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  • avatar bpeebles 06/27/10 9:13 pm PST

    Although the info above is helpful in isolating your communicataions thing, I strongly suspect that it will not fix your starting issue. I would suggest you use ( http://www.ross-tech.com/vag-com/ )
    to troubleshoot that problem. I have a VagCom myself and most shops use VagCom too.

    To address your starting problem... When a VW starts then immedeatly stalls, this is usually caused by the "immobilizer" kicking in.

    The "immobilizer" is a security device that senses if the key used to start the engine is 'coded' correctly for the vehicle. (There is a 'chip' in the keyfob that communicates with the dashboard.)

    The first thing you should try is to use ALL 3 of the keys that came with the vehcile (2 keyfobs and 1 valet key) Determine if the starting issue happens with all of the keys or just one if them.

    If just 1 key, then that specific key needs to be re-programmed into the onbaord computer.

    If happens with all 3 keys, then suspect the sensor which surounds the ignition-switch is not reading the keys reliably.

    Source: personal experince

Answers

  • MrShift@Edmunds 06/24/10 11:43 am PST

    Terminal Resistance For CAN-Bus, Checking

    Function
    The Engine Control Module (ECM) communicates with all databus-capable control modules via a CAN databus.

    These databus-capable control modules are connected via two data bus wires which are twisted together (CAN_High and CAN_Low), and exchange information (messages). Missing information on the databus is recognized as a malfunction and stored.

    Trouble-free operation of the CAN-Bus requires that it have a terminal resistance. This central terminal resistor is located in the Engine Control Module (ECM).

    Recommended special tools and equipment

    • V.A.G 1526 multimeter or V.A.G 1715 multimeter
    • V.A.G 1594 connector test kit
    • Wiring diagram

    Test requirements

    • A CAN-Bus malfunction was recognized via On Board Diagnostic (OBD). Diagnostic mode 3: Check DTC memory.
    • Ignition switched off.

    Test sequence

    • Connect test box to Engine Control Module (ECM). connect test box for wiring test. During this, wiring harness to Engine Control Module (ECM) is not connected.
    • Check the central termination resistor in the Engine Control Module (ECM):
    • To do this, measure resistance between test box socket 58 + 60:

    Specified value: 60.0 to 72.0 Ohms

    If resistance value is not in specified range:

    • Replace Motronic Engine Control Module (ECM) -J220-.

    If resistance value is in specified range:

    • Disconnect test box harness connector from Engine Control Module (ECM).
    • Connect test box to control module wiring harness.
    • Check CAN data bus wires for shorts among one another:
    • To do this, perform a resistance measurement between test box sockets 58 + 60:

    Specified value: Infinite Ohms

    If specified value is obtained (wires have no shorts):

    • Eliminate malfunction in Data-Bus wires or in other Data-Bus components according to wiring diagram.



  • bpeebles 06/27/10 9:13 pm PST

    Although the info above is helpful in isolating your communicataions thing, I strongly suspect that it will not fix your starting issue. I would suggest you use ( http://www.ross-tech.com/vag-com/ )
    to troubleshoot that problem. I have a VagCom myself and most shops use VagCom too.

    To address your starting problem... When a VW starts then immedeatly stalls, this is usually caused by the "immobilizer" kicking in.

    The "immobilizer" is a security device that senses if the key used to start the engine is 'coded' correctly for the vehicle. (There is a 'chip' in the keyfob that communicates with the dashboard.)

    The first thing you should try is to use ALL 3 of the keys that came with the vehcile (2 keyfobs and 1 valet key) Determine if the starting issue happens with all of the keys or just one if them.

    If just 1 key, then that specific key needs to be re-programmed into the onbaord computer.

    If happens with all 3 keys, then suspect the sensor which surounds the ignition-switch is not reading the keys reliably.

    Source: personal experince

  • Stever@Edmunds 06/29/10 12:30 pm PST

    You can reply in this thread by clicking the Answer this Question button and that will help keep all the information in one spot. Thanks!

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