Engine warning light

Discussion in 'General Motoring' started by Benny, Aug 3, 2004.

  1. Benny

    Benny Guest

    Does anyone know why my engine light comes on when I'm driving my
    Vectra 2ltr diesel, but then goes off if i even slightly touch my
    brake pedal?
    Anyone who can help me, as my Haynes manual has been no help.
    Thank you.
    Benny
     
    Benny, Aug 3, 2004
    #1
  2. Benny

    malc Guest

    What year is it?
    If pin 6 of the diagnostic socket is engaged, flash codes can be retrieved.
    link to pulling codes:
    http://forums.delphiforums.com/cartune/messages?msg=28.1
     
    malc, Aug 4, 2004
    #2
  3. Benny

    Equalizer Guest

    I would be really interested to know the answer to that one
    since my problem developed in the same way.
    I have a 1999 Vectra diesel and when the engine management
    light used to come on whilst driving it would extinguish
    upon a light touch of the brake pedal. Not anymore.
    After 9 months of this the light now comes on every few
    minutes of driving accompanied by a dramatic reduction in
    engine power.

    The car is now virtually undriveable for more than a few
    miles at a time. I am going to try and pull the code/s by the
    method that has been described elsewhere on this very useful
    forum. Would still appreciate any other advice
     
    Equalizer, Aug 5, 2004
    #3
  4. Benny

    mike Guest

    well it's something pretty serious for hte car to go into 'get you home'
    mode.
    pull the codes & let us know

    mike
     
    mike, Aug 5, 2004
    #4
  5. Benny

    Equalizer Guest

    If I get a chance I'll have a go tomorrow. I hope it's not
    something serious. Since the problem has been quite
    bad I've still driven the car from London to Cornwall
    twice, used it every day and down to Dorset last Saturday
    from Kent. The car will get up to 80mph after about 2
    minutes, foot flat to the floor, but the light constantly
    comes on and goes off during any journey, with a loss
    of power. If I allow the revs to drop to around 1500 the
    light goes out immediately but comes back on again
    past 50mph or during hard acceleration. A real pain
    which draws regular abuse from other drivers who
    think " that arsehole in front keeps slowing down for
    no reason". I was following behind a dustcart the other
    day but even that got away from me!
     
    Equalizer, Aug 5, 2004
    #5
  6. Benny

    kevin Guest

    had the same problem, it turned out to be the air flow sensor, on the
    intake pipe near the air filter, just two screws and a wiring plug to fit, I
    had the car put on all the testing gear first and it said it was a different
    problem which cost £200. before they found the right thing, hope this
    helps,( the part is about £100 sorry) it was a different car to drive
    straight away
     
    kevin, Aug 5, 2004
    #6
  7. Benny

    Windy Guest

    If it goes off when the brake is applied then it is due to bad adjustment of
    the brakelight switch. on a diesel the switch is double poled (one set of
    contacts on and one off) if the switch is badly adjusted ECU fault codes
    this and limp home mode results.

    To cure fault drop the cover off above the pedals (three large black plastic
    screws) press down on brake pedal and pull switch pin down with pointed nose
    pliers release pedal (switch will then ratchet back to correct position) If
    fault is still present then switch may be u/s and need replacing


    Steve
     
    Windy, Aug 5, 2004
    #7
  8. Benny

    Equalizer Guest

    This is greatly appreciated, Steve. I'll check this one out
    tomorrow. I tried to pull the codes today with a paperclip
    but the management light would not flash. It just went out
    as normal, a couple of seconds after the ignition was
    switched on.
    Checked the terminals on the 16pin socket down by the
    handbrake under a plastic cover. Found only number 1
    terminal to be live (ignition on or off) found 2 other
    terminals, 14 and 15 I think, were earth wires, the others
    didn't appear to be either earths or lives?
    There is nothing connected in the number 6 pin but
    there is a wire connection running to the number 5
    terminal however, grounding that one to earth with
    the ignition switched on/off caused nothing at all to
    happen.
    Anyone know what I am overlooking here?
     
    Equalizer, Aug 6, 2004
    #8
  9. Benny

    Equalizer Guest

    Thanks for this. I took the sensor out today and had
    a look. It appears to be a fairly basic wire probe in
    a sealed plastic case. I wouldn't know how to test it.
    I noticed that it's labeled "Bosch" a sort of engineering
    "designer label" these days, commonly used to justify rip-off
    prices, so £100 for a short piece of wire in moulded plasic
    which might originate from China, sounds par for the course.
    This is why I am trying to sort out the problem myself.
     
    Equalizer, Aug 6, 2004
    #9
  10. Benny

    malc Guest

    Under no circumstances should the other terminals be probed. If pin 6 is
    vacant, a later protocol (EOBD) is used for diagnostics, which requires a
    scan tool. All later vehicles are protocoled to EOBD (European on board
    diagnostics) with upto 4 possibilities on format. The good news is, there
    will soon be an inexpensive reader available on the UK market, allowing
    DIYers to read their own codes. One such product is called Autotap, which
    plugs in to a laptop.
     
    malc, Aug 6, 2004
    #10
  11. Benny

    Equalizer Guest

    ........cut additional very useful information

    Thankyou for your reply. As a result I have now found
    an auto-electrical diagnostic centre in Bexleyheath Kent
    which has agreed to read the code/s for me on Monday
    for £20, which is about half of what most others charge.
    I will post back with the fault diagnosis which might be
    useful to others in the future.
     
    Equalizer, Aug 7, 2004
    #11
  12. Benny

    malc Guest

    Sensible idea.
    Please ask them for all the powetrain codes and post them back to us, as a
    particular code doesn't necessarily mean it's component is faulty,
    especially if more than one code is present.
     
    malc, Aug 7, 2004
    #12
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