything is again *OK*, WITH OR WITHOUT the extra earthing.!!!!  If VCDS says the probe is at 0.47v it's not working I have found on mine... I think I might suspect that was the voltage drop because of the heater current
I am beginning to wonder about earths in general! The 3ohm measured is the heater resistance, hopefully just a fluke, or the heater wires are backwards and somehow referenced to earth..
Funny though, remember the top of this thread I said "Is -11' a normal inlet temperature and there was an answer "Yes", well now I've got a temperature of 10' we're cooking, maybe coincidence again, I am starting to doubt any logic

But at the end of yesterday there was quite a pile of black foam on the floor under the exhaust, carbon black and frothy... You can imagine I was thinking "head gasket?".. But today, the little bit of water that came out the exhaust was clear and no black... :-D  SO I HAVE MADE A DIFFERENCE...! From mega-rich to normal. I dunno how what or why it is but it is OK now I am sure.!
(http://www.lightdiodedesigns.co.uk/QuickPics/Polo-VCDS/newBlocks2.jpg)
Note the temperature!!! :-)
(http://www.lightdiodedesigns.co.uk/QuickPics/Polo-VCDS/newBlocks1.jpg)

:-)
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on August 08, 2018, 12:15:30 am
T.B. Angle? Is that throttle body angle? Seems a bit of a strange range of values...!
Any ideas Steve?
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: steveo3002 on August 08, 2018, 08:27:06 am
yeah if its stuck at 40 its not right....having said that when i first tested mine it went from 0-80 (ign on ) when you pump the pedal , smooth as silk and instant response , now its glitchy and takes a good 10 secs to respond , spare one just the same and mates car same again

dunno if its genuine fault or im thinking maybe the cable /software isnt loving it

dont be too concerned whats coming out the exhaust , it will take miles of driving to clear it

yes the earths need to be spot on , you could replace the one near the coil and alternator, and ive seen it mentioned to run a spare between the o2 bracket and battery post...get the fattest cable you can for the first two       
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: hayesey on August 08, 2018, 09:19:34 am
yes I've seen TB Angle on my VCDS, it's just decoding some value incorrectly.  I don't think VCDS knows about G40 digifant.  There's definitely no way it's getting a TB angle reading from the ECU, it will be something else that it's decoding incorrectly.

From what I've seen in the past using vwtool, block 2 value 3 seems to be ignition advance.  I think this list is fairly reliable:

display group 01
1 coolant temp (blue temp sensor)
2 engine speed (RPM, from the hall sensor)
3 lambda signal
4 injection period

02
1 coolant temp (blue temp sensor)
2 engine speed (RPM, from the hall sensor)
3 not for service dept (seems to be ignition advance, units in BTDC anyway)
4 engine load (map sensor)

03
coolant temp (blue temp sensor)
engine speed (RPM, from the hall sensor)
not for service dept (this appears to be inlet temp)
c0 pot voltage

04 the same as 03

05
coolant temp
not for service dept (seems to be inlet temp)
not for service dept (seems to be a temperature but not sure what)
not for service dept (seems to be battery voltage)
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on August 08, 2018, 02:12:05 pm
I couldn't get my lead to connect this week but i think windows update was running in the background thinking about it.. I'll try giving vcds realtime priority over a core to see if i can get back on.. Swarze Kat was processor heavy but that was setting every one and 0 of megs of SPI..
I found a drawing of a kkl lead and the 5v rxd and txd are just tied together so it should just be DMA async in and out at most 9600..

Does your tb amgle change with full-pedal with the engine off? I know my wot switch does nothing, was hoping that'd tell me...

I found a list of vw banks on RossTech, but they are unmatchable!!

Cool matey, appreciated
Neal
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: steveo3002 on August 09, 2018, 08:55:49 am
first time i used it ..ign on /engine off the tps worked perfect , 0-80 (im told 80 for max is normal) all smooth and instant , now its very glitchy on the one fitted , a spare one and my mates car , kinda points to the lead or software but what do i know lol
Title: Re: Unknown fault code, are any of these measurements well off?
Post by: NealPeal on August 09, 2018, 02:05:53 pm
Yeah no I'd trust the data coming out the ecu if its getting to the pc.. maybe it is just left open on the g.. maybe a pot on mine might help me find the wot problem is what i was thinking
 I'm struggling with connecting with the lead today too.. Stopping windows update has sorted the poor latency problem but still trouble reading blocks 8)

Ive now run 3x 5litres of petrol dry too, just on idle moving 20meters total.. its a monster!
Cool