Update on a P0546 fault and car losing power

[Fanty111]

 

 

Happy Bank Holiday everyone,

 

Following on from my previous post about my the issues my Fabia has, I wanted to share an update and seek some further advice.

 

I want to disregard the Info I posted in my previous thread about the fault code and take this on face value

 

When the car is stationary and is revved the car is fine. However, when I started driving I'm losing power intermittently. As soon a I go back to being stationary there I no issue and can rev fine.

 

Any further pointers?

[nta16]

If you don't trust the scan tool you used before then use a VW specific scan tool or see if there's anyone local with a VCDS or other VW suited machine to do a full report for you and perhaps delete any error codes to see which immediately return.

 

List of VCDS Owners - 

https://www.google.com/maps/d/viewer?mid=1Td73_uUUqscV3nRm5br_o89PmBU&msa=0&ll=21.259901462991746%2C83.39240985000004&z=2

 

[Fanty111]

2 minutes ago, nta16 said:

If you don't trust the scan tool you used before then use a VW specific scan tool or see if there's anyone local with a VCDS or other VW suited machine to do a full report for you and perhaps delete any error codes to see which immediately return.

 

List of VCDS Owners - 

https://www.google.com/maps/d/viewer?mid=1Td73_uUUqscV3nRm5br_o89PmBU&msa=0&ll=21.259901462991746%2C83.39240985000004&z=2

 

I've had 2 diffident readers in that flag the same issue. When the code is cleared and I start driving again the issue returns like its never been away

[nta16]

If you trust the two readers for the car's VW program then as I remember the photo you showed it was for  the Exhaust Gas Temperature Sensor but I can't remember you referring to or sorting that particular sensor or it connections or wiring, but I might be wrong and I don't want to go in circles, just wanted to post the list and leave the rest to other posters that know what I don't, which is a lot. 

 

Hope you sort it soon to your satisfaction, cheers.

 

Edited 1 May, 2023 by nta16
typos and wording

[Fanty111]

11 minutes ago, nta16 said:

If you trust the two readers for VW program then as I remember the photo you showed was for it the Exhaust Gas Temperature Sensor but I can't remember you referring to or sorting that particular sensor or it connections or wiring but I might be wrong and I don't want to go in circles, just to post the list and leave the rest to other posters that know what I don't, which is a lot. 

 

Hope you sort it soon to your satisfaction, cheers.

 

Thank anyway pal

 

I'm not convinced it's the DPF at this point. I too am going around in circles with this. I just hope this isn't a death sentence for it

[UrbanPanzer]

So have we replaced the EGT sensor or "atleast" checked the wiring to it / them ?

[Fanty111]

1 hour ago, UrbanPanzer said:

So have we replaced the EGT sensor or "atleast" checked the wiring to it / them ?

When you say EGT sensor do you mean the lambda sensor or is this a different component?

[sepulchrave]

EGT sensor is a thermocouple for measuring temperature, Lambda sensor is for measuring oxygen content in a gas, two totally different things.

[Fanty111]

15 minutes ago, sepulchrave said:

EGT sensor is a thermocouple for measuring temperature, Lambda sensor is for measuring oxygen content in a gas, two totally different things.

Where is the EGT sensor located?

[sepulchrave]

17 minutes ago, Fanty111 said:

Where is the EGT sensor located?

 

There are usually two or three, there can be one before the turbo, one before the DPF and one after the DPF, there is generally only one Lambda sensor before the DPF though.

Edited 1 May, 2023 by sepulchrave

[Fanty111]

On 01/05/2023 at 15:19, sepulchrave said:

 

There are usually two or three, there can be one before the turbo, one before the DPF and one after the DPF, there is generally only one Lambda sensor before the DPF though.

I replaced the EGT sensor and its didn't make an iota of difference. Car is still in and out of limp mode. Genuine VW part too, not aftermarket OEM

[Breezy_Pete]

Which one did you change? What colour connector?

[Fanty111]

22 hours ago, Breezy_Pete said:

Which one did you change? What colour connector?

It's was the brown G235 I believe

 

Edit: car is now reading p0132 and p0473

Edited 14 May, 2023 by Fanty111

[Breezy_Pete]

According to wiring diagrams for BMS engine code (is this what yours is?), exhaust gas temperature sender No.1 is G235, but has a black connector;

No.2 is G448 and has a brown connector; No.3 is G527 and has an orange connector.

 

So it's not massively clear to me whether you've changed the correct one or not.  The fact that you now have codes for lambda sensor and exhaust gas pressure sensor suggests maybe you have got the right temperature sensor, but other issues.

 

 

[sepulchrave]

I imagine the Lambda and pressure sensor are badly fouled with soot because the exhaust hasn't been getting hot enough due to the faulty temperature sensor and also being stuck in limp mode for too long.

[Fanty111]

8 hours ago, sepulchrave said:

I imagine the Lambda and pressure sensor are badly fouled with soot because the exhaust hasn't been getting hot enough due to the faulty temperature sensor and also being stuck in limp mode for too long.

What is your suggestion?

11 hours ago, Breezy_Pete said:

According to wiring diagrams for BMS engine code (is this what yours is?), exhaust gas temperature sender No.1 is G235, but has a black connector;

No.2 is G448 and has a brown connector; No.3 is G527 and has an orange connector.

 

So it's not massively clear to me whether you've changed the correct one or not.  The fact that you now have codes for lambda sensor and exhaust gas pressure sensor suggests maybe you have got the right temperature sensor, but other issues.

 

 

My engine code is BNV if that makes a difference?

[Breezy_Pete]

6 hours ago, Fanty111 said:

My engine code is BNV if that makes a difference?

Biggest difference ever...

I really wish people would start out with engine code on engine-related enquiries.

 

Not sure what your code reader is playing at, nor what parts you've really been swapping, but according to circuit diagrams and parts catalogue a BNV engine has no DPF, so no exhaust gas temperature, exhaust pressure or lambda sensors. 

Message me with your VIN please, for checking things out.

And find a local member with VCDS to do a proper fault read (or get VCDS lite yourself, which will work on your car, for just the price of a cheap kkl cable) 

[Fanty111]

12 hours ago, Breezy_Pete said:

Biggest difference ever...

I really wish people would start out with engine code on engine-related enquiries.

 

Not sure what your code reader is playing at, nor what parts you've really been swapping, but according to circuit diagrams and parts catalogue a BNV engine has no DPF, so no exhaust gas temperature, exhaust pressure or lambda sensors. 

Message me with your VIN please, for checking things out.

And find a local member with VCDS to do a proper fault read (or get VCDS lite yourself, which will work on your car, for just the price of a cheap kkl cable) 

I'm 99% certain it does have a DPF. There is a light that comes on indicating there is DPF which, hasn't come on in some time. From what I've been reading following this comment the BNV does has DPF on some models. What was curious though is that when my mechanic tried to force a regen using his snapon diagnostic it didn't give him the option. 

 

Mechanic has replaced the lambda and the egt not me

[Breezy_Pete]

13 hours ago, Breezy_Pete said:

Message me with your VIN please, for checking things out.

I'll be able to see if it was or wasn't built with a DPF, and associated sensors.

[Fanty111]

1 hour ago, Breezy_Pete said:

I'll be able to see if it was or wasn't built with a DPF, and associated sensors.

Will PM it across now

[Fanty111]

23 hours ago, Breezy_Pete said:

I'll be able to see if it was or wasn't built with a DPF, and associated sensors.

Interesting development this evening.

 

To clarify for those following it has a BMS engine not BNV

 

The car has been stagnant for a week now. I collected it from my father in laws for the 5 min journey home. I screamed its head off in 2nd gear and the it smelt awful. This was followed a large ploom of blue smoke. Still went into limp intermittently a couple times but I continued to push the revs, car continued to stink. I then had 15 minutes uninterrupted driving for the first time in a month.

 

Tonight I'm going to push it on the motorway to see if it finally clears once and for all!