Experiencing electrical problems with your Audi Q7 can be frustrating. A common culprit, and often the first point of investigation, is the car battery. Many Audi Q7 owners encounter issues ranging from central locking malfunctions to more perplexing electrical behavior, and a failing battery is frequently at the heart of these problems. Let’s delve into a real-world scenario to understand how a battery issue can manifest in your Audi Q7 and what steps you can take.
One Audi Q7 owner recently reported a sudden cessation of their central locking system. Initial diagnostics using a VCDS scan revealed a concerningly low battery voltage of just 11.65V with the engine off. While the alternator appeared to be charging correctly at 14.3V and 46A when the engine was running, the battery itself seemed incapable of holding a sufficient charge. This immediately raised suspicions of a failing battery being the primary cause of the central locking malfunction. The logic was sound: a weak battery could lead to systems shutting down, including the central locking. Therefore, an Audi Q7 Battery Change seemed like a necessary first step.
However, this Q7 also exhibited other unusual symptoms that didn’t neatly align with a simple low-voltage scenario. Upon turning off the ignition and removing the key, the MMI system remained active, the tail lights stayed illuminated (in auto-lights mode), the power windows continued to function, and the steering lock failed to engage. It was as if the vehicle hadn’t registered the key’s removal, leading to concerns that the battery drain might be a symptom of a deeper underlying issue, such as a faulty ignition switch keeping systems unnecessarily powered and consequently draining the battery.
To further investigate, a comprehensive VCDS scan was performed, revealing a multitude of fault codes across various modules. Notably, the scan highlighted “Supply Voltage Terminal 30” and “Function Limitation due to Under-Voltage” errors within modules like ABS Brakes and Acc/Start Auth. These codes strongly suggest that voltage supply issues are indeed present and impacting different systems within the vehicle. The scan also revealed faults related to headlight range and radio, which can sometimes be linked to voltage fluctuations.
Saturday,20,April,2019,19:56:19:35988 VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x64
VCDS Version: 18.9.1.0 (x64) Data version: 20190114 DS296.0 www.Ross-Tech.com
VIN: WAUZZZ4L78D018907 License Plate: HYQ360 Mileage: 173950km-108087mi Repair Order:
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Chassis Type: 4L (4L0)
Scan: 01 02 03 05 07 08 09 0E 15 16 17 18 19 1E 37 42 46 47 4F 52 55 56 61 62 67 6C 6D 6F 72 76 77
VIN: WAUZZZ4L78D018907 Mileage: 173950km-108087miles
00-Steering Angle Sensor -- Status: OK 0000
01-Engine -- Status: OK 0000
02-Auto Trans -- Status: OK 0000
03-ABS Brakes -- Status: Malfunction 0010
05-Acc/Start Auth. -- Status: Malfunction 0010
07-Control Head -- Status: OK 0000
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- Status: Malfunction 0010
0E-Media Player 1 -- Status: OK 0000
15-Airbags -- Status: OK 0000
16-Steering wheel -- Status: OK 0000
17-Instruments -- Status: OK 0000
18-Aux. Heat -- Status: Malfunction 0010
19-CAN Gateway -- Status: OK 0000
1E-Media Player 2 -- Status: OK 0000
37-Navigation -- Status: OK 0000
42-Door Elect, Driver -- Status: OK 0000
46-Central Conv. -- Status: OK 0000
47-Sound System -- Status: Malfunction 0010
4F-Centr. Electr. II -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
55-Headlight Range -- Status: Malfunction 0010
56-Radio -- Status: Malfunction 0010
61-Battery Regul. -- Status: Malfunction 0010
62-Door, Rear Left -- Status: Malfunction 0010
67-Voice Control -- Status: OK 0000
6C-Back-up Cam. -- Status: OK 0000
6D-Trunk Elect. -- Status: OK 0000
6F-Centr. Conv. II -- Status: OK 0000
72-Door, Rear Right -- Status: Malfunction 0010
76-Park Assist -- Status: OK 0000
77-Telephone -- Status: OK 0000
-------------------------------------------------------------------------------
Address 01: Engine Labels: 059-907-401-ASB.clb
Part No SW: 4L0 910 401 R HW: 4L0 907 401
Component: 3.0L V6TDI G000AG 0020 Revision: --H04--- Serial number:
Coding: 0011779 Shop #: WSC 31414 790 00001 VCID: 3169068CA8A5CEC262-8064
No fault code found.
-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: 09D-927-750.clb
Part No SW: 09D 927 750 FS HW: 09D 927 750 FS
Component: AL 750 6A 1000 Revision: 00H64000 Serial number:
Coding: 0000504 Shop #: WSC 31414 790 00001 VCID: 04079F5847978B6AF9-8050
No fault code found.
-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels:. 4L0-910-517-V2.clb
Part No SW: 4L0 910 517 B HW: 4L0 614 517 D
Component: ESP ALLRAD MK25E1 0010 Revision: 00H30001 Coding: 0099473
Shop #: WSC 31414 790 00001 VCID: 2959EEEC8075B602AA-807C
1 Fault Found:
00668 - Supply Voltage Terminal 30
002 - Lower Limit Exceeded - Intermittent
Freeze Frame:
Fault Status: 00100010
Fault Priority: 2
Fault Frequency: 1
Reset counter: 204
Mileage: 173701 km
Time Indication: 0
Date: 2019.04.14
Time: 09:55:57
Freeze Frame:
Count: 64
Count: 8261
Count: 128
Count: 39680
-------------------------------------------------------------------------------
Address 05: Acc/Start Auth. Labels:. 4F0-910-852.clb
Part No SW: 4F0 910 852 HW: 4F0 905 852 B
Component: FBSAUDIC6 ELV H31 0230 Revision: 09010701 Serial number: 10601500866926
Coding: 0000147 Shop #: WSC 31414 790 00001 VCID: 63C5BCC4A2D92C52A0-8036
Subsystem 1 - Part No: 4F0 910 131 A
Component: FBSAUDIC6 EZS H45 0080
Subsystem 2 - Part No: 4F0 910 220
Component: FBSAUDIC6 IDG H01 0040
3 Faults Found:
00956 - Key 2
002 - Lower Limit Exceeded - Intermittent
Freeze Frame:
Fault Status: 00110010
Fault Priority: 3
Fault Frequency: 2
Reset counter: 40
Mileage: 173011 km
Time Indication: 0
Date: 2019.03.15
Time: 08:03:16
01176 - Key
004 - No Signal/Communication - Intermittent
Freeze Frame:
Fault Status: 00100100
Fault Priority: 2
Fault Frequency: 8
Reset counter: 223
Mileage: 173943 km
Time Indication: 0
Date: 2019.04.20
Time: 14:02:03
00446 - Function Limitation due to Under-Voltage
002 - Lower Limit Exceeded - Intermittent
Freeze Frame:
Fault Status: 00100010
Fault Priority: 2
Fault Frequency: 1
Reset counter: 200
Mileage: 173679 km
Time Indication: 0
Date: 2019.04.13
Time: 08:14:56
-------------------------------------------------------------------------------
Address 07: Control Head Labels: 4L0-910-7xx-07-H.clb
Part No SW: 4L0 910 731 L HW: 4E0 035 729 A
Component: Interfacebox H43 4220 Revision: 00000000 Serial number: 387H2077556485
Coding: 0002002 Shop #: WSC 31414 790 00001 VCID: 3169068CA8A5CEC262-8064
Subsystem 1 - Part No: 4L0 910 609
Component: E0380 BedienteilH01 0060
Subsystem 2 - Serial number: 00000000838279
Subsystem 3 - Serial number: 0116.08.070000000100010294ÿ
Subsystem 4 - Serial number: 010294ÿ
No fault code found.
-------------------------------------------------------------------------------
Address 08: Auto HVAC Labels: None
Part No SW: 4L0 910 043 HW: 4L0 820 043 E
Component: KLIMABETAETIGUNGH05 0060 Revision: 00---012 Serial number: 00000000127582
Coding: 0001110 Shop #: WSC 31414 790 00001 VCID: 61C9B6CCB8C53E42B2-8034
No fault code found.
-------------------------------------------------------------------------------
Address 09: Cent. Elect. Labels: 4F0-910-279.lbl
Part No SW: 4F0 910 279 K HW: 4F0 907 279
Component: ILM Fahrer H18 0250 Revision: 00000000 Serial number: 4F0907279
Coding: 0003121 Shop #: WSC 31414 790 00001 VCID: 3169068CA8A5CEC262-8064
Subsystem 1 - Part No: 4L2 910 113 Labels: 1KX-955-119.CLB
Component: Wischer AU716 H10 0100 Coding: 00064792 Shop #: WSC 31414
Subsystem 2 - Part No: 4E0 910 557 A Labels: 8K0-955-559.CLB
Component: REGENLICHTSENSORH13 0090 Coding: 00150059 Shop #: WSC 31414
5 Faults Found:
02745 - Bulb for Daytime Running Light; Left
011 - Open Circuit
Freeze Frame:
Fault Status: 01101011
Fault Priority: 2
Fault Frequency: 1
Reset counter: 183
Mileage: 167276 km
Time Indication: 0
Date: 2018.09.16
Time: 11:37:00
02746 - Bulb for Daytime Running Light; Right
011 - Open Circuit
Freeze Frame:
Fault Status: 01101011
Fault Priority: 2
Fault Frequency: 1
Reset counter: 183
Mileage: 167276 km
Time Indication: 0
Date: 2018.09.16
Time: 11:37:00
01494 - Bulb for Parking Lamps; Left (M1)
011 - Open Circuit
Freeze Frame:
Fault Status: 01101011
Fault Priority: 2
Fault Frequency: 2
Reset counter: 183
Mileage: 173948 km
Time Indication: 0
Date: 2019.04.20
Time: 18:47:00
01498 - Bulb for Parking Lamps; Right (M3)
011 - Open Circuit
Freeze Frame:
Fault Status: 01101011
Fault Priority: 2
Fault Frequency: 1
Reset counter: 183
Mileage: 173948 km
Time Indication: 0
Date: 2019.04.20
Time: 19:06:00
01498 - Bulb for Parking Lamps; Right (M3)
007 - Short to Ground - Intermittent
Freeze Frame:
Fault Status: 00100111
Fault Priority: 2
Fault Frequency: 39
Reset counter: 223
Mileage: 173588 km
Time Indication: 0
Date: 2019.04.07
Time: 15:27:00
-------------------------------------------------------------------------------
Address 0E: Media Player 1 Labels: 4E0-910-111.lbl
Part No SW: 4L0 910 110 A HW: 4L0 035 110
Component: MP3-Changer H45 0350 Revision: 00045006 Serial number: AUZ5ZBG1226503
Shop #: WSC 00000 000 00000 VCID: 1D31CA3CC43D5AA2D6-8048
No fault code found.
-------------------------------------------------------------------------------
Address 15: Airbags Labels: 4L0-910-655.lbl
Part No SW: 4L0 910 655 D HW: 4L0 959 655 C
Component: 70 AIRBAG AUDI8RH42 0230 Revision: 03H42000 Serial number: 00399D03DRUL
Coding: 0014128 Shop #: WSC 31414 790 00001 VCID: 2E531DF0B99BD13A7F-807A
Subsystem 1 - Serial number: 6332QSME360C400FF
Subsystem 2 - Serial number: 6342QSME360D072DK
Subsystem 3 - Serial number: 6352QSME3850294DL
Subsystem 4 - Serial number: 6362QSME36070F1FP
Subsystem 5 - Serial number: 63734SME386D7A3BJ
Subsystem 6 - Serial number: 63834SME36521637Z
No fault code found.
-------------------------------------------------------------------------------
Address 16: Steering wheel Labels: 4F0-910-549.lbl
Part No SW: 4F0 910 549 A HW: 4F0 953 549 D
Component: J0527 0410 Revision: 00H02000 Serial number: 90026072020007
Coding: 0102142 Shop #: WSC 31414 790 00001 VCID: 275DE8D496618072BC-8072
Subsystem 1 - Part No: XXXXXXXXXXX
Component: E0221 H02 0030
No fault code found.
-------------------------------------------------------------------------------
Address 17: Instruments Labels: 4L0-910-xxx-17.lbl
Part No SW: 4F0 910 930 C HW: 4L0 920 930 T
Component: KOMBIINSTR. M73 H21 0240 Revision: 00700000 Serial number: 73Y52XV87
Coding: 3649758 Shop #: WSC 00070 067 57207 VCID: 2345FCC4E2596C52E0-8076
No fault code found.
-------------------------------------------------------------------------------
Address 18: Aux. Heat Labels: None
Part No SW: 4L0 910 105 HW: 4L0 815 071 D
Component: Heizgeraet H08 0080 Revision: 0000000C Serial number: 00000009014264
Coding: 0000001 Shop #: WSC 31414 790 00001 VCID: 60CFB3C8B3CF374ABD-8034
2 Faults Found:
01412 - Glow-Plug with Flame Monitoring (Q8)
008 - Implausible Signal
02251 - Heater Unit Locked
000 - -
-------------------------------------------------------------------------------
Address 19: CAN Gateway Labels:. 4L0-910-468.clb
Part No SW: 4L0 910 468 A HW: 4L0 907 468 B
Component: J533__Gateway H06 0060 Revision: 00H06000 Serial number: 1100B077268415
Coding: F55BFE7770720200 Shop #: WSC 31414 790 00001 VCID: 2D511AFCB49DAA2246-8078
No fault code found.
-------------------------------------------------------------------------------
Address 1E: Media Player 2 (R192) Labels:. 4E0-035-785.lbl
Part No SW: 4E0 035 785 B HW: 4E0 035 785 B
Component: SG ext.Player H15 0700 Revision: 00000000 VCID: 275DE8D456618072BC-8072
No fault code found.
-------------------------------------------------------------------------------
Address 37: Navigation Labels: 4E0-910-88x-37.lbl
Part No SW: 4E0 910 888 E HW: 4E0 919 887 M
Component: MNS ECE H50 1050 Revision: 00000000 Serial number: 399H 077585023
Shop #: WSC 00070 824 83289 VCID: 306F0388A3AFC7CA6D-8064
No fault code found.
-------------------------------------------------------------------------------
Address 42: Door Elect, Driver Labels: 4L0-910-793-42.lbl
Part No SW: 4L0 910 793 C HW: 4L0 959 793 C
Component: TSG FA H21 0150 Coding: 0000539 Shop #: WSC 31414 790 00001 VCID: 306F0388A3AFC7CA6D-8064
No fault code found.
-------------------------------------------------------------------------------
Address 46: Central Conv. Labels:. 4L0-910-289.lbl
Part No SW: 4L0 910 289 F HW: 4L0 907 289 C
Component: Komfortgeraet H07 0040 Revision: 0040 --- Serial number: 01060471200000
Coding: 7602317 Shop #: WSC 06111 109 68793 VCID: 33650C8452B9FCD210-8066
No fault code found.
-------------------------------------------------------------------------------
Address 47: Sound System (J525) Labels: Redir Fail!
Part No SW: 4L0 910 223 H HW: 4L0 035 223 C
Component: DSP-AU716-RD H07 0250 Revision: S0600000 Coding: 030100
Shop #: WSC 31414 790 00001 VCID: 2959EEEC4075B602AA-807C
2 Faults Found:
02558 - Rear Left Mid-Range/Woofer Loudspeaker (R159)
011 - Open Circuit - Intermittent
Freeze Frame:
Fault Status: 00101011
Fault Priority: 5
Fault Frequency: 12
Reset counter: 223
Mileage: 168317 km
Time Indication: 0
Date: 2018.11.05
Time: 09:18:55
Freeze Frame:
Voltage: 11.70 V
Temperature: 18.0°C
Bin. Bits: 00000011
00871 - Bass Speaker Front Right (R23)
011 - Open Circuit - Intermittent
Freeze Frame:
Fault Status: 00101011
Fault Priority: 5
Fault Frequency: 1
Reset counter: 223
Mileage: 172095 km
Time Indication: 0
Date: 2019.02.10
Time: 10:03:02
Freeze Frame:
Voltage: 11.90 V
Temperature: 32.0°C
Bin. Bits: 00000011
-------------------------------------------------------------------------------
Address 4F: Centr. Electr. II Labels: 4F0-910-280.lbl
Part No SW: 4F0 910 280 HW: 4F0 907 280
Component: ILM Beifahrer H12 0100 Revision: Serial number: 00000000243224
Coding: 0011001 Shop #: WSC 31414 790 00001 VCID: 5EB38D3089BB01BA8F-800A
No fault code found.
-------------------------------------------------------------------------------
Address 52: Door Elect, Pass. Labels: 4L0-910-793-52.lbl
Part No SW: 4L0 910 792 C HW: 4L0 959 792 C
Component: TSG BF H21 0150 Coding: 0000539 Shop #: WSC 31414 790 00001 VCID: 2F6D00F4BE91D83274-807A
No fault code found.
-------------------------------------------------------------------------------
Address 55: Headlight Range Labels: 4F0-910-357.lbl
Part No SW: 4F0 910 357 F HW: 4F0 907 357 F
Component: AFS 1 H01 0020 Revision: 00000001 Serial number:
Coding: 0000021 Shop #: WSC 31414 790 00001 VCID: 2959EEEC8075B602AA-807C
Subsystem 1 - Part No: NOSUBSYSTEM Component: AFS-Modul links
Subsystem 2 - Part No: NOSUBSYSTEM Component: AFS-Modul rechts
1 Fault Found:
02071 - Local Databus
004 - No Signal/Communication - MIL ON
Freeze Frame:
Fault Status: 11100100
Fault Priority: 2
Fault Frequency: 254
Reset counter: 183
Mileage: 167272 km
Time Indication: 0
Date: 2018.09.16
Time: 11:37:02
-------------------------------------------------------------------------------
Address 56: Radio Labels: 4E0-910-541.lbl
Part No SW: 4E0 910 541 Q HW: 4E0 035 541 S
Component: TUNER EU/US/RDW H42 0620 Revision: 00000000 Serial number: 388H$077640682
Coding: 0000001 Shop #: WSC 31414 790 00001 VCID: 2E531DF0B99BD13A7F-807A
2 Faults Found:
00532 - Supply Voltage B+
002 - Lower Limit Exceeded - Intermittent
Freeze Frame:
Fault Status: 00100010
Fault Priority: 7
Fault Frequency: 3
Reset counter: 223
Mileage: 165837 km
Time Indication: 0
Date: 2018.08.21
Time: 17:52:37
00446 - Function Limitation due to Under-Voltage
002 - Lower Limit Exceeded - Intermittent
Freeze Frame:
Fault Status: 00100010
Fault Priority: 7
Fault Frequency: 229
Reset counter: 223
Mileage: 165837 km
Time Indication: 0
Date: 2018.08.21
Time: 17:20:29
-------------------------------------------------------------------------------
Address 61: Battery Regul. Labels: 4F0-910-181.lbl
Part No SW: 4L0 910 181 A HW: 4L0 915 181
Component: J0644 BEM H12 0690 Revision: -------- Serial number: 00000000019134
Shop #: WSC 06111 109 68793 VCID: 2541E2DCEC6D92628E-8070
Subsystem 1 - Part No: 4F0 915 105 D
Component: von VA0 0708091116 Coding: 344630393135313035442056413030373038303931313136 Shop #: WSC 31414 790 00001
1 Fault Found:
03041 - Energy Management Active
000 - - - Intermittent
Freeze Frame:
Fault Status: 00100000
Fault Priority: 7
Fault Frequency: 2
Reset counter: 255
Mileage: 167353 km
Time Indication: 0
Date: 2018.09.20
Time: 17:23:36
-------------------------------------------------------------------------------
Address 62: Door, Rear Left Labels: 4L0-910-795.lbl
Part No SW: 4L0 910 795 C HW: 4L0 959 795 C
Component: TSG HL H21 0150 Coding: 0000002 Shop #: WSC 31414 790 00001 VCID: 326B0980ADA3F5DA1B-8066
1 Fault Found:
02111 - Motor for Window Regulator
005 - No or Incorrect Basic Setting / Adaptation
Freeze Frame:
Fault Status: 01100101
Fault Priority: 3
Fault Frequency: 1
Reset counter: 123
Mileage: 173369 km
Time Indication: 0
Date: 2019.03.30
Time: 15:17:47
-------------------------------------------------------------------------------
Address 67: Voice Control Labels: 4E0-910-75x-67.lbl
Part No SW: 4E0 910 754 S HW: 4E0 035 753 A
Component: SDS 3502 UK H46 0630 Revision: 00000000 Serial number: 00000707130329
Shop #: WSC 12336 024 394758 VCID: 3663359041CBE9FA37-8062
No fault code found.
-------------------------------------------------------------------------------
Address 6C: Back-up Cam. Labels: 4L0-910-441.clb
Part No SW: 4L0 910 441 A HW: 4L0 907 441 A
Component: J772__Rearview 0050 Revision: --H12--- Serial number: 525PA8-J7740ZN
Coding: 1021101 Shop #: WSC 31414 790 00001 VCID: 2447FFD8E7576B6A99-8070
No fault code found.
-------------------------------------------------------------------------------
Address 6D: Trunk Elect. Labels: None
Part No SW: 4L0 910 945 HW: 4L0 827 851 C
Component: ValeoHeckdeckel H24 0290 Revision: --H24001 Serial number: E5030000B
Shop #: WSC 98765 666 38354 VCID: 6CD7D7F84F07632A11-8038
Subsystem 1 - Part No: 4L0 910 946
Component: ValeoHeckdeckel H24 0290
Subsystem 2 - Serial number: E5030100B
Subsystem 3 - Serial number: RD18.08.07--H24001001B0135ÿ
Subsystem 4 - Serial number: 1B0135ÿ
No fault code found.
-------------------------------------------------------------------------------
Address 6F: Centr. Conv. II Labels:. 4L0-910-290.lbl
Part No SW: 4L0 910 290 A HW: 4L0 907 290 A
Component: ILM HINTEN 2 H05 0060 Revision: AAH05061 Serial number: 003019119-----
Coding: 0003591 Shop #: WSC 31414 790 00001 VCID: 2643E5D0916B997A87-8072
Subsystem 1 - Part No: 4L0 910 591
Component: J_245_EE16_SKB09H10 0200
Subsystem 2 - Part No: 4L0 910 591
Component: J_394_EE16_SKB09H10 0200
Subsystem 3 - Part No: 4L0 910 591
Component: J_392_EE16_SKB09H10 0200
No fault code found.
-------------------------------------------------------------------------------
Address 72: Door, Rear Right Labels: 4L0-910-795.lbl
Part No SW: 4L0 910 795 C HW: 4L0 959 794 C
Component: TSG HR H21 0150 Coding: 0000002 Shop #: WSC 31414 790 00001 VCID: 326B0980ADA3F5DA1B-8066
1 Fault Found:
02115 - Locking Unit for Central Locking
008 - Implausible Signal
Freeze Frame:
Fault Status: 01101000
Fault Priority: 3
Fault Frequency: 99
Reset counter: 183
Mileage: 171223 km
Time Indication: 0
Date: 2019.01.23
Time: 06:18:38
-------------------------------------------------------------------------------
Address 76: Park Assist Labels: 4Fx-910-283.lbl
Part No SW: 4F0 910 283 H HW: 4F0 919 283 H
Component: Parkhilfe 8-Kan H12 0080 Revision: 00H12000 Serial number: 06320721501491
Coding: 0221046 Shop #: WSC 31414 790 00001 VCID: 2959EEEC8075B602AA-807C
No fault code found.
-------------------------------------------------------------------------------
Address 77: Telephone Labels: 4E0-910-336.lbl
Part No SW: 4E0 910 336 K HW: 4E0 862 335
Component: Handyvorb2 H18 0950 Revision: 00000000 Serial number: 00000005006264
Coding: 0010900 Shop #: WSC 31414 790 00001 VCID: 2A5B11E08573BD1AA3-807E
No fault code found.
End-------------------------(Elapsed Time: 03:07)--------------------------Considering the low battery voltage readings, the consistent “Under-Voltage” fault codes, and the central locking issues, initiating an Audi Q7 battery change is a highly recommended first step. While the possibility of an ignition switch or other parasitic drain cannot be entirely ruled out without further investigation, a failing battery is a prime suspect and a common cause of such widespread electrical malfunctions in the Audi Q7. Replacing the battery will eliminate a significant potential problem source and provide a stable voltage foundation for further diagnosis if needed. If problems persist after a battery replacement, deeper electrical system checks would then be warranted.
