Good day,

Is there a way to see if anything is 'cooking' DTC wise in say the ECU? Eg. some fault is tripping yet hasn't gone past a pre-set fault frequency to generate a propper DTC? Being able to peak 'inside' for such activity would be neato.

Cheers & Happy Holidays if you're into that sort of thing,
Grant

If curious, below is what happened + a full auto-scan (once a DTC showed up)
================================================== ============
Last week my '15 Passat TDI briefly ran like the old old firetruck in the first Disney Cars movie. Small children on their plastic big wheels were passing me on the sidewalk. However by the time I made it through the intersection (and finished thinking... call tow truck, insurance, maybe take morning off work) everything was fine.

Long & short, only after two weeks and a couple tanks of fuel did I finally get a CEL with DTC.


Code:
VIN: 1VWCV7A38FC0XXXXX   License Plate: OREGON
Mileage: 144980km-90086mi   Repair Order: 121719Ax



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


Chassis Type: A3-VW41 (7N0)
Scan: 01 02 03 05 08 09 15 16 17 19 25 2B 2E 36 37 42 44 46 47 4F
          52 56 62 72 75 77

VIN: 1VWCV7A38FC0XXXXX   Mileage: 144980km-90086miles

01-Engine -- Status: Malfunction 0010
02-Auto Trans -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
04-Steering Angle -- Status: OK 0000
05-Acc/Start Auth. -- Status: OK 0000
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- 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
2B-Steer. Col. Lock -- Status: OK 0000
2E-Media Player 3 -- Status: OK 0000
36-Seat Mem. Drvr -- Status: OK 0000
37-Navigation -- Status: OK 0000
42-Door Elect, Driver -- Status: OK 0000
44-Steering Assist -- Status: OK 0000
46-Central Conv. -- Status: OK 0000
47-Sound System -- Status: OK 0000
4F-Centr. Electr. II -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
56-Radio -- Status: OK 0000
62-Door, Rear Left -- Status: OK 0000
72-Door, Rear Right -- Status: OK 0000
75-Telematics -- Status: OK 0000
77-Telephone -- Status: OK 0000
-------------------------------------------------------------------------------
Address 01: Engine (J623-CVCA)       Labels:. 04L-907-309-V1.clb
   Part No SW: 04L 997 016 D    HW: 04L 907 309 K
   Component: R4 2.0l TDI   X20 9466  
   Revision: 8AX20---    
   Coding: 011D0012032410089000
   Shop #: WSC 23048 444 00200
   ASAM Dataset: EV_ECM20TDI01104L997016D 004002
   ROD: EV_ECM20TDI01104L997016D.rod
   VCID: 3431E0213EB1E6571DF-8060

1 Fault Found:
21467 - Mass Airflow Sensor 1 
          P00BC 00 [236] - Airflow too Low
          MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 7
                    Mileage: 144972 km
                    Date: 2019.12.17
                    Time: 00:39:53

                    Engine speed: 1354.50 /min
                    Normed load value: 76.9 %
                    Vehicle speed: 79 km/h
                    Coolant temperature: 59 C
                    Intake air temperature: 46 C
                    Ambient air pressure: 1010 mbar
                    Voltage terminal 30: 13.820 V
                    Unlearning counter according OBD: 40
                    Mass airflow sensor 1 bank 1 airflow: raw value: 469.5 mg/stroke
                    Standardized airflow ratio: filtered: 1.3478
                    Exhaust recirc.valve 1 bank 1: posit.feedback - Act.value: 0.00 %
                    Throttl.valve adapt. 1 bank 1: posit feedback - Act.value: 0.16 %
                    Charge air pressure specified value: 1399 hPa
                    Charge air cooler inlet: pressure sensor 1 bank 1: raw value: 1397.6 hPa
                    Mean injection quantity: 27.71 mg/stroke

Readiness: 1 1 0 0 0 

-------------------------------------------------------------------------------
Address 02: Auto Trans        Labels: User\02E-927-770.clb
   Part No SW: 02E 300 061 T    HW: 02E 927 770 AL
   Component: GSG DSG AG6     521 4518  
   Revision: 05652104    Serial number: 00001407100202
   Coding: 0000024
   Shop #: WSC 09003 957 00200
   VCID: 25170D6589EB8FDF9A1-8070

No fault code found.

-------------------------------------------------------------------------------
Address 03: ABS Brakes (J104)       Labels:. 1K0-907-379-60EC1F.clb
   Part No SW: 1K0 907 379 BM    HW: 1K0 907 379 BM
   Component: ESP MK60EC1   H46 0164  
   Revision: 00H46001    
   Coding: C54BC0F549240002A30C03EB92210042A1100012
   Shop #: WSC 09003 957 00200
   VCID: 7EA5020940FDFC07BBB-802A

No fault code found.

-------------------------------------------------------------------------------
Address 05: Acc/Start Auth. (J518)       Labels:| 5K0-959-434.clb
   Part No SW: 5K0 959 434 E    HW: 5K0 959 434 
   Component: VWKESSYPQ35GP 092 1202  
   Revision: 00092000    Serial number: 0341828660
   Coding: 130C0C
   Shop #: WSC 09003 957 00200
   ASAM Dataset: EV_KESSYPQ35G A02717
   ROD: EV_KESSYPQ35G_A02_VW31.rod
   VCID: 372BD72D2FC70D4F38D-8062

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC (J255)       Labels:| 5K0-907-044.clb
   Part No SW: 561 907 044 AP    HW: 561 907 044 AP
   Component: Climatronic   H03 0707  
   Revision: 00001K01    
   Coding: 0010019012
   Shop #: WSC 09003 957 00200
   ASAM Dataset: EV_ACClimaBHBVW411 A01001
   ROD: EV_ACClimaBHBVW411_VW41.rod
   VCID: 65974D65C5EB4FDF5A1-8030

No fault code found.

-------------------------------------------------------------------------------
Address 09: Cent. Elect. (J519)       Labels:. 1K0-937-08x-09.clb
   Part No SW: 5K0 937 087 AE    HW: 5K0 937 087 AE
   Component: BCM PQ35 H+   122 0174  
   Revision: BL122001    
   Coding: EF200E3BF86B28D409A80201360081C002F1A0B845A005B064806000BC70
   Shop #: WSC 09003 957 00200
   VCID: 78A9141162D9C237F17-802C

   Subsystem 1 - Part No: 1K0 955 559 AH  Labels: 1K0-955-559-AG.CLB
   Component: RLS 020814 05  54  0403 
   Coding: 0630CD

No fault code found.

-------------------------------------------------------------------------------
Address 15: Airbags (J234)       Labels:| 5K0-959-655.clb
   Part No SW: 5C0 959 655 AA    HW: 5C0 959 655 AA
   Component: AirbagVW10    500 0975  
   Serial number: 003LYD0165TQ  
   Coding: 00004D52
   Shop #: WSC 63966 001 1048576
   ASAM Dataset: EV_AirbaVW10SMEVW360 001030
   ROD: EV_AirbaVW10SMEVW360.rod
   VCID: 71BF29350123937F369-8024

   Seat occupied recognition: 
   Subsystem 1 - Part No SW: 5C6 959 339 B    HW: 5C6 959 339 B
   Component: BF-Gewichtss.  H10 0046 
   Serial number: 6940000Y1400017T2X01
   Coding: 303047

   Crash sensor for side airbag: driver side: 
   Subsystem 2 - Part No SW: 5K0 959 354     HW: 5K0 959 354 
   Component: S.Sens.Fahr.V  H02 ---- 
   Serial number: 3572MSME3C696B47ZZZ8

   Crash sensor for side airbag: front passenger side: 
   Subsystem 3 - Part No SW: 5K0 959 354     HW: 5K0 959 354 
   Component: S.Sens.Beif.V  H02 ---- 
   Serial number: 3582MSME7E676B47ZZZD

   Crash sensor for side airbag: rear: driver side: 
   Subsystem 4 - Part No SW: 5K0 959 351 A    HW: 5K0 959 351 A
   Component: S.Sens.Fahr.H  H02 ---- 
   Serial number: 3516KSME280D3E2FZZZ3

   Crash sensor for side airbag: rear: passenger side: 
   Subsystem 5 - Part No SW: 5K0 959 351 A    HW: 5K0 959 351 A
   Component: S.Sens.Beif.H  H02 ---- 
   Serial number: 3526KSME57153F2FZZZ0

   Crash sensor for front airbag: driver side: 
   Subsystem 6 - Part No SW: 5K0 959 659 A    HW: 5K0 959 659 A
   Component: F.Sens.Fahr  H02 ---- 
   Serial number: 3556LSME106E0430ZZZM

   Crash sensor for front airbag: front passenger side: 
   Subsystem 7 - Part No SW: 5K0 959 659 A    HW: 5K0 959 659 A
   Component: F.Sens.Beif  H02 ---- 
   Serial number: 3566LSME3D450430ZZZR

No fault code found.

-------------------------------------------------------------------------------
Address 16: Steering wheel (J527)       Labels:| 5K0-953-569.clb
   Part No SW: 1K5 953 521 BR    HW: 5K0 953 569 AH
   Component: LENKS.MODUL   016 0140  
   Revision: FF010042    Serial number: 20140728200240
   Coding: 000A140000
   Shop #: WSC 09003 957 00200
   ASAM Dataset: EV_SMLSNGVOLWSXS A01004
   ROD: EV_SMLSNGVOLWS.rod
   VCID: 7EA50209407DFC07BBB-802A

   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-YVJ  H07 0023 
   Coding: E20000

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments (J285)       Labels:| 5K0-920-XXX-17.clb-SRI1
   Part No SW: 561 920 970 G    HW: 561 920 970 G
   Component: KOMBI         H04 0813  
   Serial number: 00000000000000
   Coding: 231C01
   Shop #: WSC 09003 957 00200
   ASAM Dataset: EV_Kombi_UDS_VDD_RM09 A04723
   ROD: EV_Kombi_UDS_VDD_RM09_004_VW32.rod
   VCID: 1E652289A03D5C07DBB-804A

No fault code found.

-------------------------------------------------------------------------------
Address 19: CAN Gateway (J533)       Labels:. 7N0-907-530-V2.clb
   Part No SW: 7N0 907 530 AR    HW: 7N0 907 530 AM
   Component: J533  Gateway H55 1653  
   Revision:   H55       Serial number: 28081403001306
   Coding: 461000
   Shop #: WSC 09003 957 00200
   VCID: 00597CF13A098AF7C97-8054

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          H04 0813  
   Serial number:               
   Coding: 000007
   Shop #: WSC 09003 957 00200
   ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03710
   ROD: EV_Immo_UDS_VDD_RM09.rod
   VCID: 6A8D3E592CF560A7773-803E

No fault code found.

-------------------------------------------------------------------------------
Address 2B: Steer. Col. Lock (J764)       Labels:* 5K0-905-861.clb
   Part No SW: 5K0 905 861 C    HW: 5K0 905 861 C
   Component: ELV-PQ35      H21 0240  
   Revision: 00000000    Serial number: 14000174117002
   Coding: 4900000000000000
   Shop #: WSC 09003 957 00200
   ASAM Dataset: EV_ELVMarquMPVW36X A01001
   ROD: EV_ELVMarquMPVW36X.rod
   VCID: 3039EC31CAA9DA77797-8064

No fault code found.

-------------------------------------------------------------------------------
Address 2E: Media Player 3
Cannot be reached

-------------------------------------------------------------------------------
Address 36: Seat Mem. Drvr (J136)       Labels: None
   Part No SW: 561 959 760 B    HW: 561 959 760 B
   Component: MEM-FS        H04 0182  
   Revision: AA000000    Serial number: 00000111333537
   Coding: 00581B0000000000000021010100202020202120202020
   Shop #: WSC 09003 957 00200
   VCID: 221D167994C578E7FF3-8076

No fault code found.

-------------------------------------------------------------------------------
Address 37: Navigation (J0506)       Labels:. 1T0-035-680.clb
   Part No SW: 3C0 035 684 R    HW: 3C0 035 684 P
   Component: RNS-MID       H30 5382  
   Revision: AB001001    Serial number: VWZ6Z7U0236003
   Coding: 04090042010000A2000B
   Shop #: WSC 13109 408 00200
   VCID: 323DE639C425E8670F3-8066

   Subsystem 1 - Part No: 7L6 919 859 
   Component: NAR V12  8534 

No fault code found.

-------------------------------------------------------------------------------
Address 42: Door Elect, Driver (J386)       Labels:| 3C0-959-70X-GEN4.clb
   Part No SW: 561 959 701 A    HW: 3C0 959 793 C
   Component: TUER-SG FT    002 0525  
   Revision: 12110009    Serial number: 0008844439
   Coding: 0405FD
   Shop #: WSC 09003 957 00200
   ASAM Dataset: EV_TSGFPQ25BRFVW46X A04001
   ROD: EV_TSGFPQ25BRFVW46X.rod
   VCID: 1C612881B6214E1735F-8048

   Slave Driver: 
   Subsystem 1 - Part No SW: 561 959 811 B    HW: 561 959 811 B  Labels: 1K0-959-70X-GEN4.CLB
   Component: J388__TSG_HL  006 5470 
   Serial number: 14202630140825185201
   Coding: 800000

No fault code found.

-------------------------------------------------------------------------------
Address 44: Steering Assist        Labels: 1K0-909-14x-GEN3.clb
   Part No: 1K0 909 144 R
   Component: EPS_ZFLS Kl. 215    3501  
   Revision: 00H22000    
   Shop #: WSC 01357 011 00200
   VCID: 392FD11515531B3FCE9-806C

No fault code found.

-------------------------------------------------------------------------------
Address 47: Sound System (R12)       Labels: 5K0-035-456.clb
   Part No SW: 5C6 035 456 A    HW: 5C6 035 456 A
   Component: KonzernAmp10K H08 6815  
   Revision: --------    Serial number: EAA098A0162059
   ASAM Dataset: EV_AudioVerst10KanalSTT3 S01001
   ROD: EV_AudioVerst10KanalSTT3.rod
   VCID: 26150A69F86D84C793B-8072

No fault code found.

-------------------------------------------------------------------------------
Address 4F: Centr. Electr. II (J520)       Labels:. 1K0-907-532.clb
   Part No SW: 7N0 907 532     HW: 7N0 907 530 AM
   Component: EZE_2         H55 1653  
   Revision:   H55       Serial number: 28081403001306
   Coding: 01030108
   Shop #: WSC 09003 957 00200
   VCID: 6FBB2F4D1797858F20D-803A

   Subsystem 1 - Part No SW: 561 959 591 A    HW: 561 959 591 A
   Component: J245 P05 9BA3  H08 0005 
   Serial number: 53388786011334903288
   Coding: 181100

   Subsystem 2 - Part No SW: 561 919 204 B    HW: 561 919 204 B
   Component: Analoguhr  008 0005 

No fault code found.

-------------------------------------------------------------------------------
Address 52: Door Elect, Pass. (J387)       Labels:| 3C0-959-70X-GEN4.clb
   Part No SW: 561 959 702 A    HW: 3C0 959 792 C
   Component: TUER-SG BT    002 0525  
   Revision: 14110009    Serial number: 0008817542
   Coding: 0405FC
   Shop #: WSC 09003 957 00200
   ASAM Dataset: EV_TSGBPQ25BRFVW46X A04001
   ROD: EV_TSGBPQ25BRFVW46X.rod
   VCID: 1D672585AD3B471FC21-8048

   Slave Passenger: 
   Subsystem 1 - Part No SW: 561 959 812 B    HW: 561 959 812 B  Labels: 1K0-959-70X-GEN4.CLB
   Component: J389__TSG_HR  006 5470 
   Serial number: 14202631140908144323
   Coding: 800000

No fault code found.

-------------------------------------------------------------------------------
Address 56: Radio (J0506)       Labels:. 1T0-035-680.clb
   Part No SW: 3C0 035 684 R    HW: 3C0 035 684 P
   Component: RNS-MID       H30 5382  
   Revision: AB001001    Serial number: VWZ6Z7U0236003
   Coding: 04090042010000A2000B
   Shop #: WSC 13109 408 00200
   VCID: 323DE639C425E8670F3-8066

   Subsystem 1 - Part No: 7L6 919 859 
   Component: NAR V12  8534 

No fault code found.

-------------------------------------------------------------------------------
Address 75: Telematics (J949)       Labels:| 12E-035-284.clb
   Part No SW: 561 035 285     HW: 561 035 285 
   Component: OCULowUSA     014 0102  
   Serial number: 000003554140526
   Coding: 02140102C2423A00000000000000
   Shop #: WSC 09003 957 00200
   ASAM Dataset: EV_OCULow 001010
   ROD: EV_OCULow_001.rod
   VCID: 53F383BD9B7FC16F245-8006

1 Fault Found:
2103041 - Control Module 
          B1788 F0 [009] - Start Prohibition Deactivated
          Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 8
                    Fault Frequency: 1
                    Reset counter: 130
                    Mileage: 144981 km
                    Date: 2019.12.17
                    Time: 00:54:50


-------------------------------------------------------------------------------
Address 77: Telephone (J412)       Labels:| 5N0-035-729.clb
   Part No SW: 5N0 035 729 A    HW: 5N0 035 729 A
   Component: TELEFON       H05 0592  
   Revision: 1B001001    Serial number: 00007666098421
   Coding: 0A10030080010110
   Shop #: WSC 09003 957 00200
   ASAM Dataset: EV_UHVUMI 001007
   ROD: EV_UHVUMI.rod
   VCID: 2E05F249D09DCC876BB-807A

No fault code found.

End----------(Elapsed Time: 01:21, VBatt start/end: 12.6V/12.5V)-----------

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


                Address 01: Engine       Labels: 04L-907-309-V1.clb
Control Module Part Number: 04L 997 016 D    HW: 04L 907 309 K
  Component and/or Version: R4 2.0l TDI   X20 9466
           Software Coding: 011D0012032410089000
            Work Shop Code: WSC 23048 444 00200
              ASAM Dataset: EV_ECM20TDI01104L997016D 004002 (VW41)
                       ROD: EV_ECM20TDI01104L997016D.rod
                      VCID: 3431E0213EB1E6571DF-8060
1 Fault Found:

21467 - Mass Airflow Sensor 1 
          P00BC 00 [236] - Airflow too Low
          MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 7
                    Mileage: 144972 km
                    Date: 2019.12.17
                    Time: 00:39:53

                    Engine speed: 1354.50 /min
                    Normed load value: 76.9 %
                    Vehicle speed: 79 km/h
                    Coolant temperature: 59 C
                    Intake air temperature: 46 C
                    Ambient air pressure: 1010 mbar
                    Voltage terminal 30: 13.820 V
                    Unlearning counter according OBD: 40
                    Mass airflow sensor 1 bank 1 airflow: raw value: 469.5 mg/stroke
                    Standardized airflow ratio: filtered: 1.3478
                    Exhaust recirc.valve 1 bank 1: posit.feedback - Act.value: 0.00 %
                    Throttl.valve adapt. 1 bank 1: posit feedback - Act.value: 0.16 %
                    Charge air pressure specified value: 1399 hPa
                    Charge air cooler inlet: pressure sensor 1 bank 1: raw value: 1397.6 hPa
                    Mean injection quantity: 27.71 mg/stroke


Readiness: 1 1 0 0 0