Help I have Electrical Gremlins ESP issue

[techfreak]

Anyone have the alternator wiring diagram for a 3.0tdi BMK and/or engine wiring diagrams please? or can someone come up with something that could be linked that is causing the intermittent load signal faults in the auto trans and abs modules?

The problem is this:-

I have an intermittent esp fault - drive for a few minutes - sometimes longer and the esp warning refer to manual pops up.

The light goes out straight away and this will happen on every first journey. If I stop the car after about 5/10 mins of driving and restart the fault doesn't come back. If the car is left for longer i.e. a few hours/overnight - it happens again.

On occasion the esp warning lamp stays lit - until the car is switched off again.

Before this happens the esp button will turn off ASR at first press, and turn off ESP if held down for longer i.e. works as it should. After the fault appears the esp button will not turn ASR off, press the button and the esp light, lights up but then immediately goes out. Hold it for longer and it will turn off ESP illuminating the light on the dash.

I believe even when the light goes out or the fault hasn't come up the ASR is not working as I chucked it round a bend in the wet and there was definite slipping but no ASR kicking in and no esp light flickering.

So far I have changed the brake light switch. I didn't think it was this but for the cost it was worth a shot.

This is the vcds reading:

Address 02: Auto Trans        Labels: 09L-927-760.lbl   Part No SW: 4F0 910 156 H    HW: 09L 927 156 
   Component: AG6 09L 3.0lTDI RdW 0080  
   Revision: --H01---    Serial number:        0040400
   Coding: 0000001
   Shop #: WSC 02335 785 00200
   VCID: 2855E6799BE83A9


1 Fault Found:
18265 - Load Signal 
            P1857 - 000 - Error Message from ECU - Intermittent
             Freeze Frame:
                    Fault Status: 00110000
                    Fault Priority: 0
                    Fault Frequency: 4
                    Reset counter: 40
                    Mileage: 160218 km
                    Time Indication: 0
                    Date: 2013.05.14
                    Time: 19:32:49


             Freeze Frame:
                    RPM: 800 /min
                    RPM: 768 /min
                    RPM: 0 /min
                    (no units): 30.0
                    (no units): 23.0
                    Temperature: 32.0°C
                    T.B. Angle: 0.0°

-------------------------------------------------------------------------------
Address 03: ABS Brakes        Labels: 4F0-910-517.lbl
   Part No SW: 4F0 910 517 E    HW: 4F0 614 517 A
   Component: ESP8 quattro    H03 0010  
   Revision: 00000000    Serial number: 00000000000000
   Coding: 0004492
   Shop #: WSC 02335 785 00200
   VCID: 2649E84191FC2C9


1 Fault Found:
18265 - Load Signal 
            P1857 - 000 - Error Message from ECU - Intermittent
             Freeze Frame:
                    Fault Status: 00100000
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 60
                    Mileage: 160218 km
                    Time Indication: 0
                    Date: 2013.05.14
                    Time: 19:32:48


             Freeze Frame:
                    Hex Value: 0x0280
                    Hex Value: 0x40A2
                    Hex Value: 0x0000
                    Hex Value: 0x00AC
                    Hex Value: 0x00FF

-------------------------------------------------------------------------------
Address 08: Auto HVAC        Labels: 4F0-910-043.lbl
   Part No SW: 4F0 910 043     HW: 4F2 820 043 B
   Component: KLIMABETAETIGUNGH11 0100  
   Revision: 00000022    Serial number: 00000000036552
   Coding: 0001046
   Shop #: WSC 02335 785 00200
   VCID: DBBF09B51A3E211


2 Faults Found:
00256 - A/C Pressure/Temperature Sensor (G395) 
            002 - Lower Limit Exceeded - Intermittent
             Freeze Frame:
                    Fault Status: 00100010
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 59
                    Mileage: 160198 km
                    Time Indication: 0
                    Date: 2013.05.14
                    Time: 13:01:02


01314 - Engine Control Module 
            008 - Implausible Signal - Intermittent
             Freeze Frame:
                    Fault Status: 00101000
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 59
                    Mileage: 160219 km
                    Time Indication: 0
                    Date: 2013.05.14
                    Time: 19:35:33

-------------------------------------------------------------------------------
Address 46: Central Conv.        Labels: 4F0-910-289.lbl
   Part No SW: 4F0 910 289 E    HW: 4F0 907 289 E
   Component: Komfortgeraet   H14 0090  
   Revision: 00900014    Serial number: 01000491320000
   Coding: 0008435
   Shop #: WSC 00137 211 56823
   VCID: 2C5D1A698F10169


   Part No: 1K0 951 605 A
   Component: LIN BACKUP HORN H01 1201


   Part No: 4F0 910 177 
   Component: Innenraumueberw.H01 0010


1 Fault Found:
01134 - Alarm Horn (H12) 
            012 - Electrical Fault in Circuit
             Freeze Frame:
                    Fault Status: 01101100
                    Fault Priority: 3
                    Fault Frequency: 254
                    Reset counter: 20
                    Mileage: 158953 km
                    Time Indication: 0
                    Date: 2013.03.21
                    Time: 12:10:49

I will be changing the a/c pressure sensor this weekend hopefully, I had at look at trying to do it with the bumper in place and it looks too fiddly so will do it with bumper off.
The alarm fault also never clears even though the alarm works.

from my reading and searching it appears to be alternator wiring harness or a grounding issue.... anyone got any other clues?

this is what tells me it could be alternator wiring:

ESP Light turns on after about 15min - TDIClub Forums

How to: Fix broken Load Signal cable from Alternator - SEAT Cupra.net - SEAT Forum

How I fixed fault code 17911 - TDIClub Forums

[gupsterg]

Concerning this ....

00256 - A/C Pressure/Temperature Sensor (G395) 002 - Lower Limit Exceeded - Intermittent

I know on another thread I said sensor could be at fault... but it could be something else as well ... Link:- Air Con not working...advice please

Chadders had a regas 1st, then changed sensor, still has fault ... he has new compressor for sale ...

In chronological order :-

His regas thread Link:- Aircon issue problem or not??

His fault scan Link:- Aircon problem found on scan

His sensor change/compressor Link:- Air con ECON problem

You may need to look at MVB's or get some proper diags done for AC ...

[MarkTM]

Simple google of the fault

Dreaded ESP Warning after 10 mins driving. Fault Code 18265

All roads lead to Rome...kinda thang?

[techfreak]

Simple google of the fault

Dreaded ESP Warning after 10 mins driving. Fault Code 18265

All roads lead to Rome...kinda thang?

Ah yes I did read this thread across my travels. Could well be the voltage regulator ...will need to test the output...

Would you know how to test this?

[techfreak]

Concerning this ....



I know on another thread I said sensor could be at fault... but it could be something else as well ... Link:- Air Con not working...advice please

Chadders had a regas 1st, then changed sensor, still has fault ... he has new compressor for sale ...

In chronological order :-

His regas thread Link:- Aircon issue problem or not??

His fault scan Link:- Aircon problem found on scan

His sensor change/compressor Link:- Air con ECON problem

You may need to look at MVB's or get some proper diags done for AC ...

I'm hoping it's not compressor :-( just reading those posts now...

Seeing as I already have the sensor I will try this then regas. If this does not fix it I will get the compressor checked out.

[MarkTM]

Tech

No idea as never have tested mine in any car...but once again google is my friend

How to Test Alternator Voltage Output (AutoUpkeep.com) - YouTube

[gupsterg]

As you have VCDS you may find that running the MVB's in the battery regulation module will show you the occurrence of fault ...

Link:- Audi Portal: ECU Diagnostic . Audi A6 4F (2005- ) . Energy Manager J644

I've found using this screen capture software easier to see a fault occurrence i) then wading through the logs created in VCDS ii) for posting/sharing ...

Link:- FastStone Screen Capture - The Best Screen Capture Software

Here is an example of me having used it Link:- BMK 3.0 TDi hunting erratic idle revs ( Have I got the most lemon A6!!! ) - Page 27

Also you can run an output test in module 61 which will excite alternator and show voltage output ...

Alternator test.jpg

[techfreak]

Many thanks guys...

I'll try all this out...

Google doesn't seem to want to by my friend at the moment ....I've been reading through a lot of various alternator failure threads and symptoms are similar but not the same.

So far I'm guessing that it is a fault somewhere in the alternator (most likely voltage regulator) and it's at the beginning stages of it's death as the car fires up fine, drives fine, all other electrics work fine.

The ESP fault is only during the first drive after the car has been sat for a good few hours.

Once driven for 10/15 mins then the fault does not occur again until the cycle is repeated.

I will test and report back

[MarkTM]

My recommendation would go through the cheapest fixes methodically first, namely:

1) Check battery with voltmeter and
2) If out then check connections/clean contacts
3) If 2 OK then purchase similar to this VW POLO T4 TOUREG BOSCH ALTERNATOR VOLTAGE REGULATOR 038903803E F00M145225 | eBay
4) Investigate alternator repair if no point 3 available
5) Move on to AC stuff...which will invariably be more expensive

[techfreak]

I've tested battery today with multimeter and it was12.38v.

I then opened car inserted key and immediately turned radio/climate control off and it was just touching 12v then fired her up (with everything off) and it dropped to around 10.5v then climbed to a steady 13.85v.

Turned lights,fans,radio on and it dropped to 13.73v then back up again to 13.85v.

I'll do a vcds log and I'll also take it to one of those garages that can do a proper load test to confirm but would this indicate a dying/dead battery?