Clearing camshaft code fixes rough idle for 2 to 5 seconds. What???

   #1  

precursor

Verified VCDS User
Verified
Joined
Jul 7, 2021
Messages
9
Reaction score
8
Location
Midwest, USA
VCDS Serial number
C?ID=433554
First: I will post a complete Autoscan if necessary, but at present the car has enough battery-related codes and random nonsense that I think it will only muddy the waters.

I've been trying to run down the reason for intermittent periods of extremely rough, jerky idle on my 2005 A6 3.2, often beginning 10 minutes or so after starting the car, but occasionally presenting on cold start. Leading candidates were engine mounts, fuel pump, fouled injectors, or timing chain issues.

In the course of testing ideas, I found that the oil was overfilled, so I drained it down to acceptable levels. I then started the car and ran it a bit, and cleared the codes to see what would come back. I noticed that the car had a few seconds of perfect idle as I cleared the codes, but I thought nothing of it.

The only engine code that reappeared was:

Camshaft Position Sensor B Bank 1 (G300)
P0366-006 Implausible Signal

I cleared it again, just to make sure it was going to stick. This time, something really struck me: I got 2 or 3 seconds of buttery-smooth idle, the very instant I cleared the code. Then rough idle and code reappeared simultaneously.

I tested it again and again. Worked every time: I would without fail get between 2 and 5 seconds of perfect idle every time I cleared that code.

This goes against my understanding of how the codes work. I thought they were just messages to help the mechanic. I didn't think that clearing them could do anything meaningful to how the car actually ran. I figured that was where coding and testing came in.

Based on what I described, does anyone have any ideas of what is going on here? Does my ability to (briefly) achieve perfect idle by clearing that code point to the source of my idle problems?

Thanks!
 
Last edited:
   #2  

PetrolDave

Verified VCDS User
Verified
Joined
Dec 16, 2014
Messages
4,921
Reaction score
4,934
Location
Trowbridge, UK
VCDS Serial number
C?ID=1423
I suggest you do a clear all codes to get rid of irrelevant historical ones, then do another auto-scan and post it here so we can see not only the fault codes but how your car is equipped.
 
   #3  

precursor

Verified VCDS User
Verified
Joined
Jul 7, 2021
Messages
9
Reaction score
8
Location
Midwest, USA
VCDS Serial number
C?ID=433554
Scan from today:

Code:
Tuesday,21,September,2021,07:39:30:45339
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x64
VCDS Version: 21.9.0.2 (x64)  HEX-V2 CB: 0.4555.4
Data version: 20210903 DS330.0
www.Ross-Tech.com


VIN: WAUDG74F75N072759   License Plate: BL
Mileage: 247530km-153808mi   Repair Order: 



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


Chassis Type: 4F (4F0)
Scan: 01 02 03 05 07 08 09 0E 0F 15 16 17 19 36 42 46 47 4F 52 53
          55 56 61 62 72 77

VIN: WAUDG74F75N072759   Mileage: 247530km-153808miles

00-Steering Angle Sensor -- Status: OK 0000
01-Engine -- Status: Malfunction 0010
02-Auto Trans -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
05-Acc/Start Auth. -- Status: Malfunction 0010
07-Control Head -- Status: OK 0000
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- Status: OK 0000
0E-Media Player 1 -- Status: OK 0000
0F-Digital Radio -- Status: Malfunction 0010
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: Malfunction 0010
36-Seat Mem. Drvr -- Status: OK 0000
42-Door Elect, Driver -- Status: OK 0000
46-Central Conv. -- Status: Malfunction 0010
47-Sound System -- Status: OK 0000
4F-Centr. Electr. II -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
53-Parking Brake -- Status: OK 0000
55-Headlight Range -- Status: OK 0000
56-Radio -- Status: OK 0000
61-Battery Regul. -- Status: Malfunction 0010
62-Door, Rear Left -- Status: OK 0000
72-Door, Rear Right -- Status: OK 0000
77-Telephone -- Status: OK 0000
-------------------------------------------------------------------------------
Address 01: Engine (AUK)       Labels:. 06E-910-559-BKH.clb
   Part No SW: 4F1 910 559 B    HW: 4F1 907 559 A
   Component: 3.2l V6 FSI         0040  
   Revision: --H15---    Serial number:               
   Coding: 01050106190F0120
   Shop #: WSC 02325 785 00200
   VCID: 2A0D0884C0F438EBD95-807E
   VINID: 9D19545C71161C57801C21C52477045136

2 Faults Found:
16750 - Camshaft Position Sensor B Bank 1 (G300) 
            P0366 - 006 - Implausible Signal - MIL ON
             Freeze Frame:
                    Fault Status: 11100001
                    Fault Priority: 4
                    Fault Frequency: 3
                    Reset counter: 40
                    Mileage: 247533 km
                    Time Indication: 0
                    Date: 2021.09.20
                    Time: 17:43:16

             Freeze Frame:
                    RPM: 864 /min
                    Mass Air / Rev.: 92.7 mg/str
                    Temperature: 70.5°C
                        Idle
                    Bin. Bits: 00010000
                    Speed: 0.0 km/h

18975 - Low Pressure Fuel Sensor (G410) 
            P2543 - 009 - Intermittent
             Freeze Frame:
                    Fault Status: 00100100
                    Fault Priority: 2
                    Fault Frequency: 2
                    Reset counter: 40
                    Mileage: 247533 km
                    Time Indication: 0
                    Date: 2021.09.20
                    Time: 17:43:30

             Freeze Frame:
                    RPM: 704 /min
                    Mass Air / Rev.: 207.1 mg/str
                    Temperature: 69.0°C
                        Idle
                    Pressure: 4.9 bar
                    Speed: 0.0 km/h

Readiness: 0110 0101

-------------------------------------------------------------------------------
Address 02: Auto Trans        Labels: 09L-927-760.lbl
   Part No SW: 4F1 910 156 H    HW: 09L 927 156 
   Component: AG6 09L 3.2 FSI USA 0020  
   Revision: --H01---    Serial number:        0068901
   Coding: 0001002
   Shop #: WSC 02327 785 00200
   VCID: 290FF788C5F233F3D0F-807C

No fault code found.

-------------------------------------------------------------------------------
Address 03: ABS Brakes        Labels: 4F0-910-517.clb
   Part No SW: 4F0 910 517 E    HW: 4F0 614 517 A
   Component: ESP8 quattro    H03 0010  
   Revision: 00000000    Serial number: 00000000000000
   Coding: 0020895
   Shop #: WSC 02327 785 00200
   VCID: 2615FCB4D4EC1C8BFDD-8072

No fault code found.

-------------------------------------------------------------------------------
Address 05: Acc/Start Auth.        Labels:. 4F0-910-852.clb
   Part No SW: 4F0 910 852     HW: 4F0 905 852 B
   Component: FBSAUDIC6 ELV   H30 0130  
   Revision: 30040401    Serial number: 10600300088265
   Coding: 0000011
   Shop #: WSC 02323 785 00200
   VCID: 6393A5A0E75EA9A3DA3-8036

   Subsystem 1 - Part No: 4F0 910 131 J
   Component: FBSAUDIC6 EZS   H43 0070

   Subsystem 2 - Part No: 4F0 910 220 A
   Component: FBSAUDIC6 IDG   H36 0040

1 Fault Found:
01049 - Supply Voltage Term 50 
            006 - Short to Plus
             Freeze Frame:
                    Fault Status: 01100110
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 225
                    Mileage: 247533 km
                    Time Indication: 0
                    Date: 2021.09.20
                    Time: 17:39:57


-------------------------------------------------------------------------------
Address 07: Control Head        Labels: 4F0-910-7xx-07-H.clb
   Part No SW: 4F0 910 730 E    HW: 4E0 035 729 
   Component: Interfacebox    H43 1070  
   Revision: 00000000    Serial number: 360KO047510393
   Coding: 0000003
   Shop #: WSC 02327 785 00200
   VCID: 2313E5A0A7DEE9A39A3-8076

   Subsystem 1 - Part No: 4F0 910 609 
   Component: Bedienteil MMIC6H07 0870

   Subsystem 2 - Serial number: 00000000076477

   Subsystem 3 - Serial number: 0105.11.040000000100010296ÿ

   Subsystem 4 - Serial number: 010296ÿ

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC        Labels: 4F0-910-043.clb
   Part No SW: 4F0 910 043     HW: 4F1 820 043 J
   Component: KLIMABETAETIGUNGH11 0110  
   Revision: 00000023    Serial number: 00000000081314
   Coding: 0524326
   Shop #: WSC 02327 785 00200
   VCID: 5BE39D40DF2E9163923-800E

No fault code found.

-------------------------------------------------------------------------------
Address 09: Cent. Elect.        Labels: 4F0-910-279.lbl
   Part No SW: 4F0 910 279     HW: 4F0 907 279 
   Component: ILM Fahrer      H14 0080  
   Revision: 00000000    Serial number: 4F0907279     
   Coding: 0013123
   Shop #: WSC 02335 785 00200
   VCID: 6695BCB4146CDC8B3DD-8032

   Subsystem 1 - Part No: 4F1 910 113   Labels: 1KX-955-119.CLB
   Component: Wischer AudiC6  H05 0150  
   Coding: 00062736
   Shop #: WSC 02335  

   Subsystem 2 - Part No: 4E0 910 557   Labels: 8K0-955-559.CLB
   Component: REGENLICHTSENSORH10 0050  
   Coding: 00141886
   Shop #: WSC 02335  

No fault code found.

-------------------------------------------------------------------------------
Address 0E: Media Player 1        Labels: 4E0-910-111.lbl
   Part No SW: 4E0 910 111 E    HW: 4E0 035 111 A
   Component: CD-Changer      H44 0430  
   Revision: 00000000    Serial number: AUZ5ZBD7100824
   Shop #: WSC 00000 000 00000
   VCID: 1B63DD409FAED163523-804E

No fault code found.

-------------------------------------------------------------------------------
Address 0F: Digital Radio        Labels: None
   VCID: 55F78B78BD0A4713A47-8000

No Faults Found
  or DTCs not supported by controller
  or a communication error occurred

-------------------------------------------------------------------------------
Address 15: Airbags        Labels: 4F0-910-655-8R.clb
   Part No SW: 4F0 910 655 B    HW: 4F0 959 655 A
   Component: 56 AIRBAG AUDI8RH29 0230  
   Revision: 10H29000    Serial number: 00359D080X8-  
   Coding: 0013622
   Shop #: WSC 02327 785 00200
   VCID: 2615FCB4D4EC1C8BFDD-8072

   Subsystem 1 - Part No: 4F0 910 339 
   Component: BF-Gewichtsens. 002 0040

   Subsystem 2 - Serial number: 6332CSME0747167F8

   Subsystem 3 - Serial number: 6342CSME07164C0D5

   Subsystem 4 - Serial number: 6351HSME050E46646

   Subsystem 5 - Serial number: 6361HSME0475042D3

   Subsystem 6 - Serial number: 6371VSME04290826E

   Subsystem 7 - Serial number: 6381VSME04260F0DO

No fault code found.

-------------------------------------------------------------------------------
Address 16: Steering wheel        Labels: 4F0-910-549.lbl
   Part No SW: 4F0 910 549     HW: 4F0 953 549 A
   Component: Lenksäulenmodul H07 0230  
   Revision: 00H07000    Serial number: 90025043020303
   Coding: 0002041
   Shop #: WSC 02323 785 00200
   VCID: 6695BCB4146CDC8B3DD-8032

   Subsystem 1 - Part No: XXXXXXXXXXX 
   Component: Lenkradmodul    H05 0080

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments        Labels: 4F0-910-xxx-17.lbl
   Part No SW: 4F0 910 900 A    HW: 4F0 920 950 M
   Component: KOMBIINSTR. M73 H09 0460  
   Revision: 00300000    Serial number: 4I211H3C4     
   Coding: 0065263
   Shop #: WSC 12345 111 45725
   VCID: 1E65D4548CBCC44BB5D-804A

No fault code found.

-------------------------------------------------------------------------------
Address 19: CAN Gateway        Labels:. 4F0-910-468.clb
   Part No SW: 4F0 910 468 A    HW: 4F0 907 468 B
   Component: Gateway         H09 0030  
   Revision: 09          Serial number: 0800804A200180
   Coding: 6CFE73CC1B1904
   Shop #: WSC 12345 111 45725
   VCID: 270BF1B0D3E60583C6B-8072

No fault code found.

-------------------------------------------------------------------------------
Address 36: Seat Mem. Drvr        Labels: None
   Part No SW: 4F0 910 760     HW: 4F0 959 760 
   Component: Sitzmemory FS   H04 0050  
   Revision: 00000000    Serial number: 00000000896400
   Coding: 0082946
   Shop #: WSC 02327 785 00200
   VCID: 619FAFA8FD42BBB3C8F-8034

No fault code found.

-------------------------------------------------------------------------------
Address 42: Door Elect, Driver        Labels: 4F0-910-793-42.lbl
   Part No SW: 4F0 910 793 B    HW: 4F0 959 793 B
   Component: TSG FA          H10 0020  
   Revision: 00000000    Serial number: s1
   Coding: 0035563
   Shop #: WSC 02327 785 00200
   VCID: 290FF788C5F233F3D0F-807C

No fault code found.

-------------------------------------------------------------------------------
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: 01001538210000
   Coding: 0423997
   Shop #: WSC 02335 785 00200
   VCID: 2C010E9CCA0026DB2B9-8078

   Subsystem 1 - Component:   Sounder No Answer     

2 Faults Found:
01134 - Alarm Horn (H12) 
            004 - No Signal/Communication - Intermittent
             Freeze Frame:
                    Fault Status: 00100100
                    Fault Priority: 3
                    Fault Frequency: 10
                    Reset counter: 9
                    Mileage: 247521 km
                    Time Indication: 0
                    Date: 2021.09.19
                    Time: 14:10:36

01134 - Alarm Horn (H12) 
            014 - Defective
             Freeze Frame:
                    Fault Status: 01101110
                    Fault Priority: 3
                    Fault Frequency: 21
                    Reset counter: 225
                    Mileage: 247519 km
                    Time Indication: 0
                    Date: 2021.09.15
                    Time: 10:46:25


-------------------------------------------------------------------------------
Address 47: Sound System        Labels: 4F0-910-223-BO.lbl
   Part No SW: 4F5 910 223 C    HW: 4F5 035 223 D
   Component: DSP-High C6     H14 0240  
   Revision: PROD_01     Serial number: 00000000012607
   Coding: 0000016
   Shop #: WSC 02327 785 00200
   VCID: 2313E5A0A7DEE9A39A3-8076

No fault code found.

-------------------------------------------------------------------------------
Address 4F: Centr. Electr. II        Labels: 4F0-910-280.lbl
   Part No SW: 4F0 910 280     HW: 4F0 907 280 A
   Component: ILM Beifahrer   H09 0050  
   Revision:             Serial number: 00000000045758
   Coding: 0001114
   Shop #: WSC 02323 785 00200
   VCID: 5EE59454CC3C844BF5D-800A

No fault code found.

-------------------------------------------------------------------------------
Address 52: Door Elect, Pass.        Labels: 4F0-910-793-52.lbl
   Part No SW: 4F0 910 793 B    HW: 4F0 959 792 B
   Component: TSG BF          H10 0020  
   Revision: 00000000    Serial number: C1
   Coding: 0035563
   Shop #: WSC 02327 785 00200
   VCID: 290FF788C5F233F3D0F-807C

No fault code found.

-------------------------------------------------------------------------------
Address 53: Parking Brake        Labels: 4F0-910-801.clb
   Part No SW: 4F0 910 801     HW: 4F0 907 801 
   Component: EPB  C63C0030   H03 0030  
   Revision: C63C0030    
   Coding: 0005022
   Shop #: WSC 02334 785 00200
   VCID: 5DE79358C13A9F53EC7-8008

No fault code found.

-------------------------------------------------------------------------------
Address 55: Headlight Range        Labels: 4F0-910-357.lbl
   Part No SW: 4F0 910 357 C    HW: 4F0 907 357 C
   Component: AFS 1           H01 0010  
   Revision: 00000001    Serial number:               
   Coding: 0000016
   Shop #: WSC 02327 785 00200
   VCID: 2615FCB4D4EC1C8BFDD-8072

   Subsystem 1 - Part No: 4F0 941 329 A
   Component: AFS-Modul links H05 0010

   Subsystem 2 - Part No: 4F0 941 329 A
   Component: AFS-Modul rechtsH05 0010

No fault code found.

-------------------------------------------------------------------------------
Address 56: Radio        Labels: 4E0-910-541.lbl
   Part No SW: 4E0 910 541 F    HW: 4F0 035 541 B
   Component: TUNER EU/US/RDW H42 0480  
   Revision: 00000000    Serial number: 394KN047500440
   Coding: 0000002
   Shop #: WSC 02327 785 00200
   VCID: 2313E5A0A7DEE9A39A3-8076

No fault code found.

-------------------------------------------------------------------------------
Address 61: Battery Regul.        Labels: 4F0-910-181.lbl
   Part No SW: 4F0 910 181 E    HW: 4F0 915 181 A
   Component: ENERGIEMANAGER  H11 0400  
   Revision: 00000000    Serial number: 00000000079009
   Shop #: WSC 02665 444 54596
   VCID: 2313E5A0A7DEE9A39A3-8076

   Subsystem 1 - Part No: 4F0 915 105 C
   Component: von VA0  4411050223       
   Coding: 344630393135313035432056413034343131303530323233
   Shop #: WSC 02335 823 59926

1 Fault Found:
00003 - Control Module 
            014 - Defective
             Freeze Frame:
                    Fault Status: 01101110
                    Fault Priority: 3
                    Fault Frequency: 255
                    Reset counter: 255
                    Mileage: 246685 km
                    Time Indication: 0
                    Date: 2021.06.30
                    Time: 14:13:36


-------------------------------------------------------------------------------
Address 62: Door, Rear Left        Labels: 4F0-910-795.lbl
   Part No SW: 4F0 910 795     HW: 4F0 959 795 
   Component: TSG HL          H09 0010  
   Coding: 0035370
   Shop #: WSC 02327 785 00200
   VCID: 698FB7880572F3F310F-803C

No fault code found.

-------------------------------------------------------------------------------
Address 72: Door, Rear Right        Labels: 4F0-910-795.lbl
   Part No SW: 4F0 910 795     HW: 4F0 959 794 
   Component: TSG HR          H09 0010  
   Coding: 0035370
   Shop #: WSC 02327 785 00200
   VCID: 698FB7880572F3F310F-803C

No fault code found.

-------------------------------------------------------------------------------
Address 77: Telephone        Labels: 4E0-910-336.lbl
   Part No SW: 4F0 910 336 A    HW: 4E0 862 335 
   Component: Handyvorb2      H10 0120  
   Revision: 00000000    Serial number: 00000007507343
   Coding: 0010900
   Shop #: WSC 02335 785 00200
   VCID: 211FEFA8BDC2FBB388F-8074

No fault code found.

End----------(Elapsed Time: 02:51, VBatt start/end: 12.2V/12.2V)-----------

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


Address 01: DTCs cleared
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 01: DTCs cleared
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 01: DTCs cleared
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 01: DTCs cleared
 
   #4  

precursor

Verified VCDS User
Verified
Joined
Jul 7, 2021
Messages
9
Reaction score
8
Location
Midwest, USA
VCDS Serial number
C?ID=433554
I've been thinking this over some more. Since clearing the code briefly creates good idle, I guess some of my purely mechanical theories can't be the problem. Like: it's probably not engine mounts (which do have electronic connectors on this car, but I assume they're basically just sensors, not some sort of active adjustment). Clogs in the fuel system are probably out as well, as vcds can't control that.

If it's a faulty G300 camshaft position sensor (or faulty wiring to that sensor), maybe it makes sense that clearing the code smooths out the idle. Maybe clearing the code removes all the bad data it's been passing to the ECM, and it takes a few seconds for the ECM to process the new flow of bad data, post-code-clearing. But eventually it does get that new, bad data, so the idle turns rough again.

Whaddaya think? Plausible?

(And if so, is there any reasonable way to test the sensor itself, vs. the wiring? Or would most of you just change the sensor and hope that's it?))
 
   #5  

stefdds

Verified VCDS User
Verified
Joined
Apr 13, 2015
Messages
740
Reaction score
552
Location
USA
VCDS Serial number
C?ID=174556
Thank you for that Auto-scan , as recommended by @PetrolDave , Just a observation, but I thought it odd that the Immobilizer address-25 doesn't show up in the scan (?) , others I'm sure will comment on that.

I thought this was a good YT video for > Testing that Cam P.S. < ; Also, how much extra oil did you drain out? You may have a leaking injector or one that is not atomizing properly ; See Ross-Tech video for > testing fuel rail pressure. <
 
   #6  

precursor

Verified VCDS User
Verified
Joined
Jul 7, 2021
Messages
9
Reaction score
8
Location
Midwest, USA
VCDS Serial number
C?ID=433554
I'd say it had close to a quart too much oil.

I'll look into the youtube videos. Thanks for the leads.
 
   #7  

stefdds

Verified VCDS User
Verified
Joined
Apr 13, 2015
Messages
740
Reaction score
552
Location
USA
VCDS Serial number
C?ID=174556
Also, a couple of additional thoughts: I would plan on changing your oil, as unless you know otherwise (like you just did a oil change and know you overfilled it) it is probably not pure oil any longer! It most likely has a bunch of fuel in it. (leaking , clogged, carbon build up injector(s) or leaking High Pressure fuel pump(s). Why did you happen to check the oil ? Have you had a history of this over level condition (misfires etc. ) in the past ?
 
   #8  

precursor

Verified VCDS User
Verified
Joined
Jul 7, 2021
Messages
9
Reaction score
8
Location
Midwest, USA
VCDS Serial number
C?ID=433554
Was looking at oil because oil was changed about a month ago, and that very roughly correlates with when this started. I will change it again, soon.

However, oil level can't be the main issue here... it just wouldn't explain the code situation. The main issue seems to be very much related to the camshaft position sensor. The fact that I can get a 100% pure idle for a few seconds every time I clear the camshaft code... (I just tested it again some more. Still works every single time the code gets cleared).

I tested the wiring to the camshaft sensor, and the sensor itself. It's a little different from the video linked, because the Audi has 5v coming from both the battery and the sensor/ECM (I verified that's how it's supposed to be). Hooking up the sensor to the multimeter with the car switched on, I could indeed get the voltage on the sensor wire to drop from 5v to 0v when bringing a metal object near the sensor. However, while this may be a result of shaky connections on my test setup, I didn't feel like the voltage dropped as easily and automatically as shown in the video. I suppose it's possible the sensor is just flaky, and "sorta" works. Which would possibly explain that implausible signal code.

I have an automotive reference guide that mentions using oscilloscopes to make sure the camshaft sensor is producing a certain waveform. I'd imagine the "put a metal object next to the sensor and see if the sensor wire voltage drops" trick is a fairly crude test, and could miss some things.

Man, this is killing me. The fact that I can Make Things Better for a few seconds every time I clear that code... I feel like that must be a very obvious tell to someone with experience working on these things. Urgh.
 
   #9  

precursor

Verified VCDS User
Verified
Joined
Jul 7, 2021
Messages
9
Reaction score
8
Location
Midwest, USA
VCDS Serial number
C?ID=433554
I shouldn't say, by the way, that oil level "can't" be the main issue. I have way too little experience to speak in absolutes. ;)

I appreciate your input as I muddle through this.

Next step is probably to grab a new camshaft position sensor. I hate throwing $ at speculative parts, but a defective sensor seems like a reasonable possibility, and I don't think they cost too much.
 
   #10  

precursor

Verified VCDS User
Verified
Joined
Jul 7, 2021
Messages
9
Reaction score
8
Location
Midwest, USA
VCDS Serial number
C?ID=433554
I figured out the issue! Thanks for the help. I'd meant to just leave it alone and have a pro take a look, after wasting way too much of my time on it... but I couldn't get it out of my mind, and kept looking for answers online.

Lots and lots of googling on this:

P0366-006 Implausible Signal

finally pointed me toward the variable valve timing solenoids. I pulled the two solenoids closest to the G300 sensor (the one that was implicated by the fault codes), and jolted them repeatedly with a battery from my power tool collection (this "shock therapy" was mentioned in some places as a way to get sticky valve timing solenoids back to life).

Honestly, the shock therapy was mostly just to test that the solenoids opened and closed properly when supplied with voltage. (If the higher voltage somehow helped to make them less sticky, then that was just an added bonus.)

I believe the real fix was that I retrieved a metal shaving from inside the solenoid closest to the camshaft sensor. It was small, but sharp and inflexible, and was lodged between the inner core and the outer, sliding part of the solenoid. I believe it was interfering with the open/close sliding action. My understanding is that this would have prevented the engine from properly acting upon the data it received from the camshaft position sensor. The result would be a slight loss of sync between camshaft and crankshaft.

In retrospect: every time I cleared the fault code for the camshaft position sensor, I believe what was happening was, I got a couple seconds of grace period while the sensor data reset. During this time, the ECM wasn't trying to adjust anything about the timing chain, via the solenoids. (In effect, during those couple of seconds, I got a "vanilla" idle based on preset values, with no ECM interference.) But then the sensor data started flowing again, and the ECM started trying to use the solenoids to make adjustments, but one of the solenoids wasn't doing what it was supposed to do. The result was a loss of sync.

Also in retrospect, while the oil overfill might have been blameless, it also might have pressurized the engine or whipped the oil into a froth, thus causing whatever (hopefully minor) damage led to that little metal flake stuck in the solenoid. Or, maybe not actually doing damage, but whipping up some little bits of debris that got in the engine on previous occasions, and giving them the chance to get stuck somewhere harmful.

I hope this will help someone in the future, as they try to run down possible reasons for Camshaft Position Sensor - Implausible Signal codes.
 
   #11  

stefdds

Verified VCDS User
Verified
Joined
Apr 13, 2015
Messages
740
Reaction score
552
Location
USA
VCDS Serial number
C?ID=174556
Thank you for the follow up and the additional information; I'm certain the next member who comes along with this issue will find it very helpful. If you can, a few pictures of the VVT solenoids and where you found the foreign debris may also help. Congratulations and don't you think that was much more rewarding that taking it to a dealer? ;)
 
   #12  

precursor

Verified VCDS User
Verified
Joined
Jul 7, 2021
Messages
9
Reaction score
8
Location
Midwest, USA
VCDS Serial number
C?ID=433554
I didn't take pics (will try to remember in the future) but I will look for one I can grab online, and mark it up to show the spot.

I very much like fixing things myself, but I don't have much experience and I was having a really hard time pinning this down. Since the possibilities included major stuff like full timing chain replacement (which would effectively total the car, given its value) and engine mounts (which I haven't done, and would probably try, but which I suspect would be a lot of grief on this model), I broke down and was planning to get a pro diagnosis. There are a number of less-concerning things for me to fix on the car, but I wanted to avoid the rabbit hole of pouring lots of time and sweat into a car that I might have to get rid of.

Just for example, I don't have a great idea of exactly how much play the engine should have when it's idling or moving. And it's hard to get a great feel for something like that from youtube videos. So, while a pro might be able to look at it and say: yeah, the engine is flopping around, it's the mounts... I didn't know how to reach any certainty about that. And I hate replacing parts that don't need to be replaced.

Fortunately I have a little indie shop that specializes in VW Audi, within walking distance of my house. And they're great. The only downside is it's hard to book with them, as they're always busy. But in this case that was a positive, as it gave me a couple of weeks to try to solve things in the meantime.
 
   #13  

precursor

Verified VCDS User
Verified
Joined
Jul 7, 2021
Messages
9
Reaction score
8
Location
Midwest, USA
VCDS Serial number
C?ID=433554
The code I kept getting was:

Camshaft Position Sensor B Bank 1 (G300)
P0366-006 Implausible Signal

This illustration shows the G300 camshaft sensor (labeled 5), which turned out to be fine... and also the variable timing valve/solenoid (labeled 1), which is officially called N318 Camshaft Adjustment Valve 1 (Exhaust). That's what turned out to be the actual problem. Note that this view is of the passenger side of the engine (North America). You need to remove the air intake hose and the top of the air box in order to get this view.

g300.jpg%22 alt=%22g300%22 border=%220%22>


This is what the variable timing valve looks like when you pull it. It consists of an outer metal sleeve with holes drilled in it, and an inner core which also has holes drilled in it. The core slides up and down when voltage is applied. Depending on whether the core is up or down, oil can either flow through the holes (when holes in core and sleeve line up) or will be blocked (when the holes are not aligned).

Sending voltage through the electrical connector should cause a loud, definite click as the core snaps into its new position. When I applied voltage to this one, I got a somewhat unsatisfying click. Inspecting it, I found a mostly-flat chip of metal in one of the holes, sitting on the inner core. It was held in place by some oil. It partially obstructed the sliding action. I used a small tool to remove it, and cleaned the rest of the part with rubbing alcohol. Now when I applied voltage, it made a much more definitive click. I replaced it, and my idle was good again. I no longer got the P0366 code.

solenoid.jpg
 
   #14  

stefdds

Verified VCDS User
Verified
Joined
Apr 13, 2015
Messages
740
Reaction score
552
Location
USA
VCDS Serial number
C?ID=174556
Beautiful!
 
Top