Regular RPM Changes when Engine Cold and Electrical Consumers On (Golf MK6 1.6TDI)

airbus · Nov 27, 2018

Hi All,

Perhaps someone can assist. Since I have had it my car, a Golf MK6 2012 Model 1.6TDI (engine CAYC) has suffered from a slight but regular fluctuation in the RPM between 740-820rpm (as per VCDS) which you can feel through the steering wheel. Pre-Requisites for this to occur are engine cold and Electrical Consumers On (i.e rear demister, headlights, Heater on etc). It always disappears as soon as the engine is warmed up (10 mins or so). The fluctuation is regular and not random, like every couple of seconds or so only when the above requirements are met. I am noticing it a lot more since the weather has got colder in the UK and I use more consumers at startup, therefore it's getting more irritating requiring more investigation :confused:

The EGR Valve was changed early this year so this has been ruled out. Unfortunately I don't know whether the issue was apparent before then as that was under another owner.
The Injector deviation have been checked on all 4 cylinders and I can't see anything wrong there either (1mg max deviation on any one).
I have had injector issues previously (same engine, different car) and this has resulted in random and sporadic changes to the idle rpm, this is not.

Battery Voltage shows between 12.2-12.6V at rest and alternator shows charging well at between 14.5-14.8V when on. The battery is the original though so I am surprised it's still going strong after 6 years and 80K miles.

The car had the emissions fix performed on it last year but not sure if this would be related as I am not getting any actual driveability issues.

There are no relevant fault codes present in VCDS, I have attached a VCDS dump from earlier this year when the problem first occurred.

Has anyone experienced such an issue as I am running out of things to check? Thanks in advance.

Code:

Wednesday,09,May,2018,12:35:32:00352
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 7 x86
VCDS Version: 18.2.0.3
Data version: 20180212 DS287.0
www.Ross-Tech.com


VIN: WVWZZZ1KZBW31xxxx   License Plate: 
Mileage: 127900km-79473mi   Repair Order: 



--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Chassis Type: 1K-VW36 (7N0)
Scan: 01 03 08 09 10 15 16 17 19 25 2E 42 44 46 52 56 61 62 72 77
         

VIN: WVWZZZ1KZBW31xxxx   Mileage: 127900km-79473miles

01-Engine -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
04-Steering Angle -- Status: OK 0000
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- Status: Malfunction 0010
10-Park/Steer Assist -- Status: OK 0000
15-Airbags -- Status: OK 0000
16-Steering wheel -- Status: OK 0000
17-Instruments -- Status: OK 0000
19-CAN Gateway -- Status: OK 0000
25-Immobilizer -- Status: OK 0000
2E-Media Player 3 -- Status: OK 0000
42-Door Elect, Driver -- Status: OK 0000
44-Steering Assist -- Status: OK 0000
46-Central Conv. -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
56-Radio -- Status: Malfunction 0010
61-Battery Regul. -- Status: OK 0000
62-Door, Rear Left -- Status: OK 0000
72-Door, Rear Right -- Status: OK 0000
77-Telephone -- Status: OK 0000
 
-------------------------------------------------------------------------------
Address 01: Engine (J623-CAYC)       Labels:. 03L-906-023-CAY.clb
   Part No SW: 03L 997 557 T    HW: 03L 907 425 C
   Component: R4 1.6l TDI   H43 9982  
   Revision: --H43---    Serial number: 00000000000000
   Coding: 08114014032501080000
   Shop #: WSC 01357 011 00200
   ASAM Dataset: EV_ECM16TDI02103L997557T 003003
   ROD: EV_ECM16TDI.rod
   VCID: 4DB75AE91CD07E2CA3-8018

No fault code found.
Readiness: 0 0 0 0 0 

-------------------------------------------------------------------------------
Address 03: ABS Brakes (J104)       Labels:. 1K0-907-379-60EC1F.clb
   Part No SW: 1K0 907 379 BE    HW: 1K0 907 379 BE
   Component: ESP MK60EC1   H31 0108  
   Revision: 00H31001    
   Coding: 133B200D092300FFC81304E9901A0091310000
   Shop #: WSC 01357 011 00200
   VCID: 76C5D505C1C65DF432-8022

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC (J301)       Labels:| 3C8-907-336.clb
   Part No SW: 7N0 907 426 K    HW: 7N0 907 426 K
   Component: AC Manuell    H17 0202  
   Revision: 00001012    
   Coding: 0000000003
   Shop #: WSC 01357 011 00200
   ASAM Dataset: EV_Climatic A01005
   ROD: EV_ClimaBasis_VW36.rod
   VCID: 3C51072DB76AC7A404-8068

No fault code found.

-------------------------------------------------------------------------------
Address 09: Cent. Elect. (J519)       Labels:. 1K0-937-08x-09.clb
   Part No SW: 1K0 937 084 D    HW: 1K0 937 084 D
   Component: BCM PQ35  B   103 0615  
   Revision: 00103 AE    
   Coding: 48180A3A8825F1C040080080340000E443510088436D8160648087200041
   Shop #: WSC 01357 011 00200
   VCID: 2F4B20617E1C2C3CB1-807A

   Subsystem 1 - Part No: 5K2 955 119 
   Component: Wischer 06041  26  0512 
   Coding: 009795

   Subsystem 2 - Part No: 1K0 955 559 AH  Labels: 1K0-955-559-AG.CLB
   Component: RLS 200411 05  54  0403 
   Coding: 0330AD

   Subsystem 3 - Part No: 1K8 951 171 
   Component: DWA-Sensor 00  001 0104 

   Subsystem 4 - Part No: 1K8 951 605 B
   Component: LIN BACKUP HO  H11 9005 

2 Faults Found:
00332 - Control Circuit for Tank Flap 
            007 - Short to Ground
             Freeze Frame:
                    Fault Status: 01100111
                    Fault Priority: 4
                    Fault Frequency: 1
                    Reset counter: 214
                    Mileage: 127875 km
                    Time Indication: 0
                    Date: 2012.09.24
                    Time: 14:13:36

             Freeze Frame:
                        Term 15 Off
                    Voltage: 11.85 V
                        OFF
                        ON
                        Term 50 Off
                        OFF
                        OFF

02395 - Parking Light Front Right (M3) 
            010 - Open or Short to Plus - Intermittent
             Freeze Frame:
                    Fault Status: 00101010
                    Fault Priority: 2
                    Fault Frequency: 6
                    Reset counter: 254
                    Mileage: 127875 km
                    Time Indication: 0
                    Date: 2012.09.24
                    Time: 14:17:19

             Freeze Frame:
                        Term 15 On
                    Voltage: 14.65 V
                        ON
                        ON
                        Term 50 On
                        OFF
                        OFF


-------------------------------------------------------------------------------
Address 10: Park/Steer Assist (J446)       Labels:. 3C8-919-475.clb
   Part No SW: 5K0 919 475 E    HW: 5K0 919 475 E
   Component: PARKHILFE 8K  H01 0012  
   Revision: --------    Serial number: 12501110100802
   Coding: 108001
   Shop #: WSC 01357 011 00200
   VCID: 38591B3D8B52EB84E0-806C

No fault code found.

-------------------------------------------------------------------------------
Address 15: Airbags (J234)       Labels:| 5K0-959-655.clb
   Part No SW: 5C0 959 655 B    HW: 5C0 959 655 B
   Component: AirbagVW10    013 0613  
   Serial number: 003G5RA42UNY  
   Coding: 00003948
   Shop #: WSC 01357 011 00200
   ASAM Dataset: EV_AirbaVW10SMEVW360 A01014
   ROD: EV_AirbaVW10SMEVW360.rod
   VCID: 314F261960283ACCA7-8064

   Crash sensor for side airbag: driver side: 
   Subsystem 1 - Part No SW: 5K0 959 354     HW: 5K0 959 354 
   Component: S.Sens.Fahr.V  H01 ---- 
   Serial number: 3572MSME712E165FZZZ1

   Crash sensor for side airbag: front passenger side: 
   Subsystem 2 - Part No SW: 5K0 959 354     HW: 5K0 959 354 
   Component: S.Sens.Beif.V  H01 ---- 
   Serial number: 3582MSME7F34635EZZZ8

   Crash sensor for side airbag: rear: driver side: 
   Component: S.Sens.Fahr.H  --- ---- 
   Serial number: 3512QSME7A451D4EZZZ6

   Crash sensor for side airbag: rear: passenger side: 
   Component: S.Sens.Beif.H  --- ---- 
   Serial number: 3522QSME4A441D16ZZZZ

No fault code found.

-------------------------------------------------------------------------------
Address 16: Steering wheel (J527)       Labels:| 5K0-953-569.clb
   Part No SW: 5K0 953 507 BC    HW: 5K0 953 549 E
   Component: Lenks.Modul   008 0080  
   Revision: --------    Serial number:  90440KDJ001AV
   Coding: 1082140000
   Shop #: WSC 01357 011 00200
   ASAM Dataset: EV_SMLSNGKUDS A05001
   ROD: EV_SMLSNGKUDS_A05.rod
   VCID: 72CDE915A5AE41D41E-8026

   Multifunction steering wheel control module: 
   Subsystem 1 - Part No SW: 3C8 959 537 D    HW: 3C8 959 537 D  Labels: 3C8-959-537.CLB
   Component: E221__MFL-TK6  H06 0022 
   Serial number: 40000000000000324004
   Coding: E20000

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments (J285)       Labels:| 5K0-920-xxx-17.clb-SRI1
   Part No SW: 5K0 920 971 A    HW: 5K0 920 971 A
   Component: KOMBI         H20 0420  
   Serial number: 00000000000000
   Coding: 470B00
   Shop #: WSC 01357 011 00200
   ASAM Dataset: EV_Kombi_UDS_VDD_RM09 A04089
   ROD: EV_Kombi_UDS_VDD_RM09_004_VW36.rod
   VCID: 2D773A697C105E2C83-8078

No fault code found.

-------------------------------------------------------------------------------
Address 19: CAN Gateway (J533)       Labels:. 7N0-907-530-V2.clb
   Part No SW: 7N0 907 530 D    HW: 1K0 907 951 
   Component: J533  Gateway H35 0614  
   Revision:   H35       Serial number: 140411F2001094
   Coding: 350003
   Shop #: WSC 01357 011 00200
   VCID: 314F261968283ACCA7-8064

No fault code found.

-------------------------------------------------------------------------------
Address 25: Immobilizer (J334)       Labels:| 5K0-920-xxx-25.clb
   Part No SW: 5K0 953 234     HW: 5K0 953 234 
   Component: IMMO          H20 0420  
   Serial number: 00000000000000
   Coding: 000000
   Shop #: WSC 00000 000 00000
   ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03008
   ROD: EV_Immo_UDS_VDD_RM09.rod
   VCID: 6AFDF1758D7E8914A6-803E

No fault code found.

-------------------------------------------------------------------------------
Address 2E: Media Player 3 (J650)       Labels:. 5N0-035-342.lbl
   Part No SW: 5N0 035 342 D    HW: 5N0 035 342 D
   Component: SG EXT.PLAYER H13 0150  
   Revision: A1001003    Serial number: 7669823626    
   Coding: 010000
   Shop #: WSC 01357 011 00200
   VCID: 2879CB7D5BF27B0470-807C

No fault code found.

-------------------------------------------------------------------------------
Address 42: Door Elect, Driver        Labels:. 1K0-959-701-MIN3.clb
   Part No SW: 5K0 959 701 B    HW: 5K0 959 701 B
   Component: Tuer-SG         009 2120  
   Coding: 0131764
   Shop #: WSC 01357 011 00200
   VCID: 314F2619A8283ACCA7-8064

No fault code found.

-------------------------------------------------------------------------------
Address 44: Steering Assist        Labels: 1K0-909-14x-GEN3.clb
   Part No: 1K0 909 144 M
   Component: EPS_ZFLS Kl. 69     3201  
   Revision: 00H20000    
   Shop #: WSC 01357 011 00200
   VCID: 34412F0D573A0FE4CC-8060

No fault code found.

-------------------------------------------------------------------------------
Address 52: Door Elect, Pass.        Labels:. 1K0-959-702-MAX3.clb
   Part No SW: 5K0 959 702 C    HW: 5K0 959 702 C
   Component: Tuer-SG         009 2120  
   Coding: 0132020
   Shop #: WSC 01357 011 00200
   VCID: 33432C11523408DCD5-8066

No fault code found.

-------------------------------------------------------------------------------
Address 56: Radio (J0503)       Labels:. 5M0-035-1xx-56.clb
   Part No SW: 3C8 035 195 A    HW: 3C8 035 195 A
   Component: Radio RCD510  041 0166  
   Revision: 00000001    Serial number: VWZ1Z3L0746133
   Coding: 0100040004
   Shop #: WSC 01357 011 00200
   VCID: 2665C54551E66D7442-8072

1 Fault Found:
00821 - Antenna 2 for Radio (R93) 
            007 - Short to Ground
             Freeze Frame:
                    Fault Status: 01100111
                    Fault Priority: 5
                    Fault Frequency: 1
                    Reset counter: 214
                    Mileage: 127875 km
                    Time Indication: 0
                    Date: 2012.09.24
                    Time: 14:10:37


-------------------------------------------------------------------------------
Address 61: Battery Regul. (J840)       Labels:. 1K0-907-534.clb
   Part No SW: 7N0 907 534     HW: 1K0 907 951 
   Component: Batt.regelung H35 0614  
   Serial number: 140411F2001094
   Coding: 030B185A
   Shop #: WSC 01357 011 00200
   VCID: 71CFE619A8A87ACCE7-8024

   Subsystem 1 - Part No SW: 1K0 915 181 F    HW: 1K0 915 181 A
   Component: J367-BDM  H07 0150 
   Serial number: 00000000009370226942

No fault code found.

-------------------------------------------------------------------------------
Address 62: Door, Rear Left        Labels:. 1K0-959-703-GEN3.clb
   Part No SW: 5K0 959 703 D    HW: 5K0 959 703 D
   Component: Tuer-SG         007 2101  
   Coding: 0131216
   Shop #: WSC 01357 011 1012552
   VCID: 354712095C4016ECFB-8060

No fault code found.

-------------------------------------------------------------------------------
Address 72: Door, Rear Right        Labels:. 1K0-959-704-GEN3.clb
   Part No SW: 5K0 959 704 D    HW: 5K0 959 704 D
   Component: Tuer-SG         007 2101  
   Coding: 0131216
   Shop #: WSC 01357 011 1012552
   VCID: 3645150541461DF4F2-8062

No fault code found.

-------------------------------------------------------------------------------
Address 77: Telephone (J412)       Labels:| 7P6-035-730.clb
   Part No SW: 5K0 035 730 B    HW: 5K0 035 730 B
   Component: TELEFON       H09 1020  
   Revision: 1B001001    Serial number: 00007669764269
   Coding: 0A01000000010101
   Shop #: WSC 01357 011 00200
   ASAM Dataset: UHVNA A01009
   ROD: UHVNA.rod
   VCID: 2461DF4D2FDA9F645C-8070

No fault code found.

End-------------------------(Elapsed Time: 03:02)--------------------------

Larry Manton · Nov 28, 2018

Airbus, not sure on this model but on Cummins truck fluctuation during first minutes normal as glow grid pulls almost 120 amps. Not saying this is how this system works but maybe??, would look at amp draws on the VAG during this period for a clue as issue seems when cold then not when warm.

Another clue, is there a subtle dimming of all lights of and on during this?

LARIMORE

airbus · Nov 28, 2018

Larry Manton said:
Airbus, not sure on this model but on Cummins truck fluctuation during first minutes normal as glow grid pulls almost 120 amps. Not saying this is how this system works but maybe??, would look at amp draws on the VAG during this period for a clue as issue seems when cold then not when warm.

LARIMORE

LARIMORE

Hi Larry, thanks for the reply.

It could well be a current draw that is causing this, but the voltage regulation module shows the battery voltage at about 14.5-14.8v when the car is started. I did notice though that with basic ignition on (and daylight running lights on by default), the voltage first thing in the morning is 12v according to VCDS. Also after going into module 61 (battery regulation), I see a value for 85% battery charge. Could this be an issue I wonder, who knows... I do know its the original battery so I suppose I could change it if there is a chance of it helping. Just a little reluctant because it starts fine and the stop/start works fine, so it doesn't feel like end of life :rolleyes:

PetrolDave · Nov 28, 2018

airbus said:
Also after going into module 61 (battery regulation), I see a value for 85% battery charge.

That's not unusual, newer VAG cars with start/stop and battery management try to keep the battery charge somewhere near 70% to 80% - to allow headroom for using the alternator to provide extra load when using engine braking by putting more charge into the battery (sometimes referred to as the vehicle being a micro-Hybrid).

airbus · Nov 28, 2018

PetrolDave said:
That's not unusual, newer VAG cars with start/stop and battery management try to keep the battery charge somewhere near 70% to 80% - to allow headroom for using the alternator to provide extra load when using engine braking by putting more charge into the battery (sometimes referred to as the vehicle being a micro-Hybrid).

Hi PetrolDave, OK good to know thanks.

Is it possible the battery is a contributory factor in this or no chance since the alternator is pulling the electric current in from the engine after start? I guess the battery would be certainly the issue if it didn't start in the first place. The issue never occurs on a warmed up engine...

PetrolDave · Nov 28, 2018

airbus said:
The battery is the original though so I am surprised it's still going strong after 6 years and 80K miles.

airbus said:
the voltage first thing in the morning is 12v according to VCDS.

airbus said:
Is it possible the battery is a contributory factor in this

I suggest you check the battery voltage first thing in the morning with a meter. 12V does seem lower than I would expect (except on really cold mornings), so I'm suspicious of the battery - especially as you say it's 6 years old, so I doubt whether it is actually "still going strong". The recent arrival of Winter in the UK might just have been too much for such an old battery to cope with.

airbus · Nov 28, 2018

The battery voltage at 12v is actually shown through VCDS with basic ignition circuit on (to get VCDS working) and daytime running lights on (by default). I just tried it on a multimeter at the battery direct with everything off, it's showing 12.5v. The issue has been going on since early this year unfortunately, but it's been less noticeable as I have had less electrical consumers on, nowl this cold spell has started I am noticing it more often

PetrolDave · Nov 29, 2018

airbus said:
The issue has been going on since early this year unfortunately, but it's been less noticeable as I have had less electrical consumers on, nowl this cold spell has started I am noticing it more often

That plus the battery being 6 years old strongly suggests a battery that is starting to fail due to old age.

downtime · Nov 29, 2018

^ I agree with PetrolDave here. I had the same symptoms like OP in our previous Golf Plus MK5 1.6FSI. On cold weather (which we have around 6 months per year here in Finland) the engine rpm fluctuated pretty much from ~700 - 1000rpm until the engine had warmed up.
It got to a point that the car barely started on freezing temperatures. After battery change the fluctuation was not completely gone but was much more civilized. I would say the range was not more than 100rpm between normal and the higher mode.

Some fluctuation is normal as electric consumers suck juice from the battery and the electronics compensate that by increasing the rpm to have more current produced from alternator.

airbus · Nov 29, 2018

Thanks both of you for the responses. I will certainly consider changing the AGM Battery installed. I thought that the battery was kind of redundant once the car is started since the power is being fed in by the alternator.

I'd also be interested to know whether anyone has had issues with the idle on their car since having the emissions fix completed. The previous owner did it to my car so it's on software version 9982 now. The only bad stories I have read are the car going into limp mode, the egr failing...other stuff like that as a consequence of actually driving the vehicle, not just idling. I dont suffer any issues whilst driving along, the previous owner may have as the got the egr changed after the software update, good for me perhaps...

I was going to get a software rollback done at an independent to see whether that may improve it, but if the chances are slim, then not worth it (could probably introduce more issues anyway)...who knows.

Good to know that one person has experienced a similiar symptom and found it be a battery issue more or less. It would be interesting to see if anybody with a1.6TDI has also experienced the same symptoms.

Thanks for the replies.

Regular RPM Changes when Engine Cold and Electrical Consumers On (Golf MK6 1.6TDI)

airbus

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Larry Manton

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airbus

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PetrolDave

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airbus

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PetrolDave

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airbus

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PetrolDave

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downtime

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airbus

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