P0641 Sensor Reference Voltage “A” Circuit/Open

[Lombi]

I have a 2010 VW Jetta TDI

I’m getting a p0641 Sensor Reference Voltage “A” Circuit/Open
It’s not accompanied with any other fault codes.
Im wondering if anyone can tell me what sensors are on “A” group, or if all the sensors are.

I’ve already tried to individually unplug every sensor I can see in the engine compartment, to see if that code goes away. I have yet to have the code disappear. The car starts and runs fine, but unfortunately the car is in “limp” mode, so it can’t be driven. Does anyone have and idea of where to go next?

 

[NZDubNurd]

Post your complete autoscan and people will have a look.

 

[Lombi]

Thursday,19,November,2020,22:47:40:41986
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x64
VCDS Version: 20.4.2.0 (x64)  HEX-V2 CB: 0.4513.4
Data version: 20200730 DS317.0
www.Ross-Tech.com


VIN: 3VWAL7AJ2AM049272   License Plate: 


Chassis Type: AJ-VW36 (1K0)
Scan: 01 03 08 09 15 16 17 19 1C 25 42 44 46 52 56 62 65 72 77

VIN: 3VWAL7AJ2AM049272   Mileage: 255710km-158890miles

01-Engine -- Status: Malfunction 0010
03-ABS Brakes -- Status: Malfunction 0010
04-Steering Angle -- Status: OK 0000
08-Auto HVAC -- Status: Malfunction 0010
09-Cent. Elect. -- Status: Malfunction 0010
15-Airbags -- Status: Malfunction 0010
16-Steering wheel -- Status: OK 0000
17-Instruments -- Status: Malfunction 0010
19-CAN Gateway -- Status: OK 0000
1C-Position Sensing -- Status: OK 0000
25-Immobilizer -- Status: OK 0000
42-Door Elect, Driver -- Status: Malfunction 0010
44-Steering Assist -- Status: Malfunction 0010
46-Central Conv. -- Status: OK 0000
52-Door Elect, Pass. -- Status: Malfunction 0010
56-Radio -- Status: Malfunction 0010
62-Door, Rear Left -- Status: OK 0000
65-Tire Pressure -- Status: OK 0000
72-Door, Rear Right -- Status: OK 0000
77-Telephone -- Status: OK 0000
-------------------------------------------------------------------------------
Address 01: Engine (CJA)       Labels: 03L-906-022-CBE.clb
   Part No SW: 03L 997 030 L    HW: 03L 906 022 TS
   Component: R4 2.0l TDI G001SG  9983  
   Revision: 12H02---    Serial number:               
   Coding: 0050072
   Shop #: WSC 49915 001 104857
   VCID: 372B2F9DD347C493A39-8062

1 Fault Found:
001601 - Sensor Reference Voltage A 
               P0641 - 000 - Open Circuit - MIL ON
             Freeze Frame:
                    Fault Status: 11100000
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 255
                    Mileage: 255713 km
                    Time Indication: 0
                    Date: 2015.04.12
                    Time: 00:03:50

             Freeze Frame:
                    RPM: 0 /min
                    Speed: 0.0 km/h
                    Load: 0.0 %
                    Voltage: 12.24 V
                    Temperature: 13.5°C
                    (no units): 0.0
                    Torque: -150.0 Nm

Readiness: 0 0 0 1 1 

-------------------------------------------------------------------------------
Address 03: ABS Brakes (-----)       Labels:. 1K0-907-379-60EC1F.clb
   Part No SW: 1K0 907 379 AN    HW: 1K0 907 379 AN
   Component: ESP MK60EC1   H45 0107  
   Revision: 00H45001    
   Coding: 114B400C49260003880D02EB921B00423000
   Shop #: WSC 00066 000 00000
   VCID: 7EA5FAB9B0FD35DB20F-802A

6 Faults Found:
01314 - Engine Control Module 
            004 - No Signal/Communication - Intermittent
             Freeze Frame:
                    Fault Status: 00100100
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 75
                    Mileage: 255713 km
                    Time Indication: 0
                    Date: 2015.04.12
                    Time: 00:00:16

             Freeze Frame:
                    Count: 2
                    Count: 2
                    Count: 4608
                    Count: 8194
                    Count: 43776
                    Count: 0
                    Count: 0
                    Count: 0

01309 - Power Steering Control Module (J500) 
            004 - No Signal/Communication - Intermittent
             Freeze Frame:
                    Fault Status: 00100100
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 75
                    Mileage: 255713 km
                    Time Indication: 0
                    Date: 2015.04.12
                    Time: 00:08:07

             Freeze Frame:
                    Count: 2
                    Count: 2
                    Count: 256
                    Count: 8213
                    Count: 44032
                    Count: 0
                    Count: 0
                    Count: 0

00778 - Steering Angle Sensor (G85) 
            004 - No Signal/Communication - Intermittent
             Freeze Frame:
                    Fault Status: 00100100
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 75
                    Mileage: 255713 km
                    Time Indication: 0
                    Date: 2015.04.12
                    Time: 00:08:07

             Freeze Frame:
                    Count: 2
                    Count: 2
                    Count: 256
                    Count: 166
                    Count: 44032
                    Count: 0
                    Count: 0
                    Count: 0

01317 - Control Module in Instrument Cluster (J285) 
            004 - No Signal/Communication - Intermittent
             Freeze Frame:
                    Fault Status: 00100100
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 75
                    Mileage: 255713 km
                    Time Indication: 0
                    Date: 2015.04.12
                    Time: 00:08:07

             Freeze Frame:
                    Count: 2
                    Count: 2
                    Count: 256
                    Count: 8208
                    Count: 44032
                    Count: 0
                    Count: 0
                    Count: 0

01299 - Diagnostic Interface for Data Bus (J533) 
            004 - No Signal/Communication - Intermittent
             Freeze Frame:
                    Fault Status: 00100100
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 75
                    Mileage: 255713 km
                    Time Indication: 0
                    Date: 2015.04.12
                    Time: 00:08:07

             Freeze Frame:
                    Count: 2
                    Count: 0
                    Count: 256
                    Count: 8207
                    Count: 44032
                    Count: 0
                    Count: 0
                    Count: 0

01486 - System Function Test Activated 
            000 - -
             Freeze Frame:
                    Fault Status: 01100000
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 75
                    Mileage: 255714 km
                    Time Indication: 0
                    Date: 2015.04.12
                    Time: 01:13:12

             Freeze Frame:
                    Count: 3
                    Count: 2
                    Count: 4352
                    Count: 320
                    Count: 44032
                    Count: 0
                    Count: 0
                    Count: 0


-------------------------------------------------------------------------------
Address 08: Auto HVAC (J301)       Labels:| 3C8-907-336.clb
   Part No SW: 3C8 907 336 N    HW: 3C8 907 336 N
   Component: Climatic      H13 0203  
   Revision: 00008001    
   Coding: 0000000000
   Shop #: WSC 00066 000 00185
   ASAM Dataset: EV_Climatic A01001
   ROD: EV_ClimaBasis_VW36.rod
   VCID: 38292CA1D2D9CBEBAA3-806C

1 Fault Found:
13701376 - Function Restricted due to Missing Message(s) 
          U1111 00 [008] - -
          [Motorsteuergerät - kein Signal/Kommunikation]
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 115
                    Mileage: 255713 km
                    Date: 2020.11.19
                    Time: 00:00:17


-------------------------------------------------------------------------------
Address 09: Cent. Elect. (J519)       Labels:. 1K0-937-08x-09.clb
   Part No SW: 5K0 937 085 C    HW: 5K0 937 085 C
   Component: BCM PQ35 B++  008 6019  
   Revision: BI008001    
   Coding: 6D200B1A902F3EE4800800054000000401000086510085605C8020000000
   Shop #: WSC 49915 001 1048576
   VCID: 33331B8DCB3F28B39F1-8066

   Subsystem 1 - Part No: 1K1 955 119 E  Labels: 1KX-955-119.CLB
   Component: Wischer 14100  21  0501 
   Coding: 009795

3 Faults Found:
01495 - Bulb for High-Beams; Left (M30) 
            010 - Open or Short to Plus
             Freeze Frame:
                    Fault Status: 01101010
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 73
                    Mileage: 255712 km
                    Time Indication: 0
                    Date: 2015.04.05
                    Time: 00:47:48

             Freeze Frame:
                        Term 15 On
                    Voltage: 12.40 V
                        ON
                        ON
                        OFF
                        OFF
                        OFF

01499 - Bulb for High-Beams; Right (M32) 
            010 - Open or Short to Plus
             Freeze Frame:
                    Fault Status: 01101010
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 73
                    Mileage: 255712 km
                    Time Indication: 0
                    Date: 2015.04.05
                    Time: 00:47:48

             Freeze Frame:
                        Term 15 On
                    Voltage: 12.40 V
                        ON
                        ON
                        OFF
                        OFF
                        OFF

01504 - Bulb for License-Plate Light (X) 
            010 - Open or Short to Plus
             Freeze Frame:
                    Fault Status: 01101010
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 73
                    Mileage: 255712 km
                    Time Indication: 0
                    Date: 2015.04.05
                    Time: 00:47:48

             Freeze Frame:
                        Term 15 On
                    Voltage: 12.55 V
                        ON
                        ON
                        OFF
                        OFF
                        OFF


-------------------------------------------------------------------------------
Address 15: Airbags        Labels: 1K0-909-605.lbl
   Part No SW: 1K0 909 605 AD    HW: 1K0 909 605 AD
   Component: 04 AIRBAG VW8R  036 8900  
   Revision: 06036000    Serial number: 003EVM01C88D  
   Coding: 0012340
   Shop #: WSC 00066 000 00000
   VCID: 6E85CAF9EC9D455BB0F-803A

   Subsystem 1 - Part No: 1K0 959 339 H
   Component: BF-Gewichtsens. 007 0006

   Subsystem 2 - Serial number: 6332MSME4B402E017

   Subsystem 3 - Serial number: 6342MSME49507914B

   Subsystem 4 - Serial number: 6351HSME1D3642466

   Subsystem 5 - Serial number: 6361HSME1D36514FG

   Subsystem 6 - Serial number: 63727SME00115D4E+

   Subsystem 7 - Serial number: 63827SME00130467P

1 Fault Found:
01316 - ABS Control Module 
            004 - No Signal/Communication - Intermittent

-------------------------------------------------------------------------------
Address 16: Steering wheel        Labels: 1K0-953-549-MY9.lbl
   Part No SW: 1K0 953 549 CD    HW: 1K0 953 549 CD
   Component: J0527           056 0111  
   Coding: 0000731
   Shop #: WSC 00066 000 00000
   VCID: 76B5E29994CD7D9B78F-8022

   Subsystem 1 - Part No: 5K0 959 542   Labels: 3C8-959-537.CLB
   Component: E221__MFL-TAS   H05 0010  
   Coding: 00000130
   Shop #: WSC 00000  

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments (J285)       Labels:| 5K0-920-xxx-17.clb-SRI1
   Part No SW: 5M0 920 970 C    HW: 5M0 920 970 C
   Component: KOMBI         H08 0021  
   Revision: V0008011    Serial number:               
   Coding: 271F00
   Shop #: WSC 00066 000 00150
   ASAM Dataset: EV_KombiUDSMM9RM10 A04010
   ROD: EV_KombiUDSMM9RM10_A04_VW36.rod
   VCID: 303914813AA913ABE23-8064

5 Faults Found:
13701120 - Function Restricted due to Interrupted Communications 
          U1110 00 [008] - -
          [BAP: Funktionseinschränkung wegen Kommunikationsstörung]
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 5
                    Reset counter: 115
                    Mileage: 0 km
                    Date: 2000.00.00
                    Time: 00:00:00

12648448 - Function Restricted due to Missing Message(s) 
          U1111 00 [008] - -
          [Steuergerät für Motor: keine Kommunikation]
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 2
                    Reset counter: 115
                    Mileage: 255713 km
                    Date: 2020.11.19
                    Time: 00:00:13

12656896 - Function Restricted due to Missing Message(s) 
          U1111 00 [008] - -
          [Steuergerät für Bremse: keine Kommunikation]
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 115
                    Mileage: 255713 km
                    Date: 2020.11.19
                    Time: 00:08:06

12669184 - Function Restricted due to Missing Message(s) 
          U1111 00 [008] - -
          [Steuergerät für Airbag: keine Kommunikation]
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 115
                    Mileage: 255713 km
                    Date: 2020.11.19
                    Time: 00:08:06

13638912 - Function Restricted due to Missing Message(s) 
          U1111 00 [008] - -
          [Steuergerät für Lenkhilfe: keine Kommunikation]
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 115
                    Mileage: 255713 km
                    Date: 2020.11.19
                    Time: 00:08:06


-------------------------------------------------------------------------------
Address 19: CAN Gateway        Labels:. 1K0-907-530-V4.clb
   Part No SW: 1K0 907 530 AA    HW: 1K0 907 951 
   Component: J533  Gateway   H07 0081  
   Revision:   H07 01    Serial number: 130809F2001563
   Coding: E9807F07001602001002
   Shop #: WSC 00066 000 00000
   VCID: 6695B2D9C46D8D1BC8F-8032

No fault code found.

-------------------------------------------------------------------------------
Address 1C: Position Sensing        Labels: 1Kx-919-xxx-1C.lbl
   Part No SW: 1K5 919 965 D    HW: 1K5 919 965 D
   Component: Kompass         001 0001  
   Revision: 00001000    Serial number: 1293324T4F5005
   Coding: 0000004
   Shop #: WSC 00066 000 00000
   VCID: 3C2130B1EA61E7CB4EB-8068

No fault code found.

-------------------------------------------------------------------------------
Address 25: Immobilizer (J334)       Labels:. 5K0-920-xxx-25.clb
   Part No SW: 5M0 920 970 C    HW: 5M0 920 970 C
   Component: IMMO          H08 0021  
   Revision: V0008011    Serial number:               
   Shop #: WSC 00000 000 00000
   ASAM Dataset: EV_ImmoUDSMM9RM10 A01010
   ROD: EV_ImmoUDSMM9RM10_VW12.rod
   VCID: 303914813AA913ABE23-8064

No fault code found.

-------------------------------------------------------------------------------
Address 42: Door Elect, Driver        Labels:. 1K0-959-701-MIN3.clb
   Part No SW: 1K0 959 701 AC    HW: 1K0 959 793 N
   Component: J386  TUER-SG FT    1525  
   Revision: 72009005    Serial number: 00000515498921
   Coding: 0001205
   Shop #: WSC 00066 000 00000
   VCID: 6FBBD7FDEB974C53BB9-803A

1 Fault Found:
00932 - Electric Window Motor; Drivers Side (V147) 
            005 - No or Incorrect Basic Setting / Adaptation
             Freeze Frame:
                    Fault Status: 01100101
                    Fault Priority: 6
                    Fault Frequency: 1
                    Reset counter: 75
                    Mileage: 0 km
                    Time Indication: 0


-------------------------------------------------------------------------------
Address 44: Steering Assist        Labels: 1K0-909-14x-GEN3.clb
   Part No: 1K0 909 144 H
   Component: EPS_ZFLS Kl. 70     2901  
   Revision: 00H17000    
   Shop #: WSC 02069 000 90108
   VCID: 2F3B17FD2B170C53FB9-807A

1 Fault Found:
03803 - Steering Angle Sensor for Steering Aid 
            000 - - - MIL ON
             Freeze Frame:
                    Fault Status: 11100000
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 255
                    Time Indication: 0

             Freeze Frame:
                    Battery Volts: 12.7 V
                        PD
                    Temperature: 15.0°C
                    Count: 2
                    Steering Angle: 0.00°
                    Count: 1
                        SteerAng n.Init


-------------------------------------------------------------------------------
Address 52: Door Elect, Pass.        Labels:. 1K0-959-702-MIN3.clb
   Part No SW: 1K0 959 702 AC    HW: 1K0 959 792 N
   Component: J387  TUER-SG BT    1525  
   Revision: 72009005    Serial number: 09071820465304
   Coding: 0001204
   Shop #: WSC 00066 000 00000
   VCID: 70B9D481F6A953ABA23-8024

3 Faults Found:
01553 - Motor for Central Locking; Passenger Door (V57); Lock 
            012 - Electrical Fault in Circuit - Intermittent
             Freeze Frame:
                    Fault Status: 00101100
                    Fault Priority: 3
                    Fault Frequency: 7
                    Reset counter: 115
                    Mileage: 255712 km
                    Time Indication: 0
                    Date: 2015.04.11
                    Time: 02:15:11

00929 - Locking Module for Central Locking; Front Passenger Side (F221) 
            008 - Implausible Signal
             Freeze Frame:
                    Fault Status: 01111000
                    Fault Priority: 3
                    Fault Frequency: 1
                    Reset counter: 75
                    Mileage: 255712 km
                    Time Indication: 0
                    Date: 2015.04.11
                    Time: 02:15:11

00110 - Right Mirror Turn Signal Lamp (L132) 
            012 - Electrical Fault in Circuit - Intermittent
             Freeze Frame:
                    Fault Status: 00101100
                    Fault Priority: 5
                    Fault Frequency: 1
                    Reset counter: 115
                    Mileage: 255712 km
                    Time Indication: 0
                    Date: 2015.04.11
                    Time: 02:09:03


-------------------------------------------------------------------------------
Address 56: Radio (J503)       Labels:. 5M0-035-1xx-56.clb
   Part No SW: 1K0 035 180 AC    HW: 1K0 035 180 AC
   Component: Radio Prem-8  H13 0044  
   Revision: -----26S    Serial number: VWZ4Z7K3130741
   Coding: 0500040004
   Shop #: WSC 08396 444 131545
   VCID: 619FA1C52143EA233DD-8034

1 Fault Found:
02635 - Tuner Not Enabled/Activated 
            000 - -
             Freeze Frame:
                    Fault Status: 01100000
                    Fault Priority: 7
                    Fault Frequency: 2
                    Reset counter: 75
                    Mileage: 255712 km
                    Time Indication: 0
                    Date: 2015.04.04
                    Time: 12:36:15


-------------------------------------------------------------------------------
Address 62: Door, Rear Left        Labels:. 1K0-959-703-GEN3.clb
   Part No SW: 1K0 959 703 AH    HW: 1K0 959 795 T
   Component: J388   TUER-SG HL   1401  
   Revision: 12006001    Serial number: 00000004287096
   Coding: 0001168
   Shop #: WSC 00066 000 00000
   VCID: 76B5E29994CD7D9B78F-8022

No fault code found.

-------------------------------------------------------------------------------
Address 65: Tire Pressure (J502)       Labels:. 1K0-937-08x-65.clb
   Part No SW: 5K0 937 085 C    HW: 5K0 937 085 C
   Component: RDK           008 0817  
   Coding: 018705
   Shop #: WSC 00066 000 00000
   VCID: 33331B8DCB3F28B39F1-8066

No fault code found.

-------------------------------------------------------------------------------
Address 72: Door, Rear Right        Labels:. 1K0-959-704-GEN3.clb
   Part No SW: 1K0 959 704 AH    HW: 1K0 959 794 T
   Component: J389   TUER-SG HR   1401  
   Revision: 12006001    Serial number: 00000004299898
   Coding: 0001168
   Shop #: WSC 00066 000 00000
   VCID: 77ABEF9D93C70493639-8022

No fault code found.

-------------------------------------------------------------------------------
Address 77: Telephone        Labels: 5P0-862-335.lbl
   Part No SW: 1Z0 035 729 C    HW: 1Z0 035 729 C
   Component: FSE_2P8x        H35 0170  
   Revision: 00000000    Serial number: 00000005067783
   Coding: 0011070
   Shop #: WSC 00066 000 00000
   VCID: 38292CA1DE59CBEBAA3-806C

No fault code found.

End----------(Elapsed Time: 01:24, VBatt start/end: 12.3V/12.2V)-----------

 

[Uwe]

I’ve already tried to individually unplug every sensor I can see in the engine compartment, to see if that code goes away.

Unplugging sensors is unlikely to change an "Open Circuit" fault.

You're going to need a wiring diagram.

-Uwe-

 

[Lombi]

Unplugging sensors is unlikely to change an "Open Circuit" fault.

You're going to need a wiring diagram.

-Uwe-

i have a full diagram.

 

[PetrolDave]

i have a full diagram.

You'll need to use it to trace which wire has an open circuit.

 

[Bruce]

Could also be the refernce voltage from the ECU is Kaput! VOM (Volt Ohm Meter) is your friend for this case.

 

[Lombi]

You'll need to use it to trace which wire has an open circuit.

im aware of having to trace every single wire... Thats why i asked if anyone knew if all sensors are on group "a" or if curtain sensors were.

 

[Lombi]

Does anyone know where to find a wiring pin-out of the ECU? like i said, i have a full wiring diagram but it doesnt show me which wires are 5v ref wires

 

[Bruce]

Does anyone know where to find a wiring pin-out of the ECU? like i said, i have a full wiring diagram but it doesnt show me which wires are 5v ref wires

Should be clearly shown on the wiring diagram. The sensor has a few pins. Follow the tracks on the diagram leading back to the pins used to connect that sensor.

Need help understanding how to read the wiring diagrams? View this video: