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Brake lights constantly on

Discussion in 'Audi S4/A4/A4 Cab (B7 Chassis)' started by bugwhizz, Nov 21, 2009.

  1. bugwhizz
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    bugwhizz Member

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    [Nov 21, 2009]
    Hi all, been floating about for a while now and used plenty of the good advice thats on offer on this site but here's a problem i've been having and it doesnt seem to want to go away.

    The symptoms are as follows:-

    flashing heater plug light
    esp/abs light on
    brake lights on
    car runs in limp mode ie no boost

    The car is a 2005 8e chassis 3lt v6 tdi sportline Quattro.

    Having read up on the forum with the search option i replaced the brake light switch for the newer upgraded brake switch, this did not fix the problem, so for the sake of another £8 i bought another just to prove the switch wasnt at fault.

    Faults can be cleared down with vcds but as soon as the car is driven they all come back but the brake lights stay on constantly, the brake light test in the live reading section shows the brake light switch to be operating correctly.

    I assume that with the brake lights on there will be a signal inhibiting engine performance??, this would explain the limp mode/lack of boost?

    With the ABS unit under the bonnet unplugged the brake lights are still on so i'm guessing this removes the ABS from the equation, please bear in mind i'm quite new to all this new stuff, i've had passats for years and never had one miss a beat, change to an Audi and nothing but problems, little upset to be honest, anyways, back on track.

    I've heard that the central electrics unit has a large part to play in the cars electrics, is there any way to test the unit before replacing??,(8E0907279K is the pt number) once it's unplugged the brake lights go out?? so i would hope it would be that??, failing that i'm going to be looking at wiring.

    Any help or direction on the subject would be much appreciated.

    Also, where's the best place to get vcds from??, anywhere in the UK or is it direct from Ross tech?

    Cheers all
    Graeme
    Last edited: Nov 21, 2009
    #1
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  3. 1wheelonly
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    1wheelonly cabriolet VCDS Map User

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    [Nov 21, 2009]
    regarding vcds, pm a member named " NHN " he'll sort you out, he supplies everyone on here, there all the latest and brand new and genuine, exactly as youd buy from ross-tech, you wont get it cheaper either.
    #2
  4. bugwhizz
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    bugwhizz Member

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    [Nov 22, 2009]
    cheers for the help on the vcds fella.

    Has no-one got any ideas on the current fault??.

    Just bought a 2nd hand central electrics unit from a sheffield breaker so i'll be swapping that out on monday all being well.
    #3
  5. bugwhizz
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    bugwhizz Member

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    [Nov 23, 2009]
    well.today i swapped the central electrics unit for a 2nd hand one, no joy, all faults still there and brake lights still on constantly with the ignition on.

    I guess the unit needs to be coded to the car, will have to sort that tomorrow at the vag specialists.

    Anyone any experience of this fault before , or anyone who may have a dircetion to start in??

    Graeme
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  6. bugwhizz
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    bugwhizz Member

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    [Nov 28, 2009]
    well, the central electrics unit was coded in and made no difference!!, so the VAG specialists continuity checked the wiring to the rear brake lights for faults and all was well in that area, they didnt charge me for the 2 days they spent trying to fix the car which was a huge bonus as that puts me back at square one, costwise.

    I'm beginning to think this is going to cost me a fortune now as it is seriously looking like it's gonna have to go to the dealers!! and that means £87 + vat per hour!, my doctor doesnt even get that much!!

    I now own vcds so i'm going to try and paste some logs up to see if anyone can help further
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  7. markyzs180
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    markyzs180 Member

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    [Nov 28, 2009]
    my local audi dealer is 120 + vat !!! surely the vagspecialist found some faults? can't beleive you've got a dash like a xmas tree with no error codes?
    #6
  8. bugwhizz
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    bugwhizz Member

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    [Nov 30, 2009]
    Well, after recieving my lead from NHN, thanks fella!!, i did a complete scan with the vcds, the results are as follows, copied and pasted, the car is now in with another "specialist" in leeds.

    Monday,30,November,2009,10:00:25:26223
    VCDS Version: Release 908.1

    Address 01: Engine Labels: Redir Fail!
    Control Module Part Number: 8E0 910 401 K HW: 8E0 907 401 AJ
    Component and/or Version: 3.0L V6TDI 000SG 0030
    Software Coding: 0011911
    Work Shop Code: WSC 06335 000 00000
    8 Faults Found:

    012696 - Control Circuit for Intake Manifold Runner (Bank1): Implausible Signal
    P3198 - 002 - Lower Limit Exceeded
    Freeze Frame:
    Fault Status: 01100010
    Fault Priority: 0
    Fault Frequency: 1
    Time Indication: 0

    Freeze Frame:
    RPM: 0 /min
    Torque: 296.4 Nm
    Speed: 0.0 km/h
    Voltage: 11.86 V
    Duty Cycle: 0.4 %
    Duty Cycle: 0.4 %
    Duty Cycle: 0.4 %

    012697 - Control Circuit for Intake Manifold Runner (Bank2): Implausible Signal
    P3199 - 002 - Lower Limit Exceeded
    Freeze Frame:
    Fault Status: 01100010
    Fault Priority: 0
    Fault Frequency: 1
    Time Indication: 0

    Freeze Frame:
    RPM: 0 /min
    Torque: 296.4 Nm
    Speed: 0.0 km/h
    Voltage: 11.86 V
    Duty Cycle: 0.4 %
    Duty Cycle: 0.4 %
    Duty Cycle: 0.4 %

    005121 - EGR Valve (N18): Short to Ground
    P1401 - 001 - Upper Limit Exceeded
    Freeze Frame:
    Fault Status: 01100001
    Fault Priority: 0
    Fault Frequency: 1
    Time Indication: 0

    Freeze Frame:
    RPM: 0 /min
    Torque: 296.4 Nm
    Speed: 0.0 km/h
    Voltage: 11.86 V
    Duty Cycle: 94.3 %
    Mass Air / Rev.: 0.0 mg/str
    Mass Air / Rev.: 0.0 mg/str

    012867 - Control Circuit for Throttle Body Module: Electrical Malfunction
    P3243 - 002 - Lower Limit Exceeded
    Freeze Frame:
    Fault Status: 01100010
    Fault Priority: 0
    Fault Frequency: 1
    Time Indication: 0

    Freeze Frame:
    RPM: 0 /min
    Torque: 296.4 Nm
    Speed: 0.0 km/h
    Voltage: 11.86 V
    Duty Cycle: 92.7 %
    Bin. Bits: 010
    Mass Air / Rev.: 0.0 mg/str

    013128 - Control Circuit for Controller for Turbocharger 1 (J724): Electrical Malfunction
    P3348 - 008 - Implausible Signal
    Freeze Frame:
    Fault Status: 01101000
    Fault Priority: 0
    Fault Frequency: 1
    Time Indication: 0

    Freeze Frame:
    RPM: 0 /min
    Torque: 296.4 Nm
    Speed: 0.0 km/h
    Temperature: 0.9°C
    Duty Cycle: 80.9 %
    Voltage: 11.86 V
    Duty Cycle: 0.4 %

    008200 - Intake Manifold Flap; Bank 1: Electrical Malfunction
    P2008 - 001 - Upper Limit Exceeded - Intermittent
    Freeze Frame:
    Fault Status: 00100001
    Fault Priority: 0
    Fault Frequency: 1
    Time Indication: 0

    Freeze Frame:
    RPM: 0 /min
    Torque: 296.4 Nm
    Speed: 0.0 km/h
    Voltage: 11.93 V
    Duty Cycle: 0.4 %
    Duty Cycle: 0.4 %
    Duty Cycle: 0.4 %

    013128 - Control Circuit for Controller for Turbocharger 1 (J724): Electrical Malfunction
    P3348 - 003 - Mechanical Failure - Intermittent
    Freeze Frame:
    Fault Status: 01101000
    Fault Priority: 0
    Fault Frequency: 1
    Time Indication: 0

    Freeze Frame:
    RPM: 0 /min
    Torque: 296.4 Nm
    Speed: 0.0 km/h
    Temperature: 0.9°C
    Duty Cycle: 80.9 %
    Voltage: 11.86 V
    Duty Cycle: 0.4 %

    013128 - Control Circuit for Controller for Turbocharger 1 (J724): Electrical Malfunction
    P3348 - 002 - Lower Limit Exceeded - MIL ON
    Freeze Frame:
    Fault Status: 01101000
    Fault Priority: 0
    Fault Frequency: 1
    Time Indication: 0

    Freeze Frame:
    RPM: 0 /min
    Torque: 296.4 Nm
    Speed: 0.0 km/h
    Temperature: 0.9°C
    Duty Cycle: 80.9 %
    Voltage: 11.86 V
    Duty Cycle: 0.4 %


    Readiness: 0 0 1 1 1


    From what i can see and from what i've read up on, the brake light switch being inop would cause many of the faults listed below??, thing is, 3 different people have tried fitting 3 different switches??

    Any help would be much appreciated.
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  9. bugwhizz
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    bugwhizz Member

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    [Dec 2, 2009]
    Hi all

    the VAG specialist came throught with a result!!!, turns out there was a broken wire between the brake light switch and the engine ECU, this broken wire also supplies a live to the ESP and ABS so thats why those dash icons were lit also.

    He said the brake light switch tells the engine ECU to switch the brake lights on which in turn sends a signal via CANBUS to the central electrics unit which then turns the brake lights on!!.

    Sounds like a long drawn out, over complicated affair but it's now repaired and all the faults have cleared down and not reappeared so all is well.

    The VAG specialists name is Pete Jordan and he's based in leeds, got to say i'm very impressed with him so far!!, i'll pm numbers to anyone who wishes to use him for servicing and repairs etc.

    Graeme
    Last edited: Dec 2, 2009
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  10. ianysm
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    ianysm Active Member

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    [Jan 21, 2010]
    Result!
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  11. blobby
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    blobby New Member

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    [Nov 19, 2010]
    can you msg me the chaps number if you could be so kind i have excactly the same fault on my audi a4
    thx
    blobby
    #10

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