2.0TFSI fault code 01314

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km666

Original Poster:

1,757 posts

182 months

Saturday 29th September 2018
quotequote all
TLDR at bottom.

As per the title, I’ve been diagnosing an odd fault code I found on a cheapo 2.0 TFSI Leon I bought. Information about this code isn’t great, the Ross Tech Wiki gives the vaguest description I’ve ever seen for any fault code, basically suggesting the ECU or ABS module are fried. I got some good advice off somebody from Briskoda and hopefully this might help anybody else struggling with this weird fault code.

Background: Initially the advert made it appear to be a perfectly working vehicle. When collected the previous owner claimed they had stalled the car on their way to meet me causing the engine light and TC light to illuminate and put the car into a soft limp mode, and would stall at idle without a bit of throttle when started, but they said this often happens and the lights will go out. Well they didn’t, after disconnecting the battery the engine light went out, the TC light remained and the EPC light came on instead.

I scanned it with a vagcom reader and the only fault code stored was 01314 under the ABS section. It wouldn’t allow me to clear this code at this time.

Based on the Ross Tech Wiki and the advice I got I started by checking the ECU for water damage, it looks good but I decided to whip it out and clean the connections. I then checked the loom to the ABS module and that was good. So the ECU and ABS module being fried started looking unlikely.

I then recalled that the coils do weird things when they start giving up and don’t tend to log specific faults. So all 4 coils and spark plugs got replaced, here I discovered that the engine cover had allowed water to pool around one coil, apparently just bad design by VAG with the engine cover.

I changed the filters and fluids and started it up again, it then allowed me to clear the code and all lights went out.

However today on the dual carriageway, 6th gear and I applied the throttle slightly, it felt like it skipped a beat, not quite a misfire, similar but felt more 'electronic' than mechanical. The EPC and TC lights came on and again it went into soft limp mode. I parked up in Tesco, came back after 5 minutes and again stalled at idle after starting but came back to life. 30 seconds later the EPC light went out and the car went out of limp mode but the TC light remained on.

So I scanned it again and 01314 was back under ABS. However this time it let me clear the code.

Thinking back to what I’d removed I realised that I’d unplugged the MAF to take the engine cover off. Having read that the MAF will do all sorts of bizarre things and that VAG cars rarely seem to log a MAF fault as a MAF fault code I decided to unplug it with the car running and rescan.

01314 was back and again it appeared under ABS. Cleared it, started again, no code. I repeated this over 5 cycles with and without the MAF plugged in and every time without the MAF it would log this fault code under ABS. Given that I’ve now found I can manipulate the car into giving me this code by messing with the MAF it would seem that is the root cause.

Reading around it would seem a bad MAF can overload the ECU with duff data which in turn confuses it. However there seems to be a lot of duff data online with an equal number of people claiming a bad MAF will never cause any ABS or TC lights/fault codes as those who say that as I’ve found they actually do. Even better is Audi Sport where somebody starts describing similar circumstances, somebody else starts diagnoses it and a moderator shuts it down because of the brand of VCDS cable used.

For TLDR: Fault code 01314 being logged under ABS could be a bad MAF.