Car intermittently not starting, cranks fully (S4 B6)

[Gurpreet Singh]

Hi,

I've run into a problem since yesterday intermittently whereby my car will crank and crank but not start. Randomly it will start, and randomly it won't. It's happened about 3/10 starts since yesterday, no new codes are showing (except G28 speed sensor), I was told by a friend it may be electrical and looking online it looks like maybe a relay but I'm hoping it's not a fuel or pressure issue.

I'm trying to sell my car and have someone viewing this weekend so don't want to sink too much into the car but I don't want to sell it to someone if it has a big problem. Any advice is appreciated - I'm aware of the airbag MIL and rear left light along with the alarm codes:

Friday,23,June,2017,21:17:55:11979
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 7 x64
VCDS Version: 17.1.3.0 (x64)
Data version: 20170320 DS267.7
www.Ross-Tech.com


VIN: WAUZZZ8E64A071458   License Plate: 
Mileage: 157660km-97965mi   Repair Order: 



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


Chassis Type: 8E (8E - Audi A4/S4/RS4 B6/B7 (2001 > 2008))
Scan: 01 02 03 08 09 0F 11 15 16 17 18 25 36 37 45 46 55 56 57 65
          67 69 75 76 77

VIN: WAUZZZ8E64A071458   Mileage: 157660km-97965miles
-------------------------------------------------------------------------------
Address 01: Engine        Labels: 079-910-560-BBK.lbl
   Part No SW: 8E0 910 560 B    HW: 8E0 907 560 
   Component: 4.2L V8/5V      G   0020  
   Coding: 0011771
   Shop #: WSC 33278 133 00032
   VCID: 2443AFDBE4F53461AD-515A

2 Faults Found:
17979 - Left Engine Mount Solenoid Valve (N144) 
            P1571 - 001 - Short to Plus
16706 - Engine Speed Sensor (G28) 
            P0322 - 004 - No Signal - Intermittent
Readiness: 0000 0000

-------------------------------------------------------------------------------
Address 02: Auto Trans        Labels: 09L-927-760.lbl
   Part No SW: 8E0 910 156     HW: 09L 927 156 
   Component: AG6 09L 4.2L5V RdW  0020  
   Revision: 00000001    Serial number:        0001719
   Coding: 0001001
   Shop #: WSC 63351 000 00000
   VCID: 63C1ECC7A17B735994-515A

No fault code found.

-------------------------------------------------------------------------------
Address 03: ABS Brakes        Labels: 8E0-614-517.lbl
   Part No: 8E0 614 517 Q
   Component: ABS/ESP allrad      3033  
   Coding: 04597
   Shop #: WSC 06435  
   VCID: 366765931269B6F103-513C

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC        Labels: 8E0-820-043.lbl
   Part No: 8E0 820 043 AA
   Component:   A4 Klimaautomat   1219  
   Coding: 00000
   Shop #: WSC 63351  
   VCID: 60CBE3CBE06D684189-515A

No fault code found.

-------------------------------------------------------------------------------
Address 09: Cent. Elect.        Labels: 8E0-907-279-8E2.lbl
   Part No: 8E0 907 279 F
   Component: int. Lastmodul  RDW 0517  
   Coding: 00011
   Shop #: WSC 63351  
   VCID: 3565629F0F6FBDE90A-4B32

2 Faults Found:
00984 - Left Tail Light (M4) 
            57-00 - Electric Circuit Failure
01312 - Powertrain Data Bus 
            79-00 - Please Check Fault Codes

-------------------------------------------------------------------------------
Address 15: Airbags        Labels: 8E0-959-655-84.lbl
   Part No: 8E0 959 655 B
   Component: Airbag 8.4EP        3002  
   Coding: 0010602
   Shop #: WSC 63351 000 00000
   VCID: 366765934269B6F103-515A

1 Fault Found:
01217 - Side Airbag Igniter; Driver Side (N199) 
            001 - Upper Limit Exceeded - MIL ON

-------------------------------------------------------------------------------
Address 16: Steering wheel        Labels: 8E0-953-549.lbl
   Part No: 8E0 953 549 N
   Component: Lenksáulenmodul     0611  
   Coding: 01141
   Shop #: WSC 63351  
   VCID: 3E777DB33A597EB1DB-4B32

2 Faults Found:
00576 - Terminal 15 
            57-10 - Electric Circuit Failure - Intermittent
00883 - Ignition Switch (D) Terminal S 
            57-10 - Electric Circuit Failure - Intermittent

-------------------------------------------------------------------------------
Address 17: Instruments        Labels: 8E0-920-9xx-8E2.lbl
   Part No: 8E0 920 980 L
   Component: KOMBI+WEGFAHRS. RB4 D36  
   Coding: 01400
   Shop #: WSC 00001  
   VCID: 3565629F0F6FBDE90A-515A

   Subsystem 1 - Part No: 71458
   Component: AUZ6Z0C0081035  
   71458     AUZ6Z0C0081035

No fault code found.

-------------------------------------------------------------------------------
Address 45: Inter. Monitor        Labels: 8E0-951-177.lbl
   Part No: 8E0 951 177 
   Component: Innenraumueberw.   0604  
   Coding: 00001
   Shop #: WSC 00000  
   VCID: 6BD184E719AB3B192C-513C

No fault code found.

-------------------------------------------------------------------------------
Address 46: Central Conv.        Labels: 8E0-959-433-MAX.clb
   Part No: 8E0 959 433 BC
   Component: Komfortgerát T3B    1311  
   Coding: 06891
   Shop #: WSC 63351  
   VCID: 73E19C87419BE3D9E4-4B18

   Subsystem 1 - Part No: 8E2959802B
   Component: Tõrsteuer.FS BRM 0003  

   Subsystem 2 - Part No: 8E2959801B
   Component: Tõrsteuer.BF BRM 0003  

   Subsystem 3 - Part No: 8E0959801A
   Component: Tõrsteuer.HL BRM 0003  

   Subsystem 4 - Part No: 8E0959802A
   Component: Tõrsteuer.HR BRM 0003  

3 Faults Found:
01134 - Alarm Horn (H12) 
            49-00 - No Communications
01366 - Opened Due to Crash Signal 
            35-00 -  - 
01561 - Rear left door 
            61-10 - Won't De-Safe - Intermittent

-------------------------------------------------------------------------------
Address 55: Headlight Range        Labels: 4Z7-907-357.lbl
   Part No: 4Z7 907 357 
   Component: dynamische LWR       D09  
   Coding: 00060
   Shop #: WSC 63351  
   VCID: 0403CF5B1435D461CD-4B4A

No fault code found.

-------------------------------------------------------------------------------
Address 56: Radio        Labels: 8E0-035-1xx-56.lbl
   Part No: 8E0 035 186 J
   Component: concert II  GRO    0008  
   Coding: 01202
   Shop #: WSC 63351  
   VCID: 2E574DF3EA398E314B-4B18

No fault code found.

-------------------------------------------------------------------------------
Address 76: Park Assist        Labels: 8Z0-919-283.lbl
   Part No: 8Z0 919 283 A
   Component: Parkingsyst. A4 RDW D09  
   Coding: 01104
   Shop #: WSC 06435  
   VCID: 43810C4751BB1359B4-5178

2 Faults Found:
00625 - Vehicle Speed Signal 
            27-00 - Implausible Signal
01550 - Signal for Reverse Gear 
            27-10 - Implausible Signal - Intermittent

End-------------------------(Elapsed Time: 05:28)--------------------------

 

[joinerman]

Probably the fuel relay that lives under the ECU, there only a few pence so worth trying, it's universal to many makes of car so if you have a scrappy near by you could get one from nearly any make of car.

Many of those codes are probably historic.

 

[THQuattro]

As above but could be the crank sensor.

 

[Gurpreet Singh]

Thanks guys, is the FP relay the 9 pin labelled "167"?

And is the crank sensor the one mentioned below?
http://www.pelicanparts.com/techart...Crankshaft_Positioning_Sensor_Replacement.htm

 

[THQuattro]

I cannot tell you where the crank sensor is, sorry.

 

[pauldazzle]

Crank or cam sensor failure can cause random start problems, often worse with a hot engine.

 

[s3tby]

In my view the car has reported the problem to you. It's the G28 sensor aka engine speed sensor aka crankshaft position sensor. Very common on this age of A4. My car did the same thing exactly yesterday! Slow to finally start then displayed an EPC light on the dash and sat idling high even though warm. Turned engine on/off and it went away though of course I know it'll come back so....

Scanned on VCDS (my car is error free but for this new fault logged yesterday):

16706 - Engine Speed Sensor (G28): No Signal P0322 - 004 - No Signal/Communication - Intermittent

....£10 on eBay and an easy 30 minute fix as you've seen from your own link (though you do need to get under the car). The car not starting of course is a big viewing no-no,though that fault in itself, now that I understand it, wouldn't stop me buying the car.

Good luck.

 

[Gurpreet Singh]

Just thought I'd update this thread in case anyone has the same problem

Replaced the fuel pump relay, no change
Replaced the crankshaft sensor, everything seems to be good now! Done about 30 starts since I replaced the sensor and none have failed or taken longer than usual.

Thanks guys!

 

[QuattroCalum]

Just thought I'd update this thread in case anyone has the same problem

Replaced the fuel pump relay, no change
Replaced the crankshaft sensor, everything seems to be good now! Done about 30 starts since I replaced the sensor and none have failed or taken longer than usual.

Thanks guys!

Good news, I have had that problem before on my previous car and reading it again makes me think I should just change this sensor now as a pre emptive strike, it's a cheap part and it is destined to fail soon, good luck with sale


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