ECM replacement

Leopard

Member
Joined
May 27, 2021
Location
Kingsport, Tennessee
TDI
Jetta 2011 Sportwagen
Good morning fellow TDI'ers! New to the forum and only now starting to explore it, but what a great resource it is.
Well, this is my issue and from what I'm seeing it has not been covered here yet... I own a Jetta TDI Sportwagen 2011 that has been very reliable up until it recently reached 135K miles and problems started happening. After a replacement of the second fuel injector and after having all fuel seals redone at my local trusted mechanic, I was able to drive it only for another 1000 miles before the engine completely downgraded with heavy white smoke. The car can only do 3mph these days and is barely moving.

All current engine codes relate to cylinder 3 misfiring (P0303), injection timing (P020C) and torque difference (P1006). My mechanic, trying to get to the cause of it all, switched fuel injector #3 with #2 and the faults remain. He has also checked wiring to fuel injector #3, no issues. He is convinced the car will need a reprogramming of its ECM

Has anyone had any luck with ECM reprogramming? Any tech savvy diesel gurus out there? I have tried to take car to the local dealership and after they did a compression test they told me it is not worth figuring out what is wrong with cylinder #3, it will need a new engine. Price tag $6,000 out the door. Yeah, right.

Any advice much appreciated!
 

MrCypherr

Veteran Member
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Sep 3, 2012
Location
Ontario
TDI
Mk6 Wagon
Has the timing been touched for any reasons? Has he checked the injection pump timing just to be sure?
 

jetta 97

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Dallas (McKinney) ,TX ,USA
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2 X Jatta MK5 2006
I agree with oilhammer, I doubt update will fix it . I do not think your mechanic has good experience with TDI.
When he swap injectors did he CODE injectors , On Common Rail you can not just like that swap injector ..


BTW, If you did Diesel gate emission update your car is under warranty . Just take it to dealer and let them fix it for free.
Any Check engine light will be under warranty .
 

KERMA

Vendor , w/Business number
Joined
Sep 23, 2001
Location
here
TDI
99 beetle and 04 jetta
It's either an injector and or glow plug sensor

Do you have VCDS? There are some things you can do to troubleshoot further

MVB 140, 143 at load, to identify the offending cylinder Default combustion position (timing, MVB 143) in a failed sensor is -18 (atdc) so this will be a dead giveaway. Otherwise there will be significant torque deviation from the others (MVB 140). Just like the SRC at idle (MVB 13) everyone is used to looking at. But this is best observed under load, not idle... although idle can provide information also

Swap the position of the suspected bad sensor and or injector with one of the others, to see if the fault follows the sensor/injector. Remember if you swap injectors positions, enter the IMA/IVA value for that injector so it's not using the wrong value for that injector.
Swap the sensors around first, since injector failures are not as common as sensor failure.
if this confirms the bad part, replace it.

The VCDS compression check uses the glow plug sensors, so if there's a bad sensor it will incorrectly indicate as low compression using this method. Best way to check compression is the old fashioned way, with a mechanical gage.

But it's likely just a bad injector(s) and or glow plug sensor(s). Most likely a bad glow plug sensor (maybe two)
 

JELLOWSUBMARINE

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2011 Jetta Sportwagen, 6M, red/tan, navi, pano, 83 5m diesel pickup, 82 p/u trailer,.04 5.5 TDI Passat wagon (gone), 80,81,82 diesel p/u (gone), 80,82 sportruck (gone), 59 passthru bus (long gone), 79&87 westy (gone), 57 baja bug (long gone), 73 914
I

BTW, If you did Diesel gate emission update your car is under warranty . Just take it to dealer and let them fix it for free.
Any Check engine light will be under warranty .
My 2011 is just out of warrenty by the 10 year in service cutoff. I guess it is possible the o.p. is under
 

Leopard

Member
Joined
May 27, 2021
Location
Kingsport, Tennessee
TDI
Jetta 2011 Sportwagen
Great pointers, thank you for all the help! So yeah, this one is out of warranty sadly. Not sure if you can manipulate the fuel injection timing via VCDS but I will check the MVBs and get back to you. Also I don't think my mechanic has done anything with the glow plug sensors so far - thanks again!
 

JELLOWSUBMARINE

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Location
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2011 Jetta Sportwagen, 6M, red/tan, navi, pano, 83 5m diesel pickup, 82 p/u trailer,.04 5.5 TDI Passat wagon (gone), 80,81,82 diesel p/u (gone), 80,82 sportruck (gone), 59 passthru bus (long gone), 79&87 westy (gone), 57 baja bug (long gone), 73 914
It's either an injector and or glow plug sensor
(.
Swap the sensors around first, since injector failures are not as common as sensor failure.
if this confirms the bad part, replace it.

But it's likely just a bad injector(s) and or glow plug sensor(s). Most likely a bad glow plug sensor (maybe two)
While my 2011 was under extended coverage it threw codes for 2 glow plug sensors. It seems to be a weak spot on these cars/engines(?) I've read more than a few post on the harness being a resistance issue and needing replaced.. Probably a good direction to confirm proper function.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
There is a TSB about the cylinder pressure sensors... but they won't cause any driveability issues nor clouds of white smoke. So that is not the problem here.

Again... compression test. Quick, easy, and at least you'll know 100% that the engine PROPER is healthy.
 

JELLOWSUBMARINE

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Mar 3, 2014
Location
yes
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2011 Jetta Sportwagen, 6M, red/tan, navi, pano, 83 5m diesel pickup, 82 p/u trailer,.04 5.5 TDI Passat wagon (gone), 80,81,82 diesel p/u (gone), 80,82 sportruck (gone), 59 passthru bus (long gone), 79&87 westy (gone), 57 baja bug (long gone), 73 914
My 2011 is just out of warrenty by the 10 year in service cutoff. I guess it is possible the o.p. is under
I am talking about Diesel Gate Emission extended coverage , not regular warranty .
Sorry for getting back late, hope this helps
My 11' CPO actually had 6 different warrenties. (purchased 2?/19 w/ 69,464 miles)
1 T.D.I. extended drivetrain 123,464 or 6/20
2 clockspring 120,000 or 11/20
3 C.P.O. 94,000 OR 11/20
4 exhaust flap 120,000 or 11/20
5 HPFP 120,000 or 11/20
6 emmisions 126,000 or 5/21
 

Leopard

Member
Joined
May 27, 2021
Location
Kingsport, Tennessee
TDI
Jetta 2011 Sportwagen
So... Checking MVB values these are my readings on VCDS for groups 140 & 143

Could that be a failed glow plug sensor?

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 01: Engine (03L 997 030 B)

11:45:02 Group 140
78.0 Nm Torque
105.0 Nm Torque
0.0 Nm Torque
87.0 Nm Torque

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 01: Engine (03L 997 030 B)

11:46:24 Group 143
13.1 °ATDC Ign. Timing
13.5 °ATDC Ign. Timing
18.4 °ATDC Ign. Timing
13.5 °ATDC Ign. Timing
 

Leopard

Member
Joined
May 27, 2021
Location
Kingsport, Tennessee
TDI
Jetta 2011 Sportwagen
My apologies for the late response - they did check the compression (not sure how, and if the testing involved VCDS) at the local dealership and these are the values they gave me:

#1 25.4 bar
#2 27.5 bar
#3 18.2 bar
#4 25.7 bar

Oilhammer does that indicate a healthy engine? According to the dealer, engine needs to be replaced, according to the local mechanic 18.2 bar are plenty to fire the 3rd cylinder???
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
That is where that issue with #3 is, clearly.

New spec is: 25.0 to 31.0 bar

Wear limit is: 19.0 bar

Permissible difference between all cylinders: .................... maximum 5.0 bar

So yeah, you need a new engine or that one rebuilt. I have no idea what happened, if you took the engine apart I am betting it would be obvious that something is tooefed with #3 piston/rod/cylinder/valves.
 

KERMA

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Sep 23, 2001
Location
here
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99 beetle and 04 jetta
If you want to do a compression check, use a MECHANICAL gage not VCDS.

VCDS compression check uses the cylinder pressure sensors

18.4 degrees is the replacement value for a failed pressure sensor.

swap around the glow plugs between #3 and one other, see if the 18 degrees reading moves with the glow plug.

If the 18.4 degrees moves with the glow plug, replace the glow plug

Might as well try the swap around test if you are going to pull the plugs for a compression test, anyway
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
It has a mechanical problem. The original post stated sudden loss of power, heavy white smoke. That is not a cylinder pressure sensor problem. You could unplug all four glow plugs/pressure sensors, and the engine would start right up and drive you around (I know, I've done this).

The engine management does not have a "low compression" DTC, it just flagged a misfire for #3. I asked three times in this thread to do a compression test. He finally did, posted the results, and it is pretty clear that #3 cylinder is bad. We won't know what until (if) the engine is torn down, or at least the head is removed. Maybe it was some sort of injector failure (diesels can have a sort of injector failure that will blowtorch a hole right through a piston in about 30 seconds) or maybe something else.

The history of "after replacing a second fuel injector and seals, etc." leads me to believe there was some underlying cause that sent the Failboat out of the harbor, and now here we are in the middle of the ocean with a tooefed engine.

Maybe the engine never needed an injector (or injectorS) at all, but someone was just throwing parts at it. Clearly if someone suggested a control unit at this point, they really are not sure what is going on, and some basic diagnostic strategies (like a simple compression check) eluded them.
 

KERMA

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here
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99 beetle and 04 jetta
FWIW, the torque difference DTC effectively functions as a "low compression" DTC. The torque difference DTC kicks the sensor offline and substitute values are fed to that cylinder's timing and internal torque settings and diagnostics so the car can continue to run in a reduced capacity ("limp mode"). Those sensors won't prevent the car running, but it will certainly be down on power without them.

Probably well worth taking a minute to swap around the sensor to verify the problem being in the cylinder mechanicals before ripping into the head. My bad if that's already been done.
 

KERMA

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Sep 23, 2001
Location
here
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99 beetle and 04 jetta
Edit: I need to pay better attention when reading:sneaky:

BTW... IF (edit) the compression test he did was thru VCDS, using OBD (he said he wasn't sure)
This OBD compression test uses the signal from the cylinder pressure sensors.
One of the ways the pressure sensor signal is used, is to calculate individual cylinder torque output. The measured pressure (imep) inside the cylinder is directly proportional to internal torque of that cylinder. The compression test strips away various "corrections" and relies on the raw pressure signal instead of calculating torque from the signal.

Any definitive compression test needs to be MECHANICAL the old fashioned way, with a guage. Otherwise it may be relying on an unreliable sensor that has possibly been kicked offline by the fault, which could be showing substitute values in diagnostics. eg = 0
 
Last edited:

Leopard

Member
Joined
May 27, 2021
Location
Kingsport, Tennessee
TDI
Jetta 2011 Sportwagen
Oilhammer & KERMA thank you for the back and forth, very informative. Indeed I asked again how the compression test was done, VW dealership stated with a "specialized diagnostic tool provided by VW" and that it was "mechanical". Not absolute sure if that means that no sensors were involved. On top of that I did not talk to the mechanic who performed the test but to the woman who runs the show at the front desk, whatever her opinion is worth.
An additional curveball to the story, car broke down less that 80 miles after I filled up with fuel in a pretty sketchy, independently ran truck stop in northern Kentucky. I didn't think much about it at the time, but after I drove by the same truck stop about a month later, it all came back to me sending shivers down my spine. If fuel's to blame then that's a real horror story for the poor engine.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Yep, bad fuel can cause an injector to stick or do something it shouldn't, and that can most certainly tooef an engine. Rare, but it happens.
 

KERMA

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Joined
Sep 23, 2001
Location
here
TDI
99 beetle and 04 jetta
or perhaps a failed CP sensor followed by bad fuel nuking the HPFP (separate failures confounding diagnosis)

Smoke and low power fits with failed HPFP

Of course anything's possible, but I'm having a hard time accepting the possibility of a single cylinder spontaneously self-destructing in the absence of a separate, obvious mechanical event like a timing belt failure for example or really bad rattling noises or something.
 
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