Glow plug circuit open / fault code

[JimbobT6]

Hi,

Randomly getting the orange engine dash warning on my 2020 T6 204hp.

I can clear it with Carista and the engine warning lamp disappears. Not getting any limp mode or anything.

The fault code is suggesting open circuit / fault on cylinder 1 glow plug, but I am not experiencing any issues and it’s random. Happened twice In the past 3 days after being left stationary at centre parcs for a week.

Any ideas?

Thanks

 

[mmi]

it’s random. Happened twice In the past 3 days

Random??? The dash warning light or the fault code? Typically emission faults stay in pending state for a few start-ups before turning dash warning light on.
Besides pre-heating the glow plugs are on after engine start-up for a few minutes - reducing emissions.

 

[JimbobT6]

The dash warning light and fault code are clearly linked to the same signal…

I meant random as in…. It randomly does it..
If there was a genuine open circuit fault on a glow plug then I’d expect it to throw that fault regularly. Ambient temperature is relatively consistent so glow plug load shouldn’t be different at this time of year. I’ve checked for loose plugs, so I guess it could just be the glow plug starting to break down on cylinder 1…?

 

[mmi]

Have you checked the fault code after each and every journey?
Although the dash warning light and fault code are linked but whenever the code is cleared, it usually takes a few driving cycles to confirm the fault and manifest as warning light.

 

[JimbobT6]

Thank you, you are totally right the fault is there every time I scan, but must only be throwing engine dash light after a set amount of ignition starts.

I appreciate the education

 

[LBird80]

Did you solve this. I have the same issue but glow plug circuit 2.
Engine management light comes on after a few trips but the van runs fine.

 

[Celticrsmith]

Did you solve this. I have the same issue but glow plug circuit 2.
Engine management light comes on after a few trips but the van runs fine.

Same here. What’s the solution/fix?

 

[LBird80]

I ended up changing the glow plugs and it’s all cleared.
I got all 4 plugs changed whilst it was in instead of just the 1 on glow plug circuit 2.
I believe you can just change the one if you want.
3 of the plugs cost about £15-£20 each but the one on cylinder three has a pressure sensor built in and that glow plug costs about £200 on it’s own from memory.

 

[Celticrsmith]

Can I ask how much it costs to just get the 1 changed? Mine is the P0672 so thankfully not the sensor chamber, but reading on here, looks like I just need to change the 1. Are they a bugger to replace?

 

[LBird80]

I’m lucky in that my friend owns a garage and I get mates rates so not sure what a typical garage would charge.
I’ve read that they can get stuck and snap which is then a bugger, but apparently plenty of wd or similar and remove them when the engine is warm makes it easier.
You should reinstall them with the engine cold.

Also there is a nack to releasing them.
Slowly undo it, if and when it gets tough to undo, tighten it back up and then undo again and repeat. Don't try and force it past the tight spot as that’s when they’re likely to snap.

 

[Celticrsmith]

Cheers mate. Defo not something I’m prepared to tackle myself so I’ll likely need to go to an independent mechanic to fix it.
Out of curiosity, how long can it be driven like this for and is it likely to affect the others? ¯\_(ツ)_/¯

 

[DXX]

You also need to thoroughly clean the area around the glow plug, degrease and vacuum out.
As well as avoiding dropping debris into the cylinder and grit will wreck the threads. I would start soaking with penetrating oil daily a couple of weeks before if possible.

 

[LBird80]

Cheers mate. Defo not something I’m prepared to tackle myself so I’ll likely need to go to an independent mechanic to fix it.
Out of curiosity, how long can it be driven like this for and is it likely to affect the others? ¯\_(ツ)_/¯

They are only used to start the engine. Once the engine is warm they don’t do anything. At worst your van will just be a bit lumpy when you first start it and then you won’t notice anything. I didn’t anyway.

After mine first started we went away down south in the van and travelled around without any issues at all so I think it’s not something you have to rush to get sorted and it would be ok to drive with until you do. Obvs the colder weather might bring some challenges when starting the van if you haven’t got it sorted by then.

I don’t think a fault on one can affect the others.

 

[DXX]

Cheers mate. Defo not something I’m prepared to tackle myself so I’ll likely need to go to an independent mechanic to fix it.
Out of curiosity, how long can it be driven like this for and is it likely to affect the others? ¯\_(ツ)_/¯

Have you put an multimeter on the glow plug to check it is open circuit, it could be a wiring issue?

 

[Celticrsmith]

No I haven’t tried that. I’m not very mechanically minded so wouldn’t know where to start. The last EML was the coolant sensor which turned out to be a broken wire so fingers crossed the theme runs the same

Cheers

 

[DXX]

No I haven’t tried that. I’m not very mechanically minded so wouldn’t know where to start. The last EML was the coolant sensor which turned out to be a broken wire so fingers crossed the theme runs the same

Cheers

OK it’s worth finding some body with a multimeter to check continuity, takes a minute and could save removing a glow plug.

 

[Phil_j89]

They are only used to start the engine. Once the engine is warm they don’t do anything. At worst your van will just be a bit lumpy when you first start it and then you won’t notice anything. I didn’t anyway.

After mine first started we went away down south in the van and travelled around without any issues at all so I think it’s not something you have to rush to get sorted and it would be ok to drive with until you do. Obvs the colder weather might bring some challenges when starting the van if you haven’t got it sorted by then.

I don’t think a fault on one can affect the others.

They are activated during running too, on newer tdis.

 

[Alanmh]

They are activated during running too, on newer tdis.

That’s interesting. I had the light come on on the way to Leeds at Christmas. Long journey in very wet and windy conditions. Could this prompt glow plugs to come on? I haven’t got an obd2 reader at the moment. Maybe I should get one.