Factory immobiliser

[Tizedes 10]

Good evening Everyone,

 

 

I know a lots of topic about this but I cannot find the right information.

 

I have a 2.0 16v 1995 Rado.

 

Couple of month ago my car suddenly stopped after a few metres I could not start just after a few attempts.

 

Few weeks later first ignite in the morning. Switched on for a second after this stopped and never start since that.

 

Checked her with Vagcom 1 fault found 00546 Data wiring faulty, 27-00 Implausible Signal.

 

I have check all the wires I have tried the Wd40 trick on the connections but I cold not figure out What is wrong.

 

Any common problem what is case this or how can I disconnect the immobiliser?

 

Does anyone knows a good mobile car electrician around Heathrow?

 

Please help me I want her back :(

 

Any help much appriciate

 

Cheers

 

Adam

[vw rule 19]

Most standard immobilizers especially on modern cars are encrypted into the ECU,

the VR6 is also to a certain extent if it has one fitted from new.

 

On the later 2.0 16v Corrados they could be partially fitted with a similar immobilizer if fitted as standard.

 

You say you've checked the wiring and the multi plug connectors for any damage or water ingress.

But have you got a good earth as that can cause so many problems.

 

Can you hear the main high pressure fuel pump under car priming, you should hear this buzz for approx 6 to 8 seconds once the ignition is turned on, then once the engine is cranking over you should have fuel and a spark at HT leads/plugs.

 

Some immobilizers cut power from ECU or cut power to starter motor, fuel relay, ignition coil/coil pack/distributor.

 

Or on some of the 16v Corrados especially the early one's, think they had a separate immobilizer control unit, as possibly was an extra option from new by VW dealer,

this control unit could be behind glove box or up above fuse box ?

The real later 16v possibly had partially encrypted ECU but only on late 1994 to 1995 ?

 

I've got a later 2.0 16v ECU that you can have FOC I'll only charge you postage.

But you'll have to tell me what numbers you have on your ECU to see if the one I have is any good for you.

 

Hope this helps

Si

[vw rule 19]

Could be wiring fault somewhere,

or immobilizer control unit has gone,

or ECU has gone if immobilizer is partially encrypted into it.

 

Does the engine crank over when you turn ignition key, if so like I say have you got fuel and spark ?

You've got to find what circuit isn't working and trace back from there.

 

The Corrado ignition switch is a known problem if it hasn't been replaced, it varies but they normally only last 7 to 10 years, but this wouldn't normally cause your car to cut out, it normally gives symptoms of difficulty starting or dash lights are on when engine is running.

 

Hope this helps

 

Si

Edited October 25, 2017 by vw rule

[Tizedes 10]

Hi Si,

 

Thank you for your answer.

 

Yes the engine crank over but no ignition and fuel does not go to the injectors.

 

I have checked and I have a fuel income to the metering head.

 

She has a separate unit behind the dash. I have checked the connector on it and a cable are all ok.

 

Unfortunately it have already a lots of soldered cable and a I have checked those.

 

I think the earth is a shell I tried to disconnect that cable and Vagcom lost the communication.

 

The immobiliser cables goes to the same multi connector as the factory alarm but that one previously cut off.

 

Does the immobiliser has to have a negative connection to the battery or the earth is enough?

 

Ignition switched replaced as well after this problem.

 

Adam

[vw rule 19]

Hello mate,

 

I had this kind of problem on my Corrado 2.0 16v where the fuel supply was stopping sometimes or car just wouldn't start.

I traced it back to my fuel relay, and worked out it was the immobilizer / alarm control unit, that was burnt out on that circuit, I had to cut out / away the spliced wiring to immobilizer, and tried key and she started up.

Believe me it took awhile to trace the fault.

 

Si

[vw rule 19]

Hello there,

 

when you say you have no ignition, do you mean you have no ignition lights on dash, or no ignition spark at coil / spark plugs ?

 

Ok so you've got fuel to the fuel distributor on top of metering head, but you say no fuel at injectors.

So this means then your fuel distributor isn't firing, I think you have 2 connector plugs going to metering head.

 

1) is for the fuel differential pressure regulator/governor = which I think powers the fuel distributor i.e it regulates the fuel delivery pressure from fuel distributor.

 

2) is for the air flow sensor = on the back of this sensor there's contacts, that connect/measure movement from air sensor plate, this info is then sent to ECU to show how much air is being sucked/used in engine, then tells the governor how much fuel pressure to supply to fuel injectors.

 

Basically the fuel differential pressure regulator/governor,

and the air flow sensor both work together to obtain correct fuel delivery via fuel distributor. If one or both of these isn't working you'll have zero fuel delivery to injectors.

 

So sounds like power has been cut to fuel governor or air flow sensor or both of them, and possibly ignition coil/coil pack as you've said no spark at coil.

 

Have you checked for power and trigger signal, and earth.

 

Like I say you've got to see what has power and what hasn't, and trace correct wire / wiring back to ECU or immobilizer control unit,

possibly the immobilizer has been spliced i.e connected into fuel / ignition wiring from ECU ?

Once you find and see the circuit which has the problem, you'll need to cut out immobilizer and re-join wiring i.e so you don't have the immobilizer acting as a breaker cut off switch so to speak.

 

Si

Edited October 27, 2017 by vw rule

[Tizedes 10]

Hi Si,

 

I will check it at the weekend.

 

I mean no ignition spark at coil.

 

Thank you for your help.

 

Adam

[vw rule 19]

I've got the Bentley manual for the Corrado, but of cause it only covers the G60 and VR6 engine's. For service maintenance or for electrical faults/problems you can use this to get by for the other models as well, that aren't covered in this manual i.e the 1.8 16v and the 2.0 16v and 2.0 8v

 

I've also got another Bentley manual for the 1.8 16v and the 2.0 16v engines, also covers Golf MK2 8v GTI and a bit on diesel engine.

All from 1986 up to 1992

 

Si

[vw rule 19]

So looks like there are 35ish terminals on the 2.0 16v E-Motronic main ECU unit.

 

Terminal 1 =

0.5mm grey/white wire (goes to 6 point push on connector ground behind fuse box)

Then goes to 3 point push on connector behind centre console. Then goes to double white diagnostic connector plug under gear stick boot,

possibly up to 1992

After 1993 it'll be the OBD2 black connector.

 

Terminal 2 =

0.5mm blk/white wire (earth to behind fuse box) says six point push on connection.

Linked to battery to body earth.

 

Terminal 3 =

0.5mm violet/blk wire (goes to terminal 1 of coolant temp switch) in back of cylinder head.

 

Terminal 4 =

0.5mm white/red wire (goes to terminal 1 of differential pressure regulator/governor)

 

Terminal 5 =

0.5 brown/Black wire (goes to terminal 2 of differential pressure regulator/governor)

 

Terminal 6 =

0.5mm white wire (goes to 3 point push on connector near starter motor) then goes to terminal 1 of knock sensor 2.

 

Terminal 7 =

???? Possibly blank as not listed ????

 

Terminal 8 = has two wires.

0.5mm blk wire and 0.5mm yellow wire. **************

Blk wire (goes to 3 point push on connector near starter motor)

***************

Yellow wire (goes to 3 point push on connector near starter motor, then goes to terminal 2 of knock sensor 2.

Terminal 3 of knock sensor 2 is 0.5mm blk wire says is earth goes back in ECU main wiring loom.

 

Terminal 9 = POSSIBLY ONLY ON USA MODEL.

0.5mm blk/yellow wire (goes to terminal 1 of EGR temp sensor)

Terminal 2 of above sensor is 0.5mm brown/yellow wire says earth goes back in ECU main wiring loom.

 

Terminal 10 =

???? Possibly blank as not listed ????

 

Terminal 11 =

1.5mm grey wire (goes to terminal 2 of ignition module.

 

Terminal 12 =

???? Possibly blank as not listed ????

 

Terminal 13 =

0.5mm yellow/blk wire (goes to 4 point push on connector behind fuse box) then goes to double blue diagnostic connector under gear stick

possibly up to 1992

After 1993 it'll be the OBD2 black connector.

 

Terminal 14 =

1.5mm blk wire (goes to 5 point push on connector behind fuse box)

Then comes back out as 1mm blk wire, looks like an earth.

Changes to 1.5mm blk/yellow wire (goes to 6 point push on connector behind fuse box) which links to terminal 1 of ignition module.

 

Terminal 15 =

0.5mm green/yellow wire

(goes to terminal 2 of carbon canister solenoid valve 2)

Terminal 1 of solenoid valve is 0.5mm blk/white wire, says earth connection goes back in ECU main wiring loom.

 

Terminal 16 =

0.5mm brown/red wire (goes to terminal 2 of cold start valve injector)

Terminal 1 of cold start valve is 0.5mm blk/white wire, says earth connection goes back in ECU main wiring loom.

 

Terminal 17=

1mm white wire (goes to terminal 1 of idle control valve)

Terminal 2 of idle valve is 1mm blk/white wire, says earth connection back in ECU main wiring loom.

 

Terminal 18 =

1.5mm brown/yellow wire (goes through ECU main wiring loom, where it changes to 2.5mm brown wire and

0.5mm brown wire.

(Says ?? 2.5mm goes to THIS I'VE GOT TO TRACE YET ??

(Says 0.5mm goes to terminal 2 of carbon canister solenoid valve 1)

Terminal 1 of solenoid valve 1 is 0.5mm blk/white wire,

says earth connection back in ECU main wiring loom.

 

Terminal 19 =

1.5mm red wire (looks like this is main live power to ECU) says goes to 2 point push on connector behind fuse box.

 

Terminal 20 =

???? Possibly blank as not listed ????

 

Terminal 21 =

0.5mm red/blk wire (goes to terminal 3 of hall sensor)

Terminal 1 of hall sensor = is 0.5mm brown/white wire = says earth goes back in ECU main wiring loom.

This hall sensor is inside the ignition distributor = should have a 3 pin connector plug.

 

Terminal 22 =

0.5mm yellow wire (goes to 5 point push on connector behind fuse box = says earth connection)

then goes to 2 point push on connector behind centre console.

Then goes to single white diagnostic connector under gear stick boot.

possibly up to 1992

After 1993 it'll be the OBD2 black connector.

 

Terminal 23 =

0.5mm grey/green wire (goes to terminal 2 of air flow sensor)

Terminal 3 of above sensor = 0.5mm brown/white wire - says is earth connection goes back in ECU main wiring loom.

 

Terminal 24 =

Grey wire (goes to one point connector near starter motor)

Then goes to terminal 1 of knock sensor 1

 

Terminal 25 =

???? Possibly blank as not listed ????

 

Terminal 26 =

0.5mm grey/red wire (goes to terminal 1 of air flow sensor.

 

Terminal 27 =

Green wire (goes to ignition timing reference sensor/knock control sensor)

this is normally connected onto HT lead number 4.

Only on 16v eng.

 

Terminal 28 =

???? Possibly blank as not listed ????

 

Terminal 29 =

Red wire (goes to ignition timing reference sensor/knock control sensor)

this is normally connected onto HT lead number 4.

Only on 16v eng.

 

Terminal 30 =

0.5mm green/white wire (goes to terminal 2 of hall sensor)

This hall sensor is inside the ignition distributor = should have a 3 pin connector plug.

 

Terminal 31 =

???? Possibly blank as not listed ????

 

Terminal 32 =

???? Possibly blank as not listed ????

 

Terminal 33 =

0.5mm blk/green wire (goes to 2 point push on connector behind fuse box.

 

Terminal 34 =

0.5mm white/green wire (goes to 3 point push on connector behind fuse box)

Then changes to 0.5mm brown/red wire = says goes to white 12 pin connector plug with central rear location tab, terminal/pin 6 of white 12 pin plug.

 

Terminal 35 =

1mm brown wire (looks like this is one of the main earth connections for ECU)

looks like it goes to valve cover on back right, close to where the distributor is.

 

 

This is now all 35 terminal/pins listed for the 2.0 16v main fuel/ignition ECU.

Just one or two things to find now.

 

Si

Edited October 29, 2017 by vw rule

[Tizedes 10]

Thank you very much Si

[vw rule 19]

(Main power to ECU is terminal/pin 19) 1.5mm red wire,

you should have 12v DC here when ignition is switched on,

and still when key is turned to crank engine.

If no power then check fuses, just in case.

 

(Earth points for ECU is

terminal/pin 35)

1mm brown wire,

looks like is the main earth for unit. This earth goes through ECU wiring harness/loom possibly to fuse box.

This wire changes colour in harness/loom or from fuse box, (changes to 1mm brown/white wire) and goes to valve cover at the back on the right,

close to where the distributor is. Should be a small rectangle bracket with 1 or 2 threaded stud/s, there are several earth wire's bolted to it to ground.

 

If the two above terminal/pins are good, i.e you have live and good earth, then you need to check the following.

 

1) Ignition coil/coil pack.

so on the coil at the live end you should see where the HT King lead is attached.

Each side of this there should be two terminal contacts.

1 = - (minus)

15 = + (positive)

With a multimeter set to 20v DC put the meter across/between these two, you should see 2v for a few seconds with ignition on.

 

2) Ignition module control unit.

I think this has a 7 terminal/pin connector plug.

This unit is normally close to coil but on the back of bulkhead same side as wipers, possibly under plastic tray.

Or it could be right beside coil on a alloy heat plate.

 

Terminal 2 (-) earth

and

terminal 4 (+) I think goes to terminal 15 on coil.

check with multimeter pins 2 & 4 you should have 12v DC with ignition on.

 

If showing no power to coil or ignition module then could be your immobilizer is armed and has cut power ??

Or a broken wire / wiring fault somewhere.

 

Hope this helps

Si

Edited October 30, 2017 by vw rule

[vw rule 19]

3) Also you could check your hall sensor.

The hall sensor has a 3 terminal/pin plug on side of distributor.

 

1 is earth (-)

2 is possibly the trigger/signal

3 is live (+)

 

Using your multimeter again set at 20v DC check across/between terminals 1 & 3 ideally you should have 9v to 12v here with ignition on.

If no voltage is found then do continuity test below.

 

Looks like terminal 3 of hall sensor is partially linked to terminal 30 of ECU,

as it says check for continuity with ignition off between these two terminal/pins.

 

Terminal 1 of hall sensor is earth connection goes back in ECU main wiring loom

 

Terminal 2 of hall sensor is trigger/signal is linked to terminal 30 of ECU

 

Terminal 3 of hall sensor is linked to terminal 21 of ECU

i.e as live feed to hall sensor.

 

Hope this helps.

 

Si

Edited October 30, 2017 by vw rule

[vw rule 19]

A bit more info here if needed.

 

4) The air flow sensor is on the metering head on lower back side facing drivers inner wing.

This sensor has a 3 terminal/pin connector plug.

 

1 = live (+)

2 = possibly the trigger/signal

3 = earth (-)

 

Again check you have power to this sensor.

 

Terminal 1 of air flow sensor is linked to

terminal 26 of ECU.

 

Looks like terminal 2 of air flow sensor is linked to terminal 23 of ECU.

 

Terminal 3 of above sensor says is earth connection goes back in ECU main wiring loom.

 

*****************

 

5) differential fuel pressure regulator/governor.

This item is on the fuel metering head, on the front side facing the alternator pulley of air filter box,

it's normally got a thick plastic cover protecting it.

It says the pressure regulator is held in place by two ANTI MAGNETIC BOLTS, so I presume not to cause any interference,

as this sensor receives variations in resistance flow, from ECU via throttle response and air flow meter sensor plate,

plus signal from coolant temp switch.

 

Again you need to check this pressure regulator is working,

looks like you do this by checking the resistance flow via the 2 terminal/pin connector plug.

 

Or by terminal/pin 4 and terminal/pin 5 of the main 35 pin ECU harness lead.

 

Resistance readings should be 15 to 20 ohms

 

Also it says the pressure regulator/governor if found to be faulty CAN NOT BE REPAIRED as it's a sealed unit.

 

 

Hope this helps

Si

Edited October 29, 2017 by vw rule

[vw rule 19]

So like I say you've got to find what circuit isn't working and determine if it is 100% down to the immobilizer.

Remember to check your fuses as well.

 

Hope you get it running again,

if still no joy then like you've already said you might have to get a auto electrician to hopefully trace pin point the fault.

 

Si

[vw rule 19]

Hello Tizedes,

 

how did you get on.

Did you manage to get your car running.

 

Si

[Tizedes 10]

Hello Tizedes,

 

how did you get on.

Did you manage to get your car running.

 

Si

 

Hi,

 

Thank you for your question.

 

Unfortunately she is still not working.

 

I have tried much as i can but with no luck.

 

I have tried to find a local electrician or mechanics but soon as I tell them how old is the car they do not want to do the job.

 

I have a no idea what to do.

 

Where do you live? Would you mind to came and see the car (obviously not for free :) )

 

Thanks