Guru's Help please. A5 BRM Engine speed sensor, ECU & grounds

srptdi

Well-known member
Joined
Aug 3, 2005
Location
nj
TDI
2005.5 jetta black
I would like to thank Bob S with his original post about the chafing of the wiring in the engine harness.My car has been trouble free for 200,000 miles until last week,when I experienced bucking and stalling.I got the code p0726 and thought it was a sensor until I read this thread.I repaired the wires and its running fine again.I would also like to thank everyone who helps to keep our sometimes temper mental cars going.
 

brianstrange

Veteran Member
Joined
Aug 22, 2006
Location
Tyngsboro, MA
TDI
2006.5 Jetta DSG Auto Pkg 1
please take the time to report your issue to NHTSA


http://www.nhtsa.dot.gov

I would like to thank Bob S with his original post about the chafing of the wiring in the engine harness.My car has been trouble free for 200,000 miles until last week,when I experienced bucking and stalling.I got the code p0726 and thought it was a sensor until I read this thread.I repaired the wires and its running fine again.I would also like to thank everyone who helps to keep our sometimes temper mental cars going.
 

lowrider

Member
Joined
Aug 26, 2006
Location
Grand Junction, CO
TDI
2006 Jetta (sold)
I too have the dreaded intermittent stumble on my '06 TDI. I will also follow up with NHSTA, but I would like to check on the chafed wire syndrome. However, in order to get to the wire looms I need to remove the air filter box which I'm having a problem with. Can anyone offer some pointers on how to remove this air box?
This is the fastener I'm having trouble with. Are there any others like this?
 

Bob S.

Top Post Dawg
Joined
Aug 17, 2006
Location
Central MD.
TDI
A B4V, some ALHs & BRMs
I can't get the full perspective from the photo, but assuming what I am seeing it the drivers side of the air box with the vehicle front at the photo top and fuse panel at the photo lower end, my memory is that it is the 10mm hex head bolt in the lower center of the photo, just under the black sheathed red conductor.

If you don't have on, order a Bentlys from one of the trusted vendors. It is well worth the investment.
 

lowrider

Member
Joined
Aug 26, 2006
Location
Grand Junction, CO
TDI
2006 Jetta (sold)
......the 10mm hex head bolt in the lower center of the photo, just under the black sheathed red conductor.

If you don't have on, order a Bentlys from one of the trusted vendors. It is well worth the investment.
Thanks for the reply. The 10mm hex head bolt fastens the battery tray. The problem is at the center of the photo. The center of the black "fins" has a molded rubber top. When I move the tray back and forth, the top wiggles independently of the finned part. I'm inclined to think it's only is a centering type of a fastener and when I fully remove all the other bolts it may just be resting on that platform. However, I don't want to experiment without knowing for sure. I have the FSM, but it doesn't cover this removal.

I'm hoping some here would have some first hand experience at removing the air box.
 

sfr709

New member
Joined
Jul 11, 2012
Location
Halifax, Canada
TDI
2006 Jetta 5 speed
Hey I've got a similar problem, and have P0726 as well. It started I had been away for a couple of weeks with work, got back jumped in the car and I was driving home, and after about 10 mins in the car sputtered a bit the tach and speedometer dropped off and she shut down, both the alt and battery seem to be running fine, but it would just keep turning over... Next morning started up fine... Ran perfect for another 10 mins started to almost hiccup and shut off again... I glanced over the wiring it all looks fine and the speed sensor is seated. About two weeks before I left I had the timing belt done, but prior to leaving it was fine.
 

D-Cell_Mekanick

Veteran Member
Joined
May 23, 2009
Location
Sandwich, IL
TDI
2015 Honda Civic SE
Just bringing this problem back to the top. My 06.5 diesel edition has wire chaffing also, the new harness will be here the beginning of next week. After I verify the new harness has fixed the extended cranking time on hot starts that my car is having, I will be reporting the problem to the nhtsb. Thank you all for your efforts with this problem.
 

D-Cell_Mekanick

Veteran Member
Joined
May 23, 2009
Location
Sandwich, IL
TDI
2015 Honda Civic SE
I changed the harness out, took a bit longer than I thought it was going to. After all that work I still have the hot start problem. But at least now I can eliminate the harness as brin the problem. Does anyone know how to check the cam position sensor?
 

Bambaataa

Veteran Member
Joined
Mar 2, 2012
Location
KW, On
TDI
06 Jetta BRM 6MT; '15 Golf Sportwagen TDI GSW
No Chaffing on my harness (its completely wrapped in electrical tape with no chaffing on the tap itself ). Is there a way to test and confirm the sensor as the culprit before i replace it?


 

brianstrange

Veteran Member
Joined
Aug 22, 2006
Location
Tyngsboro, MA
TDI
2006.5 Jetta DSG Auto Pkg 1
The chaffing would be taking place under the tape. It's essentialy caused by the wires vibrating against each other from being wrapped too tight.
 

Bambaataa

Veteran Member
Joined
Mar 2, 2012
Location
KW, On
TDI
06 Jetta BRM 6MT; '15 Golf Sportwagen TDI GSW
Because of the circumstances surrounding the failure (it failed driving at 100KM/hr during a very heavy rainfall and the tape around the wiring was perfectly dry when i opened it up), I'll rather check the sensor first...
 

PDJetta

Top Post Dawg
Joined
Nov 6, 2003
Location
Northern Virginia
TDI
'04 Jetta GLS TDI Pumpe Duce Platinum Grey w/ Leather
No Chaffing on my harness (its completely wrapped in electrical tape with no chaffing on the tap itself ). Is there a way to test and confirm the sensor as the culprit before i replace it?
One thing you can do is directly wire the sensor to the ECU harness plug at the ECU, using VW repair wires and bulk electrical wire and rule out the wiring. You never know, maybe the wire has an internal break from the wire supplier, or was flexed too much at the factory.

--Nate
 

DanG144

Top Post Dawg
Joined
Aug 2, 2007
Location
Chapin, South Carolina, USA
TDI
2005 A4 Jetta 5spd
I am pretty sure I posted the voltage and resistance readings for the sensor and plug years ago. If you cannot find them, let me know; I can take the measurements again easily enough.
 

Bob S.

Top Post Dawg
Joined
Aug 17, 2006
Location
Central MD.
TDI
A B4V, some ALHs & BRMs
P0322 Engine Speed circuit input no signal. (<75 rpm).

If this is really out of service an ALH will use the needle lift sensor as a backup, and will continue to run (it is not clear if it will start without the engine speed sensor.) The BEW PD has no backup (even though it tracks the CAM speed as well!) and will not run.

My Engine speed sensor (2005 BEW PD) reads 561 ohms pins 1-2,or pins 2-1 (polarity made no difference). The repair manual calls for "0.7 to 1000K ohms" across pins 1-2. Like I said, I had 561 ohms on a known good one. The repair manual also has you check that there is an open circuit between pins 1-3 and 2-3, expecting infinite ohms. My fluke rs iead greater than 6 megohms.

While I suspect the same sensor is used on the BRM, I do not know for sure.
Dan, Yes you did. I trust you had a good GTG.
 
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dieselmax

Member
Joined
Oct 24, 2012
Location
Montana
TDI
2003 Jetta and 2006 Jetta
I have a 2006 TDI Special Edition and have had 2 recent situations with my car stalling on me. The first time was driving through a very wet snow storm near East Glacier, MT. My car suddenly stalled as I was traveling at approximately 60 MPH. I was able to pull off the road onto a Farmer's access road to his ranch. I tried a few times to restart the vehicle and it just sounded like it was not getting any fuel. I then called my mechanic, John at Celtic Motors in Kalispell, MT and he advised waiting for a little while longer to see if it may start again due to the wet conditions. In the meantime, I started making calls to arrange for a tow truck to pick me up. As I was waiting for the tow truck to call me back to confirm my location, I attempted to start the car again. It would start and run for a short time (5-20 seconds at most) then stall again. After approximately 30 minutes since I had to turn off the road, it had finally started and I let it idle for at least 10 minutes without the car stalling that I felt it may be fine to start driving again. I called John at Celtic Motors back and discussed what had transpired since my last conversation with him 40 minutes prior. He stated it should be fine and it was totally fine until I recently stopped at the car wash to wash some of the sand and hydro chloride off that the MT HWY's are always covered with. I used the Engine cleaner which is a very light green spray and then rinsed it quickly with the high pressure rinse. The car started immediately after I was done washing but was only able to get a 1/4 mile from the car wash when the exact same symptoms appeared as I was driving through a wet snow storm. The car started to stall and eventually was able to coast into a farmer's entrance to a field. I waited for at least 30-40 minutes trying to restart every 10 minutes or so. The car did not show any signs of restarting this time so I had my wife come pick me up thinking the car may start again if i left it overnight as I had read in some of the posts on this thread. The car did not start the next day and I had to have a tow truck come pick up the car and take it to Celtic Motors. Shortly after dropping the car at Celtic Motors, John attempted to start the car and it started immediately. My guess is the air passing through the engine compartment as it was being towed on top of a flat bead was enough to dry whatever sensors were wet was what made it start. The car is running fine again and it's still a mystery!!
 

DanG144

Top Post Dawg
Joined
Aug 2, 2007
Location
Chapin, South Carolina, USA
TDI
2005 A4 Jetta 5spd
There may be some codes that will help you figure it out, even if you got no CEL.

So I would read the codes with a VCDS or other system that can get all the VW codes (auto parts store readers typically cannot.)

How did it stall? Run poorly or stop as if you turn off a switch?

Do you still have your lower and side engine covers in place?
 

Emil

Active member
Joined
Jun 19, 2011
Location
Mississauga
TDI
04 jetta wagon - sold , 06 Jetta TDI Sedan - for sale , 05 Passat TDI wagon- sold , 12 Golf TDI SW, 10 Golf TDI SW- new
Same story here . After heavy snow plowing ( not on purpose ) with the car no start in the morning after it was in the garage for the night.
Oil light blinking, plugs light and ECS light on. No RPMs on dash . P0726 code.
Wiggled the harness .. and all worked fine.
Opened up the harness and several wires had chaffing on them and water at the lowest point of the harness.
Repaired it all and for now no problems. Car runs as good as new .

And by the way it did start up after a while and could be driven before the repair . It just needed a LOT of cranking .


Thanks a lot to the contributors on this site .
 
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