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Thread: ZEE Falure ? - CAN Bus Errors - Yellow ESP Light ON, revs cut, clutch disengaged

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  1. #1
    Join Date
    Feb 2014

    Cool ZEE Falure ? - CAN Bus Errors - Yellow ESP Light ON, revs cut, clutch disengaged

    Hi Everyone,

    Any help on this fault, would be gratefully received.

    It's a 450 cabrio mid 2000 edition, with the old gear-stick (golf-ball) and a ZEE unit. 87kkm LHD.


    About a year ago, it started doing the following, while driving;

    Yellow ESP light goes hard on and stays on.
    Engine cuts to 1000 rpm.
    Clutch disengages.
    No other warning lights.
    Pressing accelerator has no effect.

    Pull over. Stop. Switch off engine. Restart engine and all is well.

    This fault occurred randomly, with weeks or months between events. However, gradually the frequency increased until finally, one could start the car, leave it ticking over and 30 seconds later the fault occurred having not moved the car or placed it in gear.

    Furthermore, with a poorly charged battery the fault occurs almost immediately, and if the revs. fall with a poor battery fitted.

    My attempts at Corrective Action:

    I have;

    Changed the battery (new).
    Checked and refitted the Earth straps in Engine bay and battery compartment.
    Changed the Brake pedal switch (with new unit).
    Changed the Lateral Accelerometer (with 2nd hand unit).
    Checked the cables and connectors to the instrument panel.
    Checked the multi-connector to the ZEE.


    After much head scratching and interpretation of the circuit diagrams on a copy of WIS, I determined that there are 4 units which communicate via a CAN bus with each other;

    Instrument Panel
    Central Electronics Unit (ZEE)
    Engine ECU (MEG)
    ABS ECU (Bosch ABS controller)

    Sadly, the CAN bus does not speak to the outside World. As this car was made just prior to the Jan 1st 2001 EU Directive on OBD-II it seems the sole way to communicate with it is via proprietary use of pins on the OBD connector and a Mercedes box.

    So, I ordered up a STAR C3 and hard drive for a Dell D630 laptop, from our Asian friends, it has the release date 07/13.

    And here are the results of the runners and riders, codes;

    On the N10 (Central Electronics) = ZEE

    B1000 - General internal control unit hardware fault
    B1030 - Immobilizer counter overflow or CAN communication is faulty
    B1016 - CAN message 'Diagnosis' from instrument cluster is missing
    B1010 - Status 'Fault' of CAN controller
    B1014 - No CAN message from control unit N3/10 (MEG motor electronics control unit)
    B1015 - CAN message 'Kilometre reading' from instrument cluster is missing.
    B1400 - Left turn signal lamp defective
    B1111 - Unlocking operation failed due to short circuit

    N47-7 (ABS Control Module):

    C1025 - CAN bus signal No CAN message from control unit N10 (Central Electronics).
    C1025 - CAN bus signal No CAN message from control unit N3/10 (MEG motor electronics control unit).
    C1104 - B24/2 (Lateral acceleration sensor).

    N3/10 (MEG motor electronics control unit):

    39 - B24/2 (Lateral acceleration sensor)
    46 - Load fault in monitoring module

    The instrument cluster unit and the restraint system unit, have no faults listed.

    I have not cleared/erased any codes, I am tad unimpressed that there is no time/date stamp on the stored codes !

    In my initial primitive fault-finding efforts, I did disconnect the lateral acceleration sensor, so that's the stored code.

    The car is always garaged and there is no obvious water ingress in any of the connectors, even the lateral acceleration sensor was pretty clean.

    My best guess:

    SO.... I reckon it's the N10/Central Electronics/ZEE and precisely the CAN bus Controller chipset therein.

    BUT..... why does it work at all ?

    I am an electronics engineer by training, and in my world when a chip fails, it fails, so I find it odd that a CAN bus controller can fail after a period of time, yet work after a reset.

    I am about to extract the ZEE PCB module and carefully open it up to check the electrolytic capacitor on the board, which I am guessing is across the 12v rail or internal voltage regulator.

    If I have to replace the ZEE unit, the STAR software (XENTRY-DAS) is saying "Special function 'Immobilizer' must be performed after exchanging control unit N10 (Central Electronics)"

    I have a nasty feeling that this 'special function' will require a "TAN Code" pin-code and therein lies another issue.

    Also, I am concerned that the alarm-immobiliser key-fobs will need to be 'teached-in' if the ZEE is changed.

    Has anyone had direct experience of changing a ZEE and if one can obtain a 'clean' or re-manufactured ZEE which can assume the identity of the failed unit ?

    You will notice I have studiously avoided involving a Mercedes Stealer, thus far.

    Cheers, and thanks for your input.


  2. #2
    Join Date
    Nov 2007
    I had a Smart with those symptoms about two years ago. Replacing lateral acceleration sensor sorted it. On inspection I found the potting compound had cracked allowing water into the sensor. I dried out the sensor and I use it now as an acceleration sensor for balancing rotating machinery:

    CAN bus faults seem to be the norm on Smarts with Zee units. Mine always exhibits a long list but they go away for awhile when erased.
    Drives a Smart Cdi - 65 to 85 MPG

  3. #3
    Join Date
    Mar 2012
    If it was me, I'd clear the error code history (lower case 'f') and retest to see current/active errors (upper case'F') to narrow down the search.

    If your car has a rev counter, I'd start there - there's sometimes a module on the green connector and short lead which can break internally causing can bus errors - I think you can remove this module as it has male and female on each end of the lead and plug the loom directly to the rev counter.

    TAN code generator is easy to get hold of - great for re-synchronising keys to car, activating paddle shift steering wheel etc etc
    Last edited by bob-in-dav; 11-02-2014 at 07:03 PM.

  4. #4
    Join Date
    Mar 2010
    I personally think the CANBUS errors are a red herring and that your issue is more basic than that. When our old zee-equipped car exhibited the same issue it was traced to being turbo boost related.

    So the issue on ours was either failing turbo, cracked manifold or (experience now tells me is more likely) a failing cycle valve, which on the later 700cc will out the car into a "mild" safe mode (reduced power by cutting the turbo) but on the earlier 600cc cars would create a hard-safe mode - cut power completely and flash up the ESP light. Which is what you have.

    Try changing the cycle valve before doing anything else. It's a 15 part (or thereabouts) - and it may be the root cause of your problem.
    2004 Roadster-Coupe SB2 Brabus
    2005 ForTwo Brabus Numeric
    2014 Skoda Yeti 4x4 DSG
    ex 2002 City Coupe 600cc Pulse
    ex 2003 City Coupe 700cc Passion

  5. #5
    Join Date
    Mar 2012
    Just found an old thread with photo of what I mentioned in the previous response -

  6. #6
    Join Date
    Jun 2005
    Bristol, , United Kingdom
    And also disconnect the MAP sensor to see if that cures it.

    Living life with Pure Passion, always with my finger on the Pulse

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