Advice needed: Engine management light/car goes into limp mode - need help identifying fault code

owenjt

Registered User
Joined
Oct 17, 2010
Messages
134
Reaction score
5
Points
18
I have a 2010 Audi A3 2.0 TDI. Was driving home to London from Wales on Saturday and about 30mins from home an engine management light came on (the coil) and the car went into limp mode. I managed to get home after stopping a couple of times and switching the engine off (which removed the light) and continuing my journey.

I've now used the Carista app to find the fault and it comes up with the following:

Engine:
04984
04987


Can anyone help identify what these mean? I've searched and seen mentions of the glow plugs. The car can take a few seconds to start which is an issue that's been there for a while - I did have a garage do a diagnostic check in 2017 for a different issue and they said there was also an issue with glow plug no.2 and it needed replacing (but said the car could still run ok).

Could it be that another glow plug has failed? Would this cause the light to come on whilst driving? Any help/advice appreciated.
 

04984 - Cylinder 1 Glow Plug Circuit (Q10)
04986 - Cylinder 3 Glow Plug Circuit (Q12

So I'd assume 04987 is cylinder 4.
 
  • Like
Reactions: owenjt
I can’t see why a glow plug issue would stop the car into a journey. I thought they were only used for starting in cold weather?
 
  • Like
Reactions: NHN



So I'd assume 04987 is cylinder 4.
Are there 4 cylinders/glow plugs?

I can’t see why a glow plug issue would stop the car into a journey. I thought they were only used for starting in cold weather?
This is what I thought. The light just came on whilst driving on the motorway and went into limp mode.
 
Ideally swap glowplugs around to see if the issue goes, however, it shouldn't be a glowplug issue causing limp, as per above, as its only to heat cylinders on cold starts, I would say its possibly either a linked loom fault, dpf, something common to limp & glowplugs so to speak.

I'd be surprised if a glowplug fault causes this, only one way to know tbh, 2 down does seem strange, but its an 08, so you never know.
 
  • Like
Reactions: owenjt
Might be worth getting someone with vcds to double check your error codes, and do a full scan in case there are other codes that aren't being picked up with Carista
 
Ideally swap glowplugs around to see if the issue goes, however, it shouldn't be a glowplug issue causing limp, as per above, as its only to heat cylinders on cold starts, I would say its possibly either a linked loom fault, dpf, something common to limp & glowplugs so to speak.

I'd be surprised if a glowplug fault causes this, only one way to know tbh, 2 down does seem strange, but its an 08, so you never know.
I've just phoned my local garage and they think it's possible an issue with the glow plugs has caused the dpf not to regenerate which is why the car has gone into limp mode. Best case scenario would be needing to replace faulty glow plugs and do a dpf regen.

Unfortunately I don't have the tools/knowhow to change the glowplugs around so I think I'll have to book it into the garage and let them sort it out.
 
Last edited:
I had the exact same issue where the glow plug light went on and the car went into limp mode. For my car it turned out to be that the turbo needed replacing.

if that is the case, make sure the clamp between the turbo and the DPF is replaced with an Audi original one from the dealership(£20).

I hope it’s not you’re turbo(costly).
 

Attachments

  • ED42BA9F-C8D3-4E46-806C-2D2BA3075B75.jpeg
    ED42BA9F-C8D3-4E46-806C-2D2BA3075B75.jpeg
    242 KB · Views: 78
Car has now been fixed. The garage ran their diagnostics and it came up with the following fault codes:

P067100 CYLINDER 1 GLOW PLUG CIRCUIT ( STATIC )
P067400 CYLINDER 4 GLOW PLUG CIRCUIT ( STATIC )

They've now replaced all four glow plugs and all seems to be working fine. Not a cheap job at £400+ but guess it's better than finding I need a new DPF or turbo!