Help! ECU dilema

[tommi]

I posted last week about the Engine Emissions and glow plug warning lights on my 2003 GT TDI...

http://www.vwaudiforum.co.uk/forum/showthread.php?t=40523

So I decided to get the car checked out and was informed the ECU was faulty and needed replacing. I started to make some enquires into another ECU and in the end decided to go direct through a main dealer. When ordering the part I got through to the service manager who urged me to get other items checked out 1st as he said the ECU's rarely go wrong...

He said I should check the tandem pump, check for diesel or a smell in the oild which could point to a head problem... he also said spend £50 at a main dealer and get them to run official VW diags.

I'm now left with a dilema.. do I go ahead and payout nearly £1000 for a new ECU or do I take heed of his advice and get the other bits and pieces checked out? i.e spendng more money when I'm fairly confident I will have to replace the ECU at some point anyway.

The symptoms i'm experiencing are:

Difficult to start - at lest 10 seconds or so to crank the car over. Sometimes I have to try 3 or 4 times... whilst trying to start the needle on the revometer goes mad - sometimes it shoots up to 5k?

Engine Emissions Light - always on, glow light plug flashing, occasionaly the ESP light is also on?

Ince started, the car seems to run fine although since the conversation with the service manager I think it may be a very slight miss at low revs (between 1000 and 1500) I'm possibly imagining this though!

Arrrgghhh please help!

Tommi

[Crasher]

I agree with what he said, ECU failure is extremely rare, especially on the TDI. I have replaced exactly one and that was for another forum user a few weeks back. Blaming the ECU is the recourse of an unskilled and poor mechanic in most cases. Your symptoms do not appear to be an ECU problem to me but again I agree with the VW service chap, a proper fault code read first and post the results.

[tommi]

I agree with what he said, ECU failure is extremely rare, especially on the TDI. I have replaced exactly one and that was for another forum user a few weeks back. Blaming the ECU is the recourse of an unskilled and poor mechanic in most cases. Your symptoms do not appear to be an ECU problem to me but again I agree with the VW service chap, a proper fault code read first and post the results.

Thanks for your reply mate. The car is booked in with VW next Tuesday for 30 mins of diags.

I'll post up the results here.

[tommi]

Thanks for your reply mate. The car is booked in with VW next Tuesday for 30 mins of diags.

I'll post up the results here.

I had the car cheked out by an independant, here are the VAG-COM Fault codes:

16485/P0101/000257 - Mass Air Flow Sensor (G70): Implausible Signal

16706/P0322/000802 - Engine Speed Sensor (G28): No Signal (this was changed for a new part but mde no difference)

16989 P0605 Internal Control Module Read Only Memory (EPROM) Error

Tomorrow the car is going to VW for official VW Diags... I'll post up the results here.

thanks
Tommi

[Crasher]

Has it been chipped/re-mapped? I have seen that 16989 code before on a modified ECU. After seeing that report I now agree with the original garage who said the ECU needs changing, especially considering the G28 code will not clear. If there is no wiring fault between the G28 and the ECU with a new genuine (I hope) sensor fitted, then the ECU is faulty. It may need a new AMM as well

[tommi]

Has it been chipped/re-mapped? I have seen that 16989 code before on a modified ECU. After seeing that report I now agree with the original garage who said the ECU needs changing, especially considering the G28 code will not clear. If there is no wiring fault between the G28 and the ECU with a new genuine (I hope) sensor fitted, then the ECU is faulty. It may need a new AMM as well

Not that i'm aware of although it's highly likely that is the case. The G28 was a genuine VW part, happily, I saw it with my own eyes. I guess it's sensible to do the AMM after the ECU?

I'm still planning on sending the car into VW tomorrow - for the sake of £50 i'm happy to get a second opinion. Thanks for your help and advice, you are certainly well respected on here and I'm feeling more comfortable now that it is the ECU.. thanks again.

[Crasher]

I would change the AMM (for a genuine exchange unit) if it comes up as faulty on the new ECU or the vehicle lacks power after a new ECU and there are no codes. If you can find one, VW dealers will code in a used ECU for you.

[tommi]

I had the car cheked out by an independant, here are the VAG-COM Fault codes:

16485/P0101/000257 - Mass Air Flow Sensor (G70): Implausible Signal

16706/P0322/000802 - Engine Speed Sensor (G28): No Signal (this was changed for a new part but mde no difference)

16989 P0605 Internal Control Module Read Only Memory (EPROM) Error

Tomorrow the car is going to VW for official VW Diags... I'll post up the results here.

thanks
Tommi

VW had the car yeterday and came up with exactly the same diagnosis... new ECU required (and G28 - but i'm going to hold fire on that one!)

So unless anyone knows of or can get there hands on VW part no: 038906019KJ it looks like £900 outlay on a new ECU and fitting :-(

The other option is to remove the ECU and send it off for potential repair - VW recommmened an electronics company based in Hednesford, however i'm reluctant as i understand the sucess rate is fairly low??

That aside, where exactly is the ECU on a Mk4 TDI and wow easy is it to remove/refit?

thanks for all your help
Tommi

[Crasher]

ECU testing and repair is pretty useless in my experience. Testing has sent me round in circles many times with reports of an ECU being good when it isn’t and vice versa. Also I have had “repaired” ECU’s returned with the exact same fault as before when I know they are faulty so I have given up and only buy good used or exchange VAG now. The ECU is under the windscreen so the wipers and fragile scuttle trim have to be removed to gain access.

[tommi]

ECU testing and repair is pretty useless in my experience. Testing has sent me round in circles many times with reports of an ECU being good when it isn’t and vice versa. Also I have had “repaired” ECU’s returned with the exact same fault as before when I know they are faulty so I have given up and only buy good used or exchange VAG now. The ECU is under the windscreen so the wipers and fragile scuttle trim have to be removed to gain access.


Grrr... thanks for the info! looks like I will have to bite the bullet and get my wallet out then!

thanks again for your help.

[tommi]

For thos who are interested, here is a quick update - it seems the issue is not the ECU. The vag-doctor has been looking at my car tonight and by performing some real-time diags he thinks it is a mechanical or electrical problem.

He was seeing some strange behavoir and demands on the ECU, relating to crank speed, fuel pump, speed sensor etc when the car was cranking.

So back to the drawing board! anyone, any further ideas??

thanks

[Crasher]

Well that’s pretty vague, mechanical or electrical pretty well covers everything!

If that fault code 16989 is still coming up, there probably is a problem with the ECU, possibly due to re-mapping. I am currently fighting one like this at the moment and I have found it impossible to find a used ECU and a new one is out of the question so I am resorting to repair and reloading which is also proving stressful.

What codes are currently coming up?

[tommi]

Well that’s pretty vague, mechanical or electrical pretty well covers everything!

If that fault code 16989 is still coming up, there probably is a problem with the ECU, possibly due to re-mapping. I am currently fighting one like this at the moment and I have found it impossible to find a used ECU and a new one is out of the question so I am resorting to repair and reloading which is also proving stressful.

What codes are currently coming up?

Sorry I was pretty knackered when I posted last night - hence the crap post. Basically, the ecu seems to check out ok - I sent it off to him last week and he did all manner of tests, rebuilds, checksum fixes etc and even cloned my secuirty information to another ECU - which strangely also copied the 16989 error over too?? So yesterday he came and had a look at the ECU again but this time with the rest of the car attached! Using VCDS he was able to ascertain that when the engine was cranking, the ECU was not recieving any kind of siganl, then all of a sudden a demand would come in and the ECU would see the car cranking at 5000 RPM?? when the cranking settled down to about 1100 - 1200 RPM the car would fire.

So he seems to think it is a wiring loom issue or a mechanical timing issue.

He believes the ROM error on the ECU is being caused by it going out of memory range. He is also fairly sure the ECU has not been modified or remapped in any way. Another ECU he brought with him was also tested and displayed the same symptoms.

What part code is the ECU you are having problems with??

[Crasher]

038 906 019 HH but it is on its way back now and hopefully correctly programed. The issue with this one was some moron had reprogramed it too far.

[tommi]

038 906 019 HH but it is on its way back now and hopefully correctly programed. The issue with this one was some moron had reprogramed it too far.

I sent you a PM earlier - the guys in the PM had a HH last week when I spoke with them... you may want to keep them for future reference?!

cheers

[Vag36]

I know this is a real old thread, but did you get this problem sorted/ find out the cause of it ?
reason I'm asking is I'm getting the same three fault codes on my vw golf gt tdi 115 bhp,

Ive so far replaced the crank sensor and was still getting all the same fault codes,
So today I replaced the ecu with another, plus new clocks/ keys comfort control module,
Now I thought this sort my problem but it still won't start and getting the same fault codes?
hope your still on the forum and may be ale to help?

Everybody I ask are all seem to be scratching the head on it and don't want to touch it

[adamss24]

ECU is goosed, do as Crasher advised and get a used ECU, exactly the same part number- if possible and have it de-immobilised ! There are companies that turn that in the tune so the new ecu is plug and play. Alternately, a cheap super vag pro hand held code reader will read the PIN of the instrument cluster and with help of VCDS the used ecu will be easy to code for less money than you might think !

[Vag36]

ECU is goosed, do as Crasher advised and get a used ECU, exactly the same part number- if possible and have it de-immobilised ! There are companies that turn that in the tune so the new ecu is plug and play. Alternately, a cheap super vag pro hand held code reader will read the PIN of the instrument cluster and with help of VCDS the used ecu will be easy to code for less money than you might think !


Thats what hat I did and I still seem to be getting the same codes, god knows how??

[Crasher]

I remember that one I did well, it was a pain in the tailgate!

VAG, can you post the fault code report from yours IN FULL please.

[tommi]

Hi Vag36 and Crasher (good to see you still around)

I don't frequent the forums these days so you can thank the owner for setting up email notifications! Believe it or not I remember those issues well, it become an obsession trying to get it resolved. In the end, we couldn't find the source of the faults, after swapping ECUs, tracing out every inch of the looms, swapping sensors, we simply gave up. The car continued to run, albeit just a bit dodgy on cranking. Anyway, after a number of miles and regular servicing the faults just disappeared. And the car is still running to this day (now with 176k on the clock) with no repeat of the issues. I cannot say exactly what resolved the issues but the regular servicing and use of VW approved oil and spare parts helped.

Good luck in your quest. Please do keep us updated.
Tommi

[Vag36]

hey guys, crasher i cant do a print out as its not my vag software its on a friends laptop
i done a scan today with my handheld scanner and was getting internal rom error, and crank sensor fault codes, managed to get the car to start after almost a month off the road and left in my garage over crimbo!

when its running it runs perrfect without a hitch! but if i turn the ignition off and turn it on to sart the tacho will bounce and i know it wont start,
then i have to keep turning it on and off untill it will start without the needle bounce!

so far as above ive swapped maf sensor, crank sensor, ecu/new clocks comfort control module/ ignition barrel(with keys) also a new ignition switch, cleaned all earth points under battery tray, scuttle panel,

still getting the codes rom error and crank senso,,, talk about do ya head in haha

ive even done a operation on the wiring loom checking for chaffed wires, shorts from the ecu all the way to the crank sensor plug lol

if i think of anything else to add i will.

edit i did come across this on another site, god knows if its worth spending £80 or more on another starter motor to find out its not the fix ;(

*****Faults include ‘internal rom error’, but not to be confused with two faults that appear at the same time, ‘internal rom error’ and ‘vehicle speed sensor circuit’. When these two faults appear at the same time, it is the starter motor at fault .Very common on VAG diesels,NO NAME can get rid of ROM error and decode. We are also seeing a lot of Audi Bosch and Siemens 5 WK4 for decode*****

[Crasher]

I don't trust these hand held scanners and the garbage they spit out, can you at least get the fault code numbers that came up using VCDS?

[adamss24]

Just a thought, had a t5 1.9 tdi van in the workshop yesterday, the darn thing had a fault with the cam sensor, changed for a genuine one and still the same, it would have taken too long to crank. No syncro angle showing in VCDS (stuck on 0.0) + the cam sensor fault would not clear. Stuck a new battery on it and still not better, it would fire away when on booster but it took 5-10 sec cranking. Anyway, decided to read the flash from the ECU with my MPPS and then flash it again, my intention was to read and inject a little more fuel from cold so it starts better. Anyway, read the flash in slow mode then flash the original again in slow mode, guess what ? No more fault codes, everything works as it should, i can hear the lift pump in the tank on ignition and the car starts first turn !

[micheal balbrig]

Nice result.
Can you tell if the lift pump could be heard working with ignition on when the problem was happening?
Thanks in advance.

[Vag36]

I don't trust these hand held scanners and the garbage they spit out, can you at least get the fault code numbers that came up using VCDS?


Sorry for the late reply crasher m8.

http://s29.postimg.org/4pzpybohv/IMG_0216.jpg (http://postimg.org/image/4pzpybohv/)

http://s21.postimg.org/vck3fffw3/IMG_0221.jpg (http://postimg.org/image/vck3fffw3/)

this scan was done last night, i could only take a picture with my iphone as my m8 was on his way out.
going to run another scan later in the week if i can.

[Crasher]

So no comms with the engine ECU?

[Vag36]

So no comms with the engine ECU?

sorry m8 didnt post the first part of the fault codes that was for address 03 abs brakes!

here it is,http://s23.postimg.org/l7dt6r693/IMG_0215fix.jpg (http://postimage.org/)

still getting the bouncing rpm needle when trying to start,
so now after getting these codes up from vag im totally lost haha as you can see what ive done to the car in the earlier post n this so far
and still im no closer! its driving me insane!!! lol

[Crasher]

I can't get that link to open but I can just about make out it says no fault code found which is difficult to accept!