SOLVED: Fabia cranks but won't start - sometimes!

[Al115]

Hello all,

Our Fabia 1.4 16v will sometimes crank but not start. With patience / persistence, it will eventually start. Battery is fine, problem occurs with either key. Any clues as to where I should start looking?

I did read the fault codes and there was nothing obvious (the S-Contact fuse had blown - I replaced it - then all the fault codes cleared down).

I will wait for the problem to recur and then read the codes again, but in the meantime - any advice? Is there a known fault that would be a good place to start?

Cheers for any help.

[Tech1e]

Fuel pump relay maybe?

[Al115]

Good thinking, I will check that tomorrow. Almost certainly have a spare in the garage (from Previous, now Dead Fabia). Thank you!

[Al115]

Fuel pump relay seems fine. Shame eh, would have been an easy fix!

[Tech1e]

How did you test?

[Al115]

Pulled the relay, put voltage across the coil 40-odd times, heard it clicking away. That might not be the best way to check it, but it was all I could think of... I was assuming it was a binary "it works or it doesn't" thing!

Is there a better way? Happy to hear any advice!

Thanks for your help.

[Tech1e]

That will only check the primary windings not the secondary side though won't it?

[Al115]

Should have put a meter across the hot side, that would have been an idea

TBH I was pretty short on time (I'd assumed that the relays would be somewhere accessible) - I will have another look at it when I'm back next...

[Tech1e]

What were the faults stored before?

Normally if the fuel pump relay gives issue you will get injector, fuel tank breather and various sensor faults as they are supplied via relay.

Ideally what you want to do is get the fault, bridge out the relay socket and see if it starts.

[Al115]

I will have a look at the codes that were stored once I am home again (I read them with my laptop but they didn't seem to point to anything especially meaningful!)

Thanks for the guidance.

[Al115]

So here's what we have (just posting the faults) - these are recently stored, since I cleared the car down last time:

VCDS-Lite Version: Release 1.1
Thursday, 23 June 2011, 19:41:10:1559

Chassis Type: 6Y - Skoda Fabia I
Scan: 01,02,03,08,09,15,17,19,25,37,44,46,55,56,76

<snip>

-------------------------------------------------------------------------------
Address 09: Cent. Elect.       Labels: 6Qx-937-049-B.LBL
  Controller: 6Q1 937 049 
  Component: BORDNETZ-SG.        1S30
  Coding: 09362
  Shop #: WSC 13765
  VCID: F883EDF4CBDD
1 Fault Found:
01314 -  Engine Control Module
           49-10 -  No Communications - Intermittent

<snip>

-------------------------------------------------------------------------------
Address 17: Instruments       Labels: Redir Fail!
  Controller: 6Y2 919 880 B
  Component: KOMBIINSTRUMENT VDO V06
  Coding: 16442
  Shop #: WSC 13765
  VCID: 5AC7177CD511
  TMBND46Y2Y3019397     SKZ7Z0X0407698
1 Fault Found:
01314 -  Engine Control Module
           49-10 -  No Communications - Intermittent

<snip>

-------------------------------------------------------------------------------
Address 19: CAN Gateway       Labels: 6N0-909-901-19.LBL
  Controller: 6N0 909 901 
  Component: Gateway K<->CAN    1S30
  Coding: 00014
  Shop #: WSC 13765
  VCID: F093D5D4A3AD
1 Fault Found:
01314 -  Engine Control Module
           49-10 -  No Communications - Intermittent

-------------------------------------------------------------------------------
Address 25: Immobilizer       Labels: None
  Controller: Bit teA dre ss
  Component: e 17 eingeben          
  VCID: 5AC7177CD511
No Faults Found
 or DTCs not supported by controller
 or a communication error ocurred

-------------------------------------------------------------------------------
Address 44: Steering Assist       Labels: 6Q0-423-156.LBL
  Controller: 6Q0 423 156 E
  Component: Lenkhilfe           0001
  Coding: 00110
  Shop #: WSC 00000
  VCID: 311590D0E827
1 Fault Found:
01314 -  Engine Control Module
           49-10 -  No Communications - Intermittent

I checked on Ross-Tech for 01314 and:

01314 - Engine Control Module: No Communications 

Possible Causes 
CAN-Databus Wiring/Connectors from/to Engine Control Module faulty 
Fault(s) stored in Engine Control Module
Engine Control Module recently flashed or re-mapped

Possible Solutions 
Check CAN-Databus Wiring/Connectors from/to Engine Control Module 
Check Measuring Value Blocks (MVB) Usually Measuring Value Blocks (MVB) 125+ show the current Communication Status

Checking the CAN-bus wiring doesn't like a picnic... does anyone have any suggestions on where to start with this, please? All help appreciated.

[Al115]

Waiting for it to have another "Non-starting" episode and then I will swap a replacement fuel relay in... the under-dash panel is removed in preparation

It would be great if that solved it.

[fabdavrav]

Maybe the voltage is dropping out?? Check the battery is at least a 60ah and up to charge, then check all the earth conections and the fuses on the top of the battery. Basically using a mulitmeter do short, live, earth, conitunity checks....then disconnect the battery and disconnect the ecu......then do checks on the live & earth wires and the ca

nbus wires on the plugs.

Also it could be the two wire connector on the cable from the alterntor with the connector by the rad drain point (infront of gearbox) as the wiring is a bit tight and the cables break!

Edited 1 July, 2011 by fabdavrav

[Al115]

Thanks - it's wiring time I think - the battery seems fine and gets charged every night while the car is off the road (and I am messing with it!)

[Al115]

FYI I am still chasing this fault down - now in the "Ask a Tech" section since joining Freedom. Thanks again guys for the help so far.

[Al115]

Solution found I'll post it in the "Ask a Tech" section:

http://briskoda.net/forums/topic/206480-fabia-occasional-non-starter/

[lalwong]

I have the same problems. Need help 

Did you find the solution and what it was 

[TMB]

2 hours ago, lalwong said:

I have the same problems. Need help 

Did you find the solution and what it was 

 

Umm, it says they found a solution in the post above yours. There is link to click on.

[lalwong]

I cannot open the link

[TMB]

1 hour ago, lalwong said:

I cannot open the link

 

OK, well here's a copy and paste of the solution...

 

Quote

Found the fault, after many hours spent searching. Thought I would post up here to complete the story.

Short version: it was one of the CONNECTORS on the back of the fuse panel (seen here after I'd identified it and pushed it all the way back through):

http://www.naiad.org.uk/pictures/fabia_fusebox.jpg

Long version: the car has been sitting up for the past couple of months, being moved up and down the driveway every week or so to keep the brakes clear and the tyres un-flatted. I've been trying to reproduce the non-starting fault but without success... it has persistently started each time, to the point where I was starting to wonder if it was "fixed" through one of the things I had swapped out. Today I replaced the window regulator on the driver's side, and then tried to start it - the fuel pump wouldn't prime, as per the regular symptom. So I knew I was onto something.

I found that by hitting the fusebox repeatedly, I could get the fuel pump circuit to engage, or disengage... intermittent fuse I thought. Once I had narrowed down the bit of the fusebox I had to hit, I checked all the fuses - they were fine - and then the connections - one of which was pushed back a little bit too far inside the plastic fuse holder for the fuse to make permanent contact. An easy fix after all that!

THANKS to everyone who helped me through the diagnosis. Happy that the car is now sorted out!

 

[Breezy_Pete]

Fuses 17 and 56 look to be ones to focus attention on, permanent and ignition switched 12V supplies to engine ECU on the 1.4/16v.

Unfortunately the OP's photo isn't working and he/she hasn't logged in for more than 9 years so I doubt that a mention will work... @Al115, how's it going?

Edited 1 December, 2020 by Wino

[lalwong]

I try that tomorrow and let you know know guys. Thanks 

[Breezy_Pete]

Which engine does your car have @lalwong? I've looked at all your posts without discovering that.

[lalwong]

Azq 1.2 47kv fabia classic 2004 

[Breezy_Pete]

In that case look at fuses and fuse connections for fuse numbers 14 and 52 instead.

Are you getting the same faults as shown in the scan here? Communication trouble between engine ECU and other modules?

Edited 1 December, 2020 by Wino