EGR Fault Help

Paynewright

Paynewright

Senior Member
VIP Member
T6 Legend
All,

Had a fault last week and cleared it now its back. Both times the fault popped up on starting and there seemed to be a slight hesitation to starting. Usually it fires up no problem and did after I cleared the fault. It had a new battery last year but I'll check the voltage in daylight tomorrow. Its had two good long runs in the last couple of weeks so should be well charged.

Any advice / guidance would be appreciated as I have no idea how to interpret the data ie what is good or bad for the readings. There are also so many threads on the topic so while I'm trawling them for information I thought I'd post the VCDS log...


2 Faults Found:

15560 - EGR Sensor 1

P046C 00 [01101100] - Implausible Signal

Intermittent - Confirmed - Tested Since Memory Clear

Freeze Frame:

Fault Priority: 2

Fault Frequency: 1

Mileage: 59072 km

Date: 2091.01.08

Time: 12:50:47



Engine RPM: 0.00 /min

Normed load value: 0.0 %

Vehicle speed: 0 km/h

Coolant temperature: 36 °C

Intake air temperature: 25 °C

Ambient air pressure: 1000 mbar

Voltage terminal 30: 12.156 V

Unlearning counter according OBD: 40

Mass airflow sensor 1 bank 1 airflow: raw value: 0.0 mg/stroke

Exhaust recirc.valve 1 bank 1: posit.feedback - Specified value: 3.07 %

Exhaust recirc.valve 1 bank 1: posit.feedback - Actual value: 3.19 %

Exhaust recirc.valve 1 bank 1: posit.feedback - Offset closed: 0.00 %

Exhaust recirc.valve 1 bank 1: posit.feedback - Raw voltage: 2.500 V

EGR vacuum regulator solenoid valve 1 bank 1: res. Cooling mode stop: 2.340 V

EGR vacuum regulator solenoid valve 1 bank 1: res. Bypass operation stop: 2.560 V



15916 - Cylinder 1 Glow Plug Circuit (Q10)

P0671 00 [11101100] - Electrical Fault

MIL ON - Intermittent - Confirmed - Tested Since Memory Clear

Freeze Frame:

Fault Priority: 2

Fault Frequency: 1

Mileage: 59072 km

Date: 2091.01.08

Time: 17:56:10



Engine RPM: 0.00 /min

Normed load value: 0.0 %

Vehicle speed: 0 km/h

Coolant temperature: 20 °C

Intake air temperature: 25 °C

Ambient air pressure: 990 mbar

Voltage terminal 30: 11.882 V

Unlearning counter according OBD: 40

Pre-glow time: 2.5 s

Glow status: Readiness heat

Outside temperature sensor 1: B1: raw value: 13.0 °C
 
Cleared twice now and comes back almost immediately. Drives fine no stutters and accelerates as normal.

Would removing the front stainless EGR pipe and inspecting give an indication of how ‘sooty’ it is? (No Sweep jokes!)

Ian
 
Thanks - we’re away till Sunday and I didnt bring the laptop!

Will do when I get home.

Is it likely to be a glow plug needs changing?
 
Last edited:
Just had the glow plug fault on my T-Cross - it was the glow plug relay that caused it. I didn't get as far as changing glow plugs, cured with the new relay.
 
I just checked what the fault code was and googled for causes. I had had the same fault within 100 miles from new that the dealer fixed - they said control module replaced. Control module turns out to be glow plug relay in plain English!
 
@mmi

Both are back. Is this what you mean by complete engine section....


Address 01: Engine (2D2D2-CXGB) Labels:. 04L-907-309-V2.clb
Part No SW: 04L 906 056 KB HW: 04L 907 445
Component: R4 2.0l TDI H02 5950
Revision: 23002001
Coding: 0011401C430401090000
Shop #: WSC 02737 790 50316
ASAM Dataset: EV_ECM20TDI03004L906056KB 004014
ROD: EV_ECM20TDI03004L906056JT.rod
VCID: 77ABE266EF4444526E1-8022
VINID: 9E60AAAAA1D8A986001071841CC05462F7

2 Faults Found:
15560 - EGR Sensor 1
P046C 00 [01101100] - Implausible Signal
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Mileage: 59438 km
Date: 2091.01.30
Time: 17:55:58

Engine RPM: 0.00 /min
Normed load value: 0.0 %
Vehicle speed: 0 km/h
Coolant temperature: 13 °C
Intake air temperature: 27 °C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 12.101 V
Unlearning counter according OBD: 40
Mass airflow sensor 1 bank 1 airflow: raw value: 0.0 mg/stroke
Exhaust recirc.valve 1 bank 1: posit.feedback - Specified value: 3.01 %
Exhaust recirc.valve 1 bank 1: posit.feedback - Actual value: 3.75 %
Exhaust recirc.valve 1 bank 1: posit.feedback - Offset closed: 0.00 %
Exhaust recirc.valve 1 bank 1: posit.feedback - Raw voltage: 2.499 V
EGR vacuum regulator solenoid valve 1 bank 1: res. Cooling mode stop: 2.342 V
EGR vacuum regulator solenoid valve 1 bank 1: res. Bypass operation stop: 2.560 V

15916 - Cylinder 1 Glow Plug Circuit (Q10)
P0671 00 [11101100] - Electrical Fault
MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Mileage: 59438 km
Date: 2091.01.30
Time: 17:55:50

Engine RPM: 0.00 /min
Normed load value: 0.0 %
Vehicle speed: 0 km/h
Coolant temperature: 13 °C
Intake air temperature: 14 °C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 11.781 V
Unlearning counter according OBD: 40
Pre-glow time: 2.5 s
Glow status: Readiness heat
Outside temperature sensor 1: B1: raw value: 13.0 °C

Readiness: N/A
 
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Paynewright said:
@mmi

Both are back. Is this what you mean by complete engine section....
Click to expand...
Thanks - exactly the package.


This below is the fault which turned dash light on. Prime suspect is cylinder 1 glow plug.

1730048144041.png

For the 15560 - EGR Sensor 1 - P046C 00 [01101100] - Implausible Signal
you could run engine's built-in diagnostics by using VCDS - to get better view what's going on.
Please post the log files here - I'm more than happy to have a look.

The test HOW-TO in the thread below
www.t6forum.com

EGR Valve Self Test Procedure (IDE00242)- P046C?

So, I've been getting the all too common P046C fault code along with P2457 (Insufficient EGR Cooling Performance). Neither alone will flag a check engine light but combined they sometimes seem to. To try to figure out what is going on, I ran an EGR Flow test on VCDS using instruction from @mmi...
www.t6forum.com www.t6forum.com


Just for your infromation - there is a software update for your engine
Current software 04L 906 056 KB version 5950 - available version 6189
1730048720447.png

Welcome to VAG-Flashinfo!

VAG Flashfiles Informations - Version check of VAG ECUs - Update check for Audi, Seat, Skoda and Volkswagen
vag-flashinfo.de vag-flashinfo.de
 
Looks like a lot of dismantling to get to the glow plug just to test it - pondering whether to change no1 or 1, 2 and 4 (cheap ones) or the set?

That said there seems to be a hole in the cooler support frame on the top of the engine to get to #1 glow plug
 
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Paynewright said:
@mmi

Both are back. Is this what you mean by complete engine section....


Address 01: Engine (2D2D2-CXGB) Labels:. 04L-907-309-V2.clb
Part No SW: 04L 906 056 KB HW: 04L 907 445
Component: R4 2.0l TDI H02 5950
Revision: 23002001
Coding: 0011401C430401090000
Shop #: WSC 02737 790 50316
ASAM Dataset: EV_ECM20TDI03004L906056KB 004014
ROD: EV_ECM20TDI03004L906056JT.rod
VCID: 77ABE266EF4444526E1-8022
VINID: 9E60AAAAA1D8A986001071841CC05462F7

2 Faults Found:
15560 - EGR Sensor 1
P046C 00 [01101100] - Implausible Signal
Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Mileage: 59438 km
Date: 2091.01.30
Time: 17:55:58

Engine RPM: 0.00 /min
Normed load value: 0.0 %
Vehicle speed: 0 km/h
Coolant temperature: 13 °C
Intake air temperature: 27 °C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 12.101 V
Unlearning counter according OBD: 40
Mass airflow sensor 1 bank 1 airflow: raw value: 0.0 mg/stroke
Exhaust recirc.valve 1 bank 1: posit.feedback - Specified value: 3.01 %
Exhaust recirc.valve 1 bank 1: posit.feedback - Actual value: 3.75 %
Exhaust recirc.valve 1 bank 1: posit.feedback - Offset closed: 0.00 %
Exhaust recirc.valve 1 bank 1: posit.feedback - Raw voltage: 2.499 V
EGR vacuum regulator solenoid valve 1 bank 1: res. Cooling mode stop: 2.342 V
EGR vacuum regulator solenoid valve 1 bank 1: res. Bypass operation stop: 2.560 V

15916 - Cylinder 1 Glow Plug Circuit (Q10)
P0671 00 [11101100] - Electrical Fault
MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Mileage: 59438 km
Date: 2091.01.30
Time: 17:55:50

Engine RPM: 0.00 /min
Normed load value: 0.0 %
Vehicle speed: 0 km/h
Coolant temperature: 13 °C
Intake air temperature: 14 °C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 11.781 V
Unlearning counter according OBD: 40
Pre-glow time: 2.5 s
Glow status: Readiness heat
Outside temperature sensor 1: B1: raw value: 13.0 °C

Readiness: N/A
Click to expand...
Mine was the same but cylinder 2 - worth changing the glow plug relay in your case also? Easier than the glow plugs.

15918 - Cylinder 2 Glow Plug Circuit (Q11)
P0672 00 [10101111] - Electrical Fault
MIL ON - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 2
Mileage: 1624 km
Date: 2024.08.09
Time: 08:52:23

Engine RPM: 905.25 /min
Normed load value: 24.7 %
Vehicle speed: 0 km/h
Coolant temperature: 18 °C
Intake air temperature: 19 °C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 11.523 V
Unlearning counter according OBD: 40
Pre-glow time: 2.5 s
Glow status: Post-heat
Outside temperature sensor 1: B1: raw value: 17.5 °C
 
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Pull out a relay or spend hours dismantling and swearing to get at a glow plug - I know which I would chose. And did.
 
Why not try what VCDS can tell - there seem to be two tests available:

1) VCDS > Select > 01-Engine > Output Tests > IDE00231-Glow time control module​

2) VCDS > Select > 01-Engine > Basic Settings > IDE00894-Test of automatic glow time control module​

 
Last edited:
Not sure I know what I’m doing - clicked on a few parameters to test and got the following….IMG_4034.jpeg
 
I think I’m going to get a new relay / control module and while I’m changing it, check the continuity to and resistance of each of the glow plugs from the ebox. If one is open circuit it could be the plug OR the loom but next step I’ll change GPs.
 
So got a new relay and stripped out the battery etc down to the ebox. Thanks to a post by @rod_vw worked out how to release the mini fuse box from the ebox lid (basically open the fuse cover, release two tabs on the filler piece and lift out. The fuse block will now slide sideways and drop downwards freeing it from the lid.)

Pulled the current relay and with the multimeter set on 200 ohms I got the following readings by touching the connection to each glow plug and earth.

1 - 83.2
2 - 0.8
3 - 0.8
4 - 0.8

So, I dont think its the relay. Its either the glow plug #1 faulty or the wiring to it (imho).

Put the old relay back in and reassembled.

So, now I’m faced with stripping out the charge cooler, do I change No1 only (and check wiring), the cheaper 1, 2 and 4 or do all of them?

Just weighing up cost and potential bork factor with the fact I have to strip it down whether I do 1 or 4?


IMG_4082.jpeg
 
The three cheap glow plugs have been purchased and work to commence this weekend.

Couple of queries:-

I’ve seen a few posts say remove them when hot. I have the intercooler gubbins to remove first which will mean its cooled a bit. Have I just got to work fast! :)

I have coppa slip, alumslip and ceramic grease. What will be best to use? I’m leaning towards alumslip.

Wish me luck!
 
Last edited:
So, just to close this off, changing the glow plugs (#1 the faulty one and 2 and 4 which are the other cheap ones) has fixed the issue. Previously clearing the fault would see it come back immediately when the engine was started, now it is staying off.

This is the video I (mainly) followed:-


I have a couple of alterations which worked for me.

Firstly, I syphoned off coolant from the header tank - there is an outlet in the bottom of the header and I could get the drain tube quite a way down it. There was probably a litre I drained off which meant negligible coolant was lost disconnecting the hoses on the intercooler. No need for hose clamps / bungs.

Secondly, I didn’t remove the fuel rail. Plugs 1 and 2 were easy to access. Number 4 was a bit tricky and I used a UJ to remove the plug (3/8 drive) when re-installing I was a bit concerned about the UJ and whether it would possible cross thread the plug. I have a set of 1/4 drive deep sockets and found the thinner extension bar of the 1/4” set cleared the fuel rail and sensor to get square onto the plug. I was then confident of the plug threading correctly, which it did. Done finger tight using the extension bar first, before torquing up.

I used alum slip on the threads which may help for future removal. They do let go suddenly when removing!
 
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