ECU problems. Help

[Trx 33]

Right, i've just bought an Arosa sport Mk2 (arosabinns ex-car) and im having some problems with the throttle, it does NOT rev at all. Put the foot down and all it does is squirt a bit of fuel and fluctuate. The butterfly valve in the throttle body does NOT move at all. I have removed the body and plugged it into my Mk1 to test it and the valve SEEMS to operate perfectly on the other car.

I have tested the wiring according to the manual and all seems ok:

3.3.2 Test process

Detach the 6-contacts connector from the throttle valve control unit -arrow- .

Measure the resistance of the throttle valve activator between contacts 3+5. Target value: 3...200 Ω

the target value is not reached: Replace the throttle valve control unit -J338- .

the target value is reached: Test the voltage supply of the throttle valve control unit and

the wiring to the control unit ⇒ page 70 . the voltage supply and the wiring are OK:

Replace the engine control unit ⇒ page 104 .

Detach the 6-contacts connector from the throttle valve control unit.

– To test the voltage, connect the multimeter to contacts 2+6 of the connector, using the auxiliary leads of the -V.A.G. 1594 A- .

– Switch on the ignition. Target value: 4.5 V min – Switch off the ignition.

– To test the voltage, connect the multimeter to contact 2 of the connector and earth.

– Switch on the ignition. Target value: 4.5 V min – Switch off the ignition.

I have scanned with VCDS and this is the log file:

Thursday,06,June,2013,12:47:59:10074

VCDS Version: Beta 11.3.0

Data version: 20110801

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

Chassis Type: 6H - Seat Arosa

Scan: 01 02 03 08 15 17 19 25 35 56

VIN: VSSZZZ6HZ3R004889 Mileage: 175420km/109000miles

-------------------------------------------------------------------------------

Address 01: Engine Labels: 036-906-034-APE.lbl

Part No: 036 906 034 BA

Component: MARELLI 4LV 3410

Coding: 00011

Shop #: WSC 06441

VCID: 52AF7E7BB1CB

VSSZZZ6HZ3R004889 VWZ1Z0B2181942

10 Faults Found:

17989 - Throttle Actuator (J338): Basic Setting Not Performed

P1581 - 35-00 - -

17962 - Throttle Actuator (J338): Conditions for Basic Settings not Met

P1554 - 35-00 - -

17978 - Engine Start Blocked by Immobilizer

P1570 - 35-10 - - - Intermittent

17953 - Throttle Valve Controller: Malfunction

P1545 - 35-10 - - - Intermittent

17950 - Angle Sensor 1 for Throttle Actuator (G187): Implausible Signal

P1542 - 35-00 - -

17953 - Throttle Valve Controller: Malfunction

P1545 - 35-10 - - - Intermittent

17973 - Throttle Actuator (J338): Lower Stop not Reached

P1565 - 35-00 - -

17952 - Angle Sensor 1 for Throttle Actuator (G187): Signal too Large

P1544 - 35-10 - - - Intermittent

17580 - Angle Sensor 2 for Throttle Actuator (G188) Signal too Low

P1172 - 35-10 - - - Intermittent

16885 - Vehicle Speed Sensor: Implausible Signal

P0501 - 35-10 - - - Intermittent

Readiness: 1010 0101

-------------------------------------------------------------------------------

Address 03: ABS Brakes Labels: 6X0-907-379.lbl

Part No: 6X0 907 379 B

Component: ABS 30 IE CAN V004

Coding: 05603

Shop #: WSC 06441

VCID: 43814B3F7EB1

No fault code found.

-------------------------------------------------------------------------------

Address 15: Airbags Labels: 6Q0-909-605-VW5.lbl

Part No: 1C0 909 605

Component: 0S AIRBAG VW51 0H 0004

Coding: 12371

Shop #: WSC 06441

VCID: E1CD21B7446D

1 Fault Found:

00588 - Airbag Igniter; Driver Side (N95)

32-10 - Resistance too High - Intermittent

-------------------------------------------------------------------------------

Address 17: Instruments Labels: None

Part No: 6H0 920 900 E

Component: KOMBIINSTRUMENT RB4 V02

Coding: 00441

Shop #: WSC 00001

VCID: 2759FFAFEAC9

No fault code found.

-------------------------------------------------------------------------------

Address 25: Immobilizer Labels: 6X0-953-257.lbl

Part No: 6X0 953 257

Component: IMMO 0008

Coding: 00001

Shop #: WSC 00000

VCID: FDF57DC7D8D5

VSSZZZ6HZ3R004889 VWZ1Z0B2181942

2 Faults Found:

01176 - Key

07-10 - Signal too Low - Intermittent

01176 - Key

65-10 - Unauthorized - Intermittent

-------------------------------------------------------------------------------

Address 35: Centr. Locks Labels: 1C0-962-258-III.lbl

Part No: 1C0 962 258 AB

Component: 13 Zentr.Verriegel. 0003

Coding: 00017

Shop #: WSC 69002

VCID: 67D9BFAF2A49

2 Faults Found:

00668 - Supply Voltage Terminal 30

07-10 - Signal too Low - Intermittent

01131 - Control Circuit for Turn Signals

25-10 - Unknown Switch Condition - Intermittent

End ---------------------------------------------------------------------

Sometimes if i leave the throttle body unplugged for a couple of hours and plug it back in it will start and drive pretty much perfectly.. then it stalls and reverts to not working.

I can NOT perform a throttle body alignment because it says 'ERROR' when i try.

The engine on this car has been replaced approximately 10K ago with an ANW/AXP engine, The ECU is the standard one i believe.

I took the car to the garage to try and get it sorted but the owner seems to think there is no possible way to get the car running with that engine/ECU. I was told to scrap it for £150 and that i could get an identical working model for £600.

WHAT A LOAD OF HORSE SH*T!

All of this leads me to think that this is an ECU problem?

Does anybody have any suggestions what i can try to resolve this?

If it is the ECU (knowing my luck it will be) how would i go abouts switching/replacing/repairing it? Do i need a virgin unit or can i get a second hander?

Should the new ECU be for the original (AUB) engine or the new (AHW/AXP) engine?

Would i be able to get an aftermarket ECU to get the car to work and would this be a better option?

I apologise if this has been a MAHOOSIVE post and nobody understands any of it, i dont think i do myself

I'm based about 15 miles north of newcastle if anyone can recommend any garages that would take it on?

Any more information just ask and ill do my best to retrieve it

Dan

[Rich]

If you're actually considering paying to get this sorted then I'm pretty sure I could have a look for you. (this would cost you Coffee)

I'm collecting somethings from Morpeth in a week or so.

[Trx 33]

I work shifts at nissan so finding time to do pretty much anything is a bitch next week im 3 - 11:30pm then the week after 11:30 - 7am

Shifts suck major donkey balls.

I've rang up a couple of places that deal with mapping and dyno testing and whatnot but it dosent seem they can do anything about it

just dropped an email to http://www.ecutechnologies.co.uk/index.php so hopefully i will get a reply sometime tomorrow.

I've personally tried everything i can think of - multimeter testing, vagcom, part swapping, battery disconnecting, ECU disconnecting, throttle body disconnecting, shouting profusely at the damn thing etc. so i dont know what else there is to try?

[electricracer]

try contactating BBA-REMAN they can test each part so at least you can see whats working or not

their website also has a lot of good fault finding info and comon faults

[Trx 33]

Cheers, i've dropped them an email too

Done a bit more digging and might have found the cause/problem/solution.

The o2 sensor on this car has previously been severed and bodged up. http://forums.clublupo.co.uk/index.php?/topic/92949-drew94-arosa-sport-need-mk5-golf-gti-seats/page-3

'Help please! Epc light stays on gas pedal not responsive

01-11-2012 09:13 AM #1

So the other day I was getting an alignment done on my car and when I pulled onto the rack the 02 sensor wires were pulled out of the sensor and after I checked to make sure that it wasn't anything searious like gas or break lines I started my car back up and the epc light was on and the rpms shot up without even touching the gas pedal after replacing the o2 sensor the problem wasnt fixed and now when I start the car it sounds like crap and if I push the gas it doesn't rev up at all. I'm now stuck leaving my car in school trying to figure out what's wrong with it we used a scan tool and the code P2128-trottle/pedal position sensor/ switch E circuit high. Does anyone know how I could relearn the electronic throttle position or if anyone has experienced this and can help with how to fix it I would really appreciate it because I am stuck now and have no idea what I can do to fix it. I have already taken the pps out and opened it up and cleaned it out because I saw another thread saying that someone with the same problem cleaned the sensor out and it fixed his problem but It did nothing for me. Thanks for ur help in advance.'

...

'If you did short the O2 sensor wires, I'm afraid that you'll have to replace your ECU. (or so that's what I've mostly found)

When the O2 sensor wires short out, the way the ECU is hardwired, it critically damages the pedal/throttle control components of the ECU as well. Only solution so far has been a new ECU. Hope I'm wrong'

...

The O2 sensors are wired in w/ the pedal control (which makes sense, since it all relates to air, fuel, and calculated torque) in the ECU. Shorting out the ECU doesn't fry the entire computer, but takes out a hugely integral chunk of it. That's why the car still fires up, but the throttle goes spastic.

- Found this whilst digging around the internet and it sounds very similar to the problems i've been having, although this is for a 1.8T engine.

Think i was right to suspect the ECU

[arosabinns]

bit of better history for you.

The engine was never replaced its the original engine just fully rebuilt with new parts. You should of got the full service history and evidence to prove this.

It was rebuilt on 93K so its more like 16K ago.

And to replace the ECU you need to the transponder unit and key chip also.

And it is the ECU thats broke.

[lupoluke]

Email Andy at Blacksmoke.co.uk

He may be able to take a look at your ecu or send you one out with the Immo deleted so it doesn't require coding.

[Trx 33]

bit of better history for you.

The engine was never replaced its the original engine just fully rebuilt with new parts. You should of got the full service history and evidence to prove this.

It was rebuilt on 93K so its more like 16K ago.

And to replace the ECU you need to the transponder unit and key chip also.

And it is the ECU thats broke.

Top man, appreciate this.

Sent the ECU off to BBA Reman and it has been repaired, just waiting for it to be shipped back to me Happy days.

Also ordered a new rear lambda sensor as that was the suspected cause so ill report back (hopefully) mid week when everything works first time.. Heh.

The list of bits and bobs to sort out is slowly reducing, ill have to step it up a gear though if im going to have it ready for MOT next month.

New tyres (in particular front right), Front ARB, cracked spring, what i've been told is a crack but i actually believe is a grind in the chassis just above the front right driveshaft, replace HID's with standard lights and raise the front a bit fot the MOT. Unfortunately i live next to some monumental speed humps so it will have to be permanently raised just a tad.

Also got a saggeh headlining to tend to, just done the headlining in silver and it has turned out pretty well so this one should be a doddle, ill get pictures up as soon as i can because im pretty chuffed with it

Plans and ideas are definitely surging through my head so hopefully ill have it show worthy again within the next 12 months. I like to think i will anyway

[Trx 33]

Ok, little update:

Got the ECU remanufactured, fitted a new NTK rear lambda sensor then coded the immobiliser and it started, i left it idling then it reverted to no throttle response. I popped the bonnet and found the black and white wire in the engine speed sensor connector was not connected. Once i soldered it back together i started it and i was only getting one code:

17950 - Angle Sensor 1 for Throttle Actuator (G187): Implausible Signal

P1542

All it needed at this point was a throttle body alignment but it wouldn't let me do that. it came up with an error on VCDS

I could drive it at this stage, just the butterfly valve in the throttle body only opened about 40% tops, so i took it to the dealership (18 miles away) and they could not align it either. They said i should check all of the wiring.

I drove it home and started checking all of the wiring in the engine bay but it started getting late so i plugged everything back in and tried to start it for the crack. It started but there was no throttle response at all, the mixture was off and it was getting particularly hot at the manifold. It seemed like i was back to stage 1.

At this point i was 90% sure the ECU was fried again but the next day i got testing again, meticulously following all of the wiring diagrams and found pretty much nothing, then i sprayed all of the plugs and whatnot with contact cleaner and put it all back together, then connected VCDS back up. I scanned it, cleared all codes then scanned again. The codes stayed cleared, so i tried a throttle body alignment.

It worked.

The car started, revved and drove perfectly, no engine management light, no EPC light.. for about 8 miles, then the EPC light came on so i took it home.

I tried to start it and it was playing up again, both lights came back on, it starts but it needs an alignment but i am just getting errors again, it refuses to align.

This is where i'm at now.

2 Faults Found:

17950 - Angle Sensor 1 for Throttle Actuator (G187): Implausible Signal

P1542 - 35-00 - -

17953 - Throttle Valve Controller: Malfunction

P1545 - 35-10 - - - Intermittent

Readiness: 1010 0101

I kneed to know what to try now as i've fried my own ECU trying to think of what yo do next lol

Any suggestions?

I have access to:

VCDS

Workshop manuals

Wiring diagrams

Edited July 31, 2013 by Trx 33

[lupoluke]

Over lay a new wiring loom from the ecu to throttle body, doesn't have to be pritty it's just to see if it works, I'd say you have a dodgy connection. Has an aftermarket alarm ever been fitted. Also have you tried a different TB

An by the way you can't carry out throttl body adaption while the faults are still there which is why it ****s you off lol.

[Trx 33]

I've ran out of money so i cant afford any new parts - £90 for the rest of the month bad crack.

Im pretty sure there has never been an alarm fitted.

I've ran a continuity test along every wire from the TB to the ECU and there are no shorts or anything like that as far as i can find, i've also done the test on the brown connector in the engine bay, i think its connector T14a, cant remember off the top of my head though

I haven't tried a new TB but i've unplugged it and plugged it into the connector for silver and it appears to work perfectly, i have not tried an adaption though. Vice versa the valve wont work with the ignition on, i can't start it to test any other way as the TB's are surprisingly very different and dont fit each other.

I don't know if it is normal in the sport's, but when i have the ignition on and i press the accelerator, the valve has no response, even when the car is in a semi drivable state (i can start and rev it) it has no response when the ignition is off. I know on my silver one the valve will work when the ignition is on, so i'm not sure if this is a part of the problem or just a feature of the sport. All i can think is that the valve is directly tied with the injectors so having it disabled when the engine is off is a feature to stop any accidental engine flooding?

Edited July 31, 2013 by Trx 33

[arosabinns]

throttle body has been changed 4 times to see if that was the issue.

the ecu doesnt need fixing it needs replacing and everything else does.

best thing would be to strip it and scrap it

[Trx 33]

BOSH! - Update..

Took the car for an MOT.,

3 fails... or rather 3 pages of fails 23 fails in total and 7 advisories.

Set to work on them and whittled it down to around 5 fails and 6ish advisories.

Engine wise i have replaced the front and rear lambda probes, throttle body and ECU and it appears to be working, but with the lack of MOT i cant really take it for a drive to see if it lasts.

The reason the ECU failed again, this time, was due to the throttle body, it had corrupted the ECU when full throttle was applied, when i removed the throttle body and compared it to a working unit the valve rested substantially more open, plus there were scratch marks in the bore.

Fingers crossed for a new lease of life come the new year.