# a4 crank position sensor location?



## pundzak (Oct 27, 2010)

just got a reading from an obd that my crank sensor is not functioning properly. i assume it needs replacing. my car stalls at low rpms. now check engine light is on. can anyone direct me to it's location? i've googled this and a couple of different locations came up. 1-front of engine block, left side, down by crank pully. 2-back of motor on driver's side, top of transmission, behind small heat shield. requires moving coolent resovoir. unless these are in fact the same location. i haven't been able to search yet. 

thanks


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## pundzak (Oct 27, 2010)

i'm good. problem solved, just started respecting the car that's all. no more trips to the dealer here i hope.


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## ocod2020 (Jan 26, 2009)

pundzak said:


> just got a reading from an obd that my crank sensor is not functioning properly. i assume it needs replacing. my car stalls at low rpms. now check engine light is on. can anyone direct me to it's location? i've googled this and a couple of different locations came up. 1-front of engine block, left side, down by crank pully. 2-back of motor on driver's side, top of transmission, behind small heat shield. requires moving coolent resovoir. unless these are in fact the same location. i haven't been able to search yet.
> 
> thanks


 hope this helps 

http://www.a4mods.com/index.php?page=webcontent/pages/enginespeedsensor.html 

the problem will get worse and leave you stranded if you don't replace it


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## pundzak (Oct 27, 2010)

perfect, thanks for the link. unfortunately this was not something i was able to fix right away, could there be permanent damage to the engine?


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## cw2899 (Apr 13, 2011)

*2005 CPS replacement*

I have the sme problem, my CPS is going/gone bad. I ordered a new one and will be replacing it this weekend....wish me luck. oh yea, I have a 2005 A4 1.8T. Any tricks about the replacement I need to know about?


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## gregg3gs (May 15, 2004)

move the coolant overflow out of your way (for easy access)


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## cw2899 (Apr 13, 2011)

*2005 CPS replacement*

Thanks, I cant believe it will be that simple. I will document this well with pics and post on Monday. By the way, I am replacing the serpentine belt as well. The tensioner is very close to the radiator! Since I have not done the belt on this car before is it the same as my other cars where you just get a wronce on the tensioner and twist it to remove pressure on the belt and simply replace the belt?


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## vtecgreen (Dec 26, 2010)

Did this a few years ago on my old B6 - Took me about 2 hours (only because it was hard to work under the car/get the sensor in - but saved untold amounts of money as opposed to getting it fixed at the dealer. 

Good luck!


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## cw2899 (Apr 13, 2011)

*CPS replaced!!!*

Ok, I have to say anyone with a bit of patience and mechanical dexterity can make this repair. In fact the serpentive belt took longer to replace because of it's confined space. I replaced my CPS this weekend and it took about 2 hours. I will say though it was easieer to get to it from on top of the engine in my opinion, but that's just my opinopn. The hardest part was cutting all the tie wraps along the cable bundle. But i could easily reach the sensor and bolt from on top and it took no time to replace. Just remember this is a fine thread bolt so it seems to take forever to get the bolt out. Just remember to erase the codes before starting the car. Bottom line, simple repair.


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## woofster (Dec 16, 2002)

Glad to have stumbled upon this thread after doing a forum search. I just started on replacing my crank position sensor this afternoon but decided to take a break when I realized just how difficult it was to get to that tiny little hex bolt!

I posted in a thread on AudiZine with photos as well: http://www.audizine.com/forum/showthread.php/431573-Crank-Sensor

I'm encouraged to hear that it is indeed possible to remove the sensor from above since there seems to be even less acess from below. Looking forward to giving it another go once I pick up the new part! :thumbup:


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## igortiger (Apr 24, 2011)

Anyone do this on a 3.0?


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## 98blueb5 (May 12, 2008)

yea, its pretty similar, but its def a PITA.. If you have big hands, its not gunna happen.. Also make sure your car isnt warm; i burnt my hand a few times on the exhaust while doing it...

Also, BE SURE to take the spacer off the old sensor and put it on the new one!!!! The first time, i didnt do that and when i started my car, i heard this grinding noise then my car shutoff.. The top 1/4 inch of the sensor was ground down... NOT FUN to have to replace that sensor twice!!!

I also would recommend not completely removing the old sensor from the car until you are for sure that the new one fixes your issue.. Having to do double the work to get nowhere is never fun!

Once you replace it, you should notice a difference immediately! Just gotta be patient with this one :thumbup:


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## igortiger (Apr 24, 2011)

98blueb5 said:


> yea, its pretty similar, but its def a PITA.. If you have big hands, its not gunna happen.. Also make sure your car isnt warm; i burnt my hand a few times on the exhaust while doing it...
> 
> Also, BE SURE to take the spacer off the old sensor and put it on the new one!!!! The first time, i didnt do that and when i started my car, i heard this grinding noise then my car shutoff.. The top 1/4 inch of the sensor was ground down... NOT FUN to have to replace that sensor twice!!!
> 
> ...


What symptoms did you experience with a bad sensor? And which code exactly came up on your ECU? 

BTW, thanks, it helps to know I may spend the entire day doing it if I need the sensor. 

Igor


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## 98blueb5 (May 12, 2008)

This was probably a year ago, dont even know if i bought VAG yet.. I dont remember the code i was getting but i knew that my car would start in the morning, but once i got off the highway and sit at a stop sign, it would die and not start again until the engine cooled down.. I would have to keep pulsating the throttle to keep it on.. So car was basically useless unless i planned on staying at one spot for a few hours... There may have been other things, but i remember this was the biggest problems i had with it.. Hope this helps!


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## igortiger (Apr 24, 2011)

98blueb5 said:


> This was probably a year ago, dont even know if i bought VAG yet.. I dont remember the code i was getting but i knew that my car would start in the morning, but once i got off the highway and sit at a stop sign, it would die and not start again until the engine cooled down.. I would have to keep pulsating the throttle to keep it on.. So car was basically useless unless i planned on staying at one spot for a few hours... There may have been other things, but i remember this was the biggest problems i had with it.. Hope this helps!


Did your car like sputter? I have a sputter issue after I get on the gas hard. When I clear the MIL it seems to go away. Was it progressive, did it start small and get worse or did it just start? 

Igor


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## hilltim1 (Jul 24, 2012)

ocod2020 said:


> hope this helps
> 
> http://www.a4mods.com/index.php?page=webcontent/pages/enginespeedsensor.html
> 
> the problem will get worse and leave you stranded if you don't replace it


Why do people keep linking this when refering to the Crankshaft Position Sensor and the guide says it's for the Speed Sensor.. I want to assume they're not the same thing, are they?


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## sinistervii (Jul 14, 2011)

Engine speed sensor and CPS (crank position sensor) are the same thing. I was confused also at first when mine failed. The CPS or ( speed sensor ) read the speed of the flywheel revaluation, which determines the speed of the crankshaft, which tells the ECU some B.S. for some other B.S. to do...... mainly with everything that keeps your motor in working order. If this fails, you go into LIMP mode.... no boost, no power ect..... Blah Blah..... always fix anything on these cars. thats what ive learned. do not ignore


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## gtsingh91 (Mar 13, 2008)

I hate to revive an old thread but instead of making a new one I will comment here. My car (05 B6 1.8T quattro) died yesterday while I was driving on a side street and would start back up for a second and then stall again. I'm not sure if its the CPS or if it's a fuel pump issue.


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## vwchivette (Nov 13, 2008)

I also unfortunately am having the same problem.

However, I replaced the crank position sensor and still no start. Everything checks out okay otherwise. The only code is the P0321. Any suggestions?


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## gregg3gs (May 15, 2004)

vwchivette said:


> I also unfortunately am having the same problem.
> 
> However, I replaced the crank position sensor and still no start. Everything checks out okay otherwise. The only code is the P0321. Any suggestions?


have you erased error code in the ecm?

once some error codes go into ecm, the engine will not start back up until they are erased.



Also,


> which tells the ECU some B.S. for some other B.S. to do......


 is my favorite new quote. :laugh:


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## vwchivette (Nov 13, 2008)

gregg3gs said:


> have you erased error code in the ecm?
> 
> once some error codes go into ecm, the engine will not start back up until they are erased.



Code was cleared, still no start. Guess this thing wants to play hide and seek the problem like usual.


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## gregg3gs (May 15, 2004)

vwchivette said:


> Code was cleared, still no start. Guess this thing wants to play hide and seek the problem like usual.


 hmmm, 

do this: 
- disconnect maf sensor connector 
- disconnect ob2 primary sensor connector 

start the car 
-does it run? 

Yes you will have to clear more codes after this but maybe the throttle body is getting a wrong reading.


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