The cam position sensor is critical to the proper functioning of the engine management system in its timing of engine events. The sensor delivers information on the position of the camshaft that actuates the engine’s intake valves to the computer, which uses that information to deliver fuel and spark at the correct time.
As you can imagine, if the air/fuel mixture in each cylinder doesn’t get lit off by the spark plug at the correct moment, the engine just won’t run right. Like all modern engines, the 1.8T relies on a host of sensors like this to operate. On the one hand, it means you can no longer tune your engine with a screwdriver. On the other, these kinds of sensors provide very accurate and robust information to the engine, allowing modern computerized engines to operate much more efficiently than older engines with improved driving characteristics and power output. In essence, computerized engine management made turbocharged engines like our 1.8T much more viable for auto manufacturers to build and sell.
Fortunately for us, the cam position sensor in the 1.8T sensor is conveniently located and fairly easy to change. In the photos below I have moved the radiator support panel into the service position, but I don’t think it’s necessary to do so.
First, remove the upper timing belt cover at the front of the engine. Simply release the two clips holding it in place. Ignore the fact that the wiring to the cam position sensor is already disconnected in this photo. Below I’ll show you what it looks like and how to disconnect it.
This is the metal clip on the other side of the cover. You’ll also need to move the two hoses that run across the face of the cover. You can simply slip them out of their supporting clips and pull the cover upward to remove it.
With the sensor removed, note the green-grey metal piece that remains attached to the cylinder head. Also note the gaps in the piece that alternate with portions of the cup-shaped “wheel” that remain, forming a set of “teeth”. As this metal wheel spins along with the intake camshaft, the teeth pass through a gap in the functional part of the sensor. Depending on whether that gap is blocked by the metal teeth or not, the sensor alters the voltage signal that it sends to the engine computer, which interprets the voltage to determine the position of the camshaft.
The trickiest part of this job is reinstalling the timing belt cover, particularly where it interlocks with the lower timing belt cover. Get the covers locked together correctly first and then you can snap the top back onto the top of the valve cover. Last, reconnect the wiring to the sensor and replace the vacuum and coolant lines that run across the upper timing belt cover.
Comments: 2003 Audi a4 1.8t random misfire when the engine starts then goes away but engine work rough, and i failed for OBD not readiness any help it would be very apreciated!!!
April 16, 2014
Comments: Audi a4 1.8t random misfire when the engine starts then goes away but engine work rough, and i failed for OBD not readiness any help it would be very apreciated!!!
April 16, 2014
Comments: I have an Audi A4 Quattro and the engine generally runs fine cold and also when reaches the optimal running temperature. After driving a while I park the car then start the car back up after a few minutes and the car runs rough for a while then after a bit it goes back to running normal again.
What are your thoughts? Is it the Camshaft Position
April 7, 2014
Followup from the Pelican Staff: Not sure, is there a fault code for the camshaft sensor. I would check the engine for a misfire when it is running rough. Isolate the cylinder, then check spark, fuel and compression on that cylinder. - Nick at Pelican Parts
Comments: i have a 01 gti 1.8 aww engine. i changed the cam position sensor and now it cranks but doesnt start the first 2 times trying but will start the third time, sometimes the second. It did not do this before, replaced it because it was throwing a code for the cam position sensor. any thoughts??
March 23, 2014
Followup from the Pelican Staff: Is the fault code still present? Or a new one stored? I can't help without knowing what is missing from the system when you are trying to start it. When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and pressure fuel, volume and quality. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.
- Nick at Pelican Parts
Comments: Thanks for your help. Come to findout the rear tensioner for the advancement on the intake side had broke. The lower guide had snapped causing more slack in the chain and allowing the intake valves to smack the pistons. The first piston it completely broke from one valve to the other.
March 22, 2014
Followup from the Pelican Staff: Thanks for the follow up. We appreciate it. - Nick at Pelican Parts
Comments: Well i havent comfirmed the timing has jumped at all but the belt is still in good condition from what i can see and was changed about 40,000 miles ago i was told by the previous owner. When i hooked the scan tool up to it it said something about the cam retardation not in its value. I was hoping it was just a sensor but im believing it is bent valves. On another note. I can get another passat that has been wrecked but its a 2000 with a 2.0 and 5speed and im debating if it would be worth while to swap motor and comp. Is the 2.0 the same bolt pattern as the 1.8? Thanks for your help.
March 16, 2014
Followup from the Pelican Staff: The 1.8 and 2.0 are different. The cam angle code was referring the jumped belt. I would reset the timing and check engine compression. It might be OK. - Nick at Pelican Parts
Comments: My motor has 250,xxx on it and was wondering if there is anything that would make it stop running out of the blue.. its a 2002 vw passat with the 1.8t and it detected random mutipule misfires and the cam retardation was out of value. When it cranks it almost sounds like it has no compression... Any clues?
March 6, 2014
Followup from the Pelican Staff: The timing belt may have failed. That would cause engine damage and a no start. - Nick at Pelican Parts
Comments: My engine runs great but still have the p1340 code. Change the crank position sensor last year. Could the cam sensor be the culprit.
March 2, 2014
Followup from the Pelican Staff: The cam sensor could be the issue. It could also be engine timing. - Nick at Pelican Parts
Comments: The error code is p001 camshaft position censor
February 28, 2014
Followup from the Pelican Staff: Your code is missing a digit. Should be one letter followed by 4 numbers. - Nick at Pelican Parts
Comments: Hi...question i have a 01 Volkswagen passat 1.8t it keeps giving me a camshaft position sensor code I have changed the sensor twice and also the cam chain tensioner and check the timingwhich is right and the code came back on after I did all that and it's running rough any ideas what it could be?
February 27, 2014
Followup from the Pelican Staff: If the sensor has been replaced and engine timing is correct, not much else can cause a cam sensor code. However, you did not mention the code number, so I am shooting in the dark. - Nick at Pelican Parts
Comments: ive got a 2002 volkswagen jetta 2.0l 4cyl 5 speed manual . is it the same process to change the camshaft position sensor as shown above?
February 15, 2014
Followup from the Pelican Staff: No, this tech article applies to:
Audi A4 (1997-02)
Audi TT (2000-04)
VW Passat (1996-00)
VW Golf (2000-02)
VW Jetta (2000-02)
VW Beetle (1999-02) - Nick at Pelican Parts
Comments: My 02 vw jetta is throwing a code the states a CPS. I have looked at a few forums and some are saying I should use "sea foam" and flush everything out before getting into the sensor... What should I do. On a budget
February 11, 2014
Followup from the Pelican Staff: What fault code? If it is a sensor code, I am not sure how cleaning the engine would remedy it. - Nick at Pelican Parts
Comments: Strange no start condition. Have fuel,air,spark. Injecting ether into a cylinder does little. It started after removing the TB cover. Suspect CPS. Harness test shows 5v on pins 1&3. Codes from Vag com clearned so little new info to work with. Code 16396 - Bank 1: Camshaft A IntakeP0012 - 35-10 - Advance Setpoint not Reached Over-Retarded - Intermittent was pulled prior to clearing codes. Any thoughts? Mine are it has to be injecting at the wrong time.
January 18, 2014
Followup from the Pelican Staff: I would check compression and mechanical engine timing. Sounds like it may be off. - Nick at Pelican Parts
Comments: Hi All. Wheres the crank sensor located on vw golf turbo 2001 'Y'
January 10, 2014
Followup from the Pelican Staff: At the front of the engine, next to the oil filter near the transmission bell housing.- Nick at Pelican Parts
Comments: Coolant temp sensor that would be the thermostat right?
But is that relevant to the crankshaft position sensor being faulty/ becoming faulty? could let's say its about the fuel injector leak or whichever of the ones you stated, so could a faulty "x" cause the crank sensor to stop working and not sending current to the coils or some sort of effect like that? Thank you for your support and I kinda figured it would be most useful to post questions here just wanted your opinion about it. Thanks again and no my problem is still not solved I don't have a lift in my driveway to lift the car and change the sensor so I'ma have to take it to garage I think : less experience for me but... I need my car :s lol Aight Thanks brother have nice holiday season ;
December 22, 2013
Followup from the Pelican Staff: We cannot really get into what could be wrong without some data. At this point, it is a dice roll.
The coolant temp sensor is a sensor that measures engine coolant temp. It is not the thermostat. Neither could cause the crankshaft to stop working. - Nick at Pelican Parts
Comments: Agreed Nick that goes pretty much without saying...
Problem Is all that was fine up until the engine "flooded" I "know" this because we managed to get it to start 2-3 times removing one plug and firing up the engine to blow out/burn the excess of gas before it stopped firing up for good....its only after that that I got myself a scanner and pulled the codes... Now I know this isn't some "fix my car for me please" forum and I would be extremely grateful if there was a way we could talk about this Nick. if you'd rather me keep posting on this page as it may/may not affect other people as well, just let me know
email@example.com : thanks for quick reply will recommend pelicanparts to all my ppl Thx again : Have a nice day!
December 9, 2013
Followup from the Pelican Staff: If the engine is flooding, you could have an issue with the coolant temp sensor, too high of fuel pressure, or leaking fuel injectors.
Posting here is the best way, then others benefit from the discussion. - Nick at Pelican Parts
Comments: "In the photos below I have moved the radiator support panel into the service position, but I don’t think it’s necessary to do so."
It isn't.... so long as you dont lose a bolt in the timing chain path then you have to do it to go GET the ****** bolt.... other than that I have managed to change the sensor no problem I just cannot start the engine for sh*t now.... but I don't know if it is even related since I changed it because the car wouldnt start in the beginning soo.... as you may guess I'm a little screwd... :S
December 8, 2013
Followup from the Pelican Staff: You need to know that the basics--compression, fuel supply, spark are (or are not) correct before worrying about the camshaft sensor. - Nick at Pelican Parts
Comments: Many thanks. I know it's a simple job but it's nice to see how it's done, especially when you're doing it outside in November. Why is it that these things always happen when it's either dark, cold or raining ?!
November 25, 2013
Followup from the Pelican Staff: That is the way it works I guess, the challenges stack up. Thanks for the feedback. Glad we could help.
- Nick at Pelican Parts
Comments: Does this process apply to the 3.0L V-6 in the Avant?
November 4, 2013
Followup from the Pelican Staff: No, this tech article applies to 1.8 liter engines. - Nick at Pelican Parts
Comments: very useful, thanking you heartily
September 11, 2013
Followup from the Pelican Staff: Thanks for the feedback. Glad we could help. - Nick at Pelican Parts
Comments: Is it about the same price to replace the cam sensor in a 2000 v w Passat?
September 3, 2013
Followup from the Pelican Staff: If you have the 1.8l engine, yes. - Nick at Pelican Parts
Comments: Can someone help me please? I cant get the camshaft sensor all the way in. There are pieces of metal flanged around that prevents it from alignin gto the bolt holes.
Please help me.
November 9, 2012
Followup from the Pelican Staff: Is the metal a heat shield? You may have to loosen the other fastenrs securing the heat shield to the engine, then install the camshaft sensor. - Nick at Pelican Parts
Check out some other sample projects from the book: