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uuurgh three codes and epc light... problem after problem!

Discussion in 'A3/S3 Forum (8L Chassis)' started by JUS3IN, May 25, 2013.

  1. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
    hey all the list of problems ive had with this s3 in the 2 months ive owned it is getting silly...
    now the brakes are sorted and we've established im running a standard map im getting the epc light on! intitially i had two codes yesterday and after cleaning the trottle body and recalibrating she ran fine for half an hour then three codes... cleared them then came back ten minutes later then twice more on the way home. if i turn the engine off then on it runs fine for anything from 2 to 10 min then back on!

    [h=2]16622/P0238/000568 - Manifold Pressure/Boost Sensor (G31): Signal too High[/h] [h=4]Possible Symptoms[/h]
    • Malfunction Indicator Lamp (MIL) active
    [h=4]Possible Causes[/h]
    • Wiring/Connector(s) from/to Manifold Pressure/Boost Sensor (G31) faulty
    • Manifold Pressure/Boost Sensor (G31) faulty
    [h=4]Possible Solutions[/h]
    • Check Wiring/Connector(s) from/to Manifold Pressure/Boost Sensor (G31)
    • Check Manifold Pressure/Boost Sensor (G31)

    [h=2]16725/P0341/000833 - Camshaft Position Sensor (G40): Implausible Signal[/h] [h=4]Possible Symptoms[/h]
    • Malfunction Indicator Light (MIL) active
    [h=4]Possible Causes[/h]
    • Wiring from/to Camshaft Position Sensor (G40) faulty
    • Camshaft Position Sensor (G40) faulty
    • Timing misaligned
    [h=4]Possible Solutions[/h]
    • Check Wiring from/to Camshaft Position Sensor (G40)
    • Check Camshaft Position Sensor (G40)
    • Check Timing

    [h=2]18047/P1639/005689 - Accelerator Position Sensor 1/2 (G79/G185): Implausible Signal[/h] [h=4]Possible Symptoms[/h]
    • Malfunction Indicator Light (MIL) ON
    • Reduced Engine Output
    [h=4]Possible Causes[/h]
    • Wiring and/or connections faulty
    • Faulty ECM
    • Faulty Accelerator Pedal
    [h=4]Possible Solutions[/h]
    • Check Measuring Block Readings for Accelerator Pedal
    • Check Voltage Signals from ECM to Throttle Pedal (see factory repair manual)
    • Check Wiring and Connectors from ECM to Accelerator Pedal
    [h=4]Special Notes[/h]
    • There are 2 sensors in the accelerator pedal, both should increase in the same direction as the accelerator is pressed but they have different scales. This means one counts from 0 to 100, while the other one counts from 0 to 50.

    • Accelerator Position Sensor faults can be caused by issues with the Oxygen Sensor(s) and it's wiring. Please verify this BEFORE replacing the ECM or Accelerator Pedal. Accelerator Pedal failure is very rare.

    these must all be linked somewhere... surely, any common problems that are likely to throw all three codes?
    also wondering if my v3 relentless has caused damage to the lambda wireing after that last bit on the accelerator code!?
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  3. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
    are these all earthed together? also could one going cause the other two too show faulty? cant believe all three have failed on the same day, search through the posts on here and cant find any with the same three codes? im thinking it must be a wireing issue or water in the ecu, was raining hard all day yesterday, is the ecu in that white box near the wiper mechanism?
    #2
  4. 16Klappe
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    16Klappe Princess Clap.

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    [May 25, 2013]
    MAAAAAAAAAAAAAFFFFFFFFFFF SSSSSSSSSEEEEEEENNNNNNSSSSSSOOOOOORRRRRRRR.
    #3
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  5. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
    love you klappe!? guess your pretty sure then?
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  6. 16Klappe
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    16Klappe Princess Clap.

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    [May 25, 2013]
    Disconnect the MAF, reset the fault codes, take it for a drive.

    If only the EPC light stays on and you get a MAF code I would be mightily confident. When the MAF is disconnected or has totally failed the EPC light comes on and the car resorts to a preset table of control based against the rpm rather than the constant adaptions it would normally make. Perfectly safe to drive with the MAF disconnected in most cases.
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  7. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [May 25, 2013]
    ecu lives in scuttle to the right of centre as looking at it.. not the white box no.
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  8. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [May 25, 2013]
    his code is>> 16622/P0238/000568 - Manifold Pressure/Boost Sensor (G31): Signal too High


    MAP sensor... not MAF

    Is this how you read it dude?
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  9. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
    yeah thats right, also made no difference with maf disconnected ecp still came on... cleaned the maf and after it dried ran for 5 miles ok before throwing the manifold one and throttle one again?
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  10. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
    erm i think it said pressure too high intermittant? just cleared them again and parked her up behind the two farm gates i have to go through, think that makes it worse keep undoing the darn gates lol....
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  11. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
    how does the scuttle come off, i dont want to break it? guessing wipers off then pull some hiden clips upwards?

    gotta be worth a look right?
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  12. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
    also had all three codes plus maf and engine speed sensor no signal aswell with the maf disconnected!?
    after that when i reconnected and wiped she ran for 5 miles ok?
    #11
  13. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
    you saying map sensor could be the cause of all this bill? just got the ecu plugs off an wd40'd em... lost a bloody wiper cap, flew off at 1000mph somewhere, doh!
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  14. 16Klappe
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    16Klappe Princess Clap.

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    [May 25, 2013]
    You have got a hardware issue somewhere, potentially MAP sensor then.

    As far as I am aware there is no way around diagnosing a faulty MAP sensor other than replacing it, with it unplugged **** just gets ****ed up and the car will kangaroo and drive lumpy. If it isn't the MAF as I suggested then you really need to talk to a specialist and have the car logged and a fault finding session. MAF sensors cause a lot of the problems you have mentioned, past the MAF there isn't really any suggestion which can be made reliably.

    There isn't a perfect 1.8t in the land, every single one has a slight boost leak, an under reading MAF or whatever else. Don't let it get you down.
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  15. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
    i guess we're stuck then.... so the map sensor could cause the throttle position code aswell?

    where is the map sensor, is it the little one near the throttle body on the front? whats its name g31 sensor?
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  16. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [May 25, 2013]
    no I did'nt say that

    for multiple sensors to all have issues at same time its most likely electrical, earth connection, power, fuse gone etc etc..
    several earths terminate under and around battery area..

    you need a wiring diagram to know whats shared between these sensors etc
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  17. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
    cheers bill, where are the fuses... also i did notice sometime the epc was coming on when i turned right so maybe earth is a good shout...

    i clean the ecu connectors just now pluged her all back in, got about 4 more codes and she was running worse than ever, the throttle peddle wasnt doing a thing and the revs were hunting around 1100rpm and the car sounded like a bag of bolts.....! not good, disconnected the battery and tapped the negative a few times now she's purring like a kitted with no codes!!?

    odd one, must be earth surely
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  18. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
    would like to add to this, when the car was running lumpy and the throttle wasnt working i deleted the codes and then my vcds flashed up as disconnected came back then read no fault codes while it was running like that for a couple of minutes so im guessing the ecu lost power?

    another thing ive noticed today my electric windows work but the click to go right up or right down dont work???

    i had the battery out half hour ago, removed, cleaned and refitted all earths i could see. i removed the panel in the drivers footwell and fuse box and the carpet where the bonnet catch is looking for any obvious faults,,, none found. checked the fuses, all ok.

    be back out there tomorrow, if anyone has any suggestions please post up... did wonder about the battery or ecu being faulty?
    #17
  19. Vex182
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    Vex182 Guess what I drive...

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    [May 25, 2013]
    To make the one click windows work, when they are both closed, hold the left window button up towards closed for 3 seconds then the right for 3 seconds, then when you press down on either, it should drop as normal.
    #18
  20. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
    cheers vex
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  21. JUS3IN
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    JUS3IN silver sleeper

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    [May 25, 2013]
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  22. JUS3IN
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    JUS3IN silver sleeper

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    [May 26, 2013]
    ok im gonna rule out fuse after checking them all, inc the one under the dash... im thinking because they are intermittant its either a break in a wire or an earth... or a sensor failing. if its the map sensor failing i think its my fault, when i refitted my turbo i slightly overfilled and she's spat oil through the tip and intercooler pipes, its pretty oily in there. tryed to get the map of yesterday for cleaning and dropped the little screw driver bit dow behind the headlight into the abyss!

    also as i wrote in my last post i was messing around near the map sensor the other day trying to find a place for the pipe i removed from the airbox when fitting the s2000 filter, so i could easily have broken one of the wires...

    think i need a voltmeter today, sounds fun eh!

    does anyone know where the map and other said sensors (camshaft, engine speed, throttle position) share an earth?
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  23. JUS3IN
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    JUS3IN silver sleeper

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    [May 26, 2013]
    whatever ive done its been fine today??? touch wood this isnt a recurring problem....
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