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  1. Bellaz

    Bellaz New Member

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    Hi, wondering if someone could advise what I should try next.

    I have an Astra 2.0 DTI on an 03 plate engine (Y20DTH). I have replaced the engine block & head. I used the timing tool set to fit the Cam and Fuel injector pump. The engine cranks over but fails to start. I flattened two batteries trying to kick it into life. I had both the Engine management light & Service spanner on. before coming to the conclusion that the car is immobilised.

    I checked the ignition key, replacing the battery, it was then the Spanner started flashing confirming that it was 100% immobilised.

    I tried calling local Auto electicians in Poole area with the same answer, they dont have a TECH2 and I should take it to the local vauxhall dealer. Fat chance of me taking it there as they mis-diagnosed the original problem leading to me purchasing and replacing the engine block.

    Anyway I then purchased one of those £60 TECH2s (OP COM) from ebay. Very helpful, as it reported numerous Diagnosic Troubleshooting codes 3 of which were immobiliser codes, and 3 related to the ignition key. Was not successful in reprograming the original key, key coming up transponder failure, maybe from the soldering I had to do to get the conductive battery connectores refitted. I resorted to ebay again, this time buying a blank ignition key & transponder. I took the remote fob and transponder and fitted these the the original key. I erased and reprogrammed the Immobiliser, ECU and Key. This time all successful and I get the correct messuring blocks being reported "Correct TP Key". Additionally all DTC errors are no longer being reported.

    Still the car will not start.

    Please could some one advise me what should I check & try next?

    Many thanks.
  2. adder_noir

    adder_noir Active Member

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    Hmm.... it makes you wonder if something is still lingering in the software which is immobilising the car. Are all fault codes absent now? I wonder if it's possible that even though they're not being reported by the car, are they perhaps lingering in memory somewhere and the ECU will not function if it finds immobiliser related codes in memory.

    I've just read in another thread that after sufficient key turns after fault code fixes the memory will clear.

    I notice you mention you had to do some soldering on the key. If you mean the bit where the battery locates to the circuitry I've had to do this when I pulled it off when trying to change the little 3V battery. As I understand it this part only relates to the central locking, I don't believe it transmits anything to the immobiliser. The keyfob has to be married to your car for the c/locking to work.

    However, the part in the keyfob relating to the car being able to start as I understand it is the little black chip which sits at the front of the plastic housing behind the metal part of the key. This does not need to be powered so I was wondering how you doing any soldering could affect this? The black chip just has to be present for the car to start as far as I know. I don't think there's any electrical contact involved as with mine I can pull it out of the keyfob and it's just a small profiled chip which sits in a plastic recess.

    I've had this trouble myself. When I had to get a spare key I had to get it from the dealer. They took my car reg and then produced some kind of unique 4 digit security code which was unique to my vehicle. I assume this is the same code stored within the ECU's and possibly the one you've reset with your Tech2 although I'm far from au fait with this stuff yet so I might be wrong there.

    Anyway they then had to make a chip with the right code for the spare key.

    It sounds like you're suffering something similar here as when I simply had a spare mechanical key made with a chip in it with the wrong code the car would not start although no fault codes were reported either.

    It sounds to me like you might after all the fuss you've had, have somehow lost synchronisation between your keyfob chip's code and car's security code although I might be wrong.

    It's all the help I can offer for the moment and likely I have some mis-understandings of the operation and I'd appreciate it if anyone passing could clear those up for me. I do have a professional background in industrial control systems though and general engineering also, so once I can get a better feel for how the car's security system works I'm sure I could help you.
  3. Bellaz

    Bellaz New Member

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    Many thanks for your input.

    I obtained the necessary 4 digit security code from the Vauxhall dealer at a cost of £29, it took a few days to come through.
    Using this 4 digit code, i was then able to use this code in the OP COM software in order to obtain access to reset & program the immobiliser, ECU and new key transponder.

    While reprogramming, i refreshed the measuring block status, thats when the I could see the DTC codes disappear, reappear and finally disappear once the transponder status reported correctly using the new key transponder. The old one (transponder) failed to reprogram.

    I have now purchased a fuel hand primer. I will try and fit this as close to the fuel injection pump tomorrow weather permitting. Hopefully this will eliminate any air traps stopping fuel getting to the injector pump.
  4. Bellaz

    Bellaz New Member

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    Useful note: Using the OP COM application. You can reset the ECU/Immobiliser using the 4 digit code. This is why when you buy a second hand ECU/Immobiliser you either a) have the supplier reset the unit before supplying it to you (When its in a factory reset state the unit can accept any 4 digit code at this point) or b) get the supplier to supply you the 4 digit security code of the car that the unit was removed from. When you program the ECU/Immobiliser it takes your security code and applies it and its one component that is used to sync the ECU, Immobiliser, Transponder & mechanical key to unimmobilise the car.
  5. adder_noir

    adder_noir Active Member

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    I see nice replies! Sorry this is turning into a bit of a thread hijack but it raises some interesting questions.

    1)What part does the little black standalone chip in the keyfob play? (picture pending). I know it doesn't need the keyfob circuity to be present for the car to start as I've took the central locking circuit out of my keyfob. Does the little black chip communicate directly to the engine ECU?

    2)What is the transponder you mention? Dumb one I know sorry to have to ask but I always thought the only thing the keyfob circuitry did was operate the central locking. I know this unit has to be synchronised for the central locking to work but that doesn't have anything to do with immobilisation surely or my spare key and now my main key wouldn't start my car (both do).

    3)Which parts of the car actually have the read-only memory which stores the 4 digit code? I would guess the engine ECU, injection ECU, the other ECU which I've forgotten and also the keyfob central locking circuit board. Is the immobiliser a seperate unit or is it incorporated into the engine ECU?

    4)Do all relevant parts which store the code have to be synchronised (do they all talk to each other to check they have the same code) before the car will start?

    Sorry to raise so many questions but your thread has uncovered some good information here and it would be really great for me and others who may be searching through here in the future to see it all so clearly explained.
  6. adder_noir

    adder_noir Active Member

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    [​IMG]

    [​IMG]

    [​IMG]

    That's the chip I'm on about.
  7. fronteratech

    fronteratech VXON Resident 4x4 and diesel specialist

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    Location:
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    Drives:
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    have you bleed fuel system drag fuel through pump to return using hand pump
  8. Bellaz

    Bellaz New Member

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    Cool pictures which will help others.

    1)What part does the little black standalone chip in the keyfob play? I call this the transponder. Without this your car will never start. It is used in conjunction with some circuit near the ignition barrel. Because of its proximity must be being read for the security code and other bits of information.

    2)What is the transponder you mention? This is the small black chip as highlighted in your picture. Depending on which immobiliser circuirt is used, if immobiliser 2 then you can only code the transponder (black chip) once. You can blank it and reprogram/syn the key to the immobiliser & ECU. I am not sure what other information is written to the transponder or when you reprogram you immobiliser & ECU. I guess the VIN and mechanical key reference. but I read somewhere that it was wise when buying a second hand car, if you only get supplied one key. Its best to attain another, get it cut and at the same time program the new key and reprogram the original key that way if someone was to use the old key that was not supplied it would not work even though it has the correct security code.

    Your right, the key also has the key fob module that has the central locking/deadlock remote and this works independently of circuit that is used to start the car. This can aslo be reprogrammed independently.

    3)Which parts of the car actually have the read-only memory which stores the 4 digit code? Well based on what I can see in the the OP COM software and from circuit diagrams.
    > The Transponder chip in the key (little black chip),
    > The Engine ECU,
    > The Immobiliser (which in my case Y20DTH is incorrorated with the Fuel Injector ECU on top of the fuel pump itself),

    I will double check and confirm these shortly.

    4)Do all relevant parts which store the code have to be synchronised (do they all talk to each other to check they have the same code) before the car will start? From what I understand, Yes. The Immobiliser and ECU use something called a W-Line (W stands for Wegfahrsperre, German for Immobiliser). A signal will not be transmitted from the Immbiliser to the ECU until its checked that the correct key has be inserted and turned to the on position. Once confirmed, communication is then made between the immobliser & Engine ECU before allowing the fuel to be pumped through.



    I have not had chance to insert the new one way hand pump, which I will use to prime the fuel and remove any air traps.
    I know theres a way described in the Haynes manual to prime diesel through and electronic controlled injector/pump. But it could take ages in my case as the car has be sat still for over 7 months. I tried the turn engine over for 10 second, stop and leave for 5 seconds and repeat technique but I have flatten the battery twice with no luck. I read somewhere on the internet it could take hours before the fuel is pulled through. So thats why am resorting to the oneway handpump. I will let you know how I get on shortly.
  9. adder_noir

    adder_noir Active Member

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    Wow that's an amazing reply cheers!

    Just one last thing, is the security code absolute? I see you mentioned that in some cases the chip (transponder) can only be coded once. Then I presume you have to synchronise everything else with it and that's the end of that.

    Can you get a transponder which is always re-programmable i.e. can have different codes loaded into it on demand? Wouldn't this mean that as long as you had access to a Tech2 you could basically re-program the security code for the chip and then all the ECU's & immobiliser?

    If that's the case why bother getting a code issued from the dealer? Why not just reprogram the transponder with a new one?

    What makes each chip (transponder) unique to each car?
  10. bilmeister

    bilmeister New Member

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    Location:
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    did you replace the fuel pump or use your exsisting one as you will have to get the pump ecu reset if you used a new one as your pump is programmed to your ecu causing no fuel also do you have fuel at injectors and i find a good tow start sorts out any air problems

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