i have replaced the timing sensor twice, along with the cam gear (because i bent the timing part of it) and still am getting the error code 16725.
wtf is wrong with my 2.0? other than being a 2.0
The cam. pos. sensor is a hall effect.
-verify voltage and ground at connector (refer to schematic for wire configuration) with volt meter.
-verifiy square wave / signal at same connector with a graphing meter (or a homemade 5volt led test light) DO Not use a conventional test light
If power or signal problems are present, check at ECM side for open wire or ECM problem.
Quote, originally posted by silentsee4 » what is this square wave thing your talking about?
Quote » A square wave is a kind of non-sinusoidal waveform, most typically encountered in electronics and signal processing. An ideal square wave alternates regularly and instantaneously between two levels.
You usually use an oscilloscope to measure the performance of the sensor. I believe that the output should swing between gnd and nearly 5v.
- Bruce -
ok, and then from left to right in this picture of the plug which of the 3 holes is which?
and to do these two tests that are there for me to perform, which of these holes do i test?
thanks for your help guys, and gals. this all started as a simple cam install for me, and then snowballed into this huge and stupid CEL problem.
so i tested all of the female connectors and these are the numbers that i got. since i dont know which is which i simply tested all with a voltmeter
for these little diagrams the parenthesis represents the curved side of the connector, uppercase O's are the tested ports and lowercase o's are the ones left alone.
i really don't know what I'm doing so bare with me please
If you can probe the middle wire while the connector is connected you're looking for a square wave output. If you have a multimeter you can check the middle pin for DC to ground but the meter probably won't react quickly enough to give an accurate readout so just look for it to change states rapidly. If not look for positive DC on the + pin and ground on the - pin. Troubleshoot from there. I'm not sure but I wonder if you can pull the sensor, turn the key on, and then monitor the center pin. All you have to do then is swipe a magnet over the sensor and see if it changes states. Just a thought.
Modified by mcoomer at 4:48 AM 2-24-2009
What were the running problems with the 2.0l with DTC 16275 camshaft position sensor
range/performance? I know that the CEL is on but does the car show any seroius
functional problems? Also, what was the fix for your car?
I fixed almost all the problems with a new throttle body and a good used air flow sensor.
However, DTC 16725 remains and interestingly throttle body adaptation ran to OK on this 2.0l
99.5 Jetta with an AEG code engine. My local VW dealer tech said he has seen no starts
with 16725 but this Jetta starts well and only has a poor throttle response to more than a quarter throttle opening. This Jetta will reach and maintain freeway speeds if accelerated gradually.
With 183,000 miles on the odometer I am thinking the catalytic converter is partially plugged. Has anyone else had a similar experience with a 16725 DTC on an AEG 2.0l engine?
From my experiences with 16725 on that style Cam. position sensor:
-Bent / damaged pick-up on camshaft sprocket. (a result of tampering or forcing it)
-Incorrect valve (mechanical) timing. This includes damage to the cam. at the key way location and the actual belt timing possibly off a tooth or so.
I have never seen a faulty ECM cause this, but it is possible.
Also see the link Bruce found http://en.wikipedia.org/wiki/Square_wave
Do you have a graphing meter or oscilloscope? This will be necessary to see the actual signal from the CPS.
Yes it can cause a drive-ablity problem due to being in a fixed timing map.
Verify your timing is correct.
As what Dana said above is right on . Also check the key-way on the crank to key-way on cam for damage. If your marks line up.
It is most likely that something is out of correlation but could also be a sensor, reluctor air cap incorrect, or damaged harness issue or bad ECU.
Do you know which display group the 99.5 AEG code 2.0l Jetta uses for ignition timing mapped values? The one VW factory manual I have for an AEG 2.0l does not include a procedure for checking ignition timing control. For AAA 2.8l VR6 engines display group 10 shows the mapped ignition timing values but I don't know if the AEG 2.0l uses the same group. Also it was curious that throttle body adaptation ran to OK with the 16725 DTC always present. I thought that all DTCs had to be corrected and cleared before the adaptation of the throttle would run correctly.
No the ADP can fail on some cars and even pass readiness monitors.
16725 code has nothing to do with the ADP of TB.
The information for timing is in the factory repair manual for AAA and AEG
Also Vag-Com labels the channel and displays a spec in the balloon so you don't have to go hunting through the repair information.
My question on mapped ignition values for the AEG 2.0l is exactly because that data is not included in the factory repair manual W42 008 198 103 Edition 01.98 that I have. The mapped values are included in the 2.8l VR6 repair manual for the AAA GTI/Golf/Jetta. VWs service manuals are far from complete and I am not describing the Bentley version but the expensive multi-volume sets issued by carline.
What your asking for is for a test that was originally for ABA and AAA engines which use 259 series Bosch ECU's for OBD2.
The old ECU's you did a test in 010 and then 045-046 for knock
Then Cabrio late had its own in 022-023 for knock and these Ecu's were a transition into the four body but also had a ABA and A3 chassis.
The ECU for an AEG is 018 and never supported this test. To my knowledge described as Ignition timing control checking being specific.
It supports the test in a different way combined with knock control.
01-04-028 test verify and further for vehicles 98> with some ECU's also having variable cam shaft control. example 094-096 tests for cam control. There are other channels for additional tests with bin bits.
You can always verify CF of each cylinder in Vag-Com to see whats going on.
Just because a specific test existed in a old car doesn't mean it will be used in a different fuel or ignition system.
The test does exist, just a different way.
Thanks for the explanation. Do you know if for the 99.5 Jetta 2.0l AEG engine if a 16725 DTC
can under certain conditions send the ECM and /or throttle control module into the emergency running mode? The owner of this 99.5 Jetta cannot afford to replace the camshaft position sensor and is driving the car with a 16725 DTC present at all times. Most of the time the Jetta runs and drives satisfactorily (actually drives pretty well for 183,000 miles Charity Motors car) but occasionally the Jetta will exhibit a severe driveability problem with no ability to develop any engine power. The DTCs at that time are throttle control module related even though there is a new throttle body with clean grounds and proper supply voltage. The problem is intermittent and cannot be reproduced with any degree if regularity--it just happens under very different conditions.
Hate to drop in on all of this heavy lingo, but I am having this problem on my vr6 and too am trying to reslove the issue.
The time i notice is most is on startup. It smells very rich. The car has trouble idling andgod forbid I press the accelerator! haha The rpm's will dip to 3-400.
Also from reading the posts it sounds like this seems to be more of a throttle body and ecm problem as opposed to a faulty sensor? I mean correct me if I'm wrong.
Quote, originally posted by Peter Badore » The owner has the 99.5 AEG 2.0l Jetta (aka Jetta from hell)
I have to agree, my 99.5 AEG jetta is also a jetta from hell. I had similar code ( 16705) and ended up replacing the sensor. The wiring to the sensor was frayed.
VCDS Diagnostic System For VW/AUDI/SEAT/Skoda/Bentley
Has anyone run a 99.5 Jetta or Golf AEG 2.0l engine with the camshaft position sensor disconnected? if so, what did it do? Our Charity Motors project 99.5 Jetta AEG 2.0l is now a no start. I knew I would see it again has soon as the towing company brings it back.
The Jetta's owner has limited funds and purchased the car from Charity Motors with a US Federal low income grant of $1800.00 (aka free money). All of which makes the comment "just fix the car" easier said than done--the owner has no money to buy any new parts. Because of this we sold the owner a new throttle body assembly at the shop's wholesale cost not retail. Unlike the US government we can't just ask the Department of Treasury just to print more money! However, we fixed the no start and the related driveability problems yesterday with used parts. I would still like to understand the VW emergency running mode parameters because I stalled the Jetta using VAG-COM to delete fault codes.
I'm having similar problems in my car. Replaced the entire distributor with camshaft position sensor inside it. it acts like its in default timing map because I can unplug various things like cam sensor on distributor or knock sensor and nothing changes. Observing OBDII timing advance readout in VAGCOM, at idle its around 12 degrees which is the same as my truck and many other vehicles. In the factory manual it states timing will be retarded I forget some degrees like 12 or something, so it should be zero at idol? But its not, so I don't know what's going on. I haven't yet checked mechanical timing from cam to crank but I will tonight. The belt is tight and new I changed recently, and it was running great. I'm throwing a P0341 Camshaft implausible code. I have factory manual which says more specifically that means the signal coming from the camshaft position sensor doesn't make sense. I know for a fact, previously, if I unplugged the sensor while the car was running it stumbeled and (I assume) went into a default timing map or fuel injection timing map of some sort.
What's amazing about this car, I can rotate the distributor 90 degrees or so, and it will still run. how does the computer know when to fire the cylinders? It must do some fancy testing or knock testing or timing manipulation very quickly to determine i'm turning it. Keep in mind this is with the cam feeback unplugged.
I tested it with a LED and it works perfectly, and ohmed out all wires. I've done all the simple tests (except mechanical) that I can think of.
Anyone know of a way in vag com to more deeper check the timing? See if the car is running default map or receiving correction from the cam position?
I also unplugged knock without any response from the engine, where as I said above manual states it should retard timing severely. But is that default timing map or is it responsive timing with feedback, just retarded 12 degrees?
AHHhhh I wish I knew the algorithm it uses to go into default. Or what some of those many timing fields mean in the engine block inside VAGCOM. I have messed with this thing obsessively and can't figure it out.
Called a specialist in houston who has seen this a lot and he said replace ignition coil, lol. So I'm gonna try that tonight too; I suppose a weak spark could produce knocking or some strange thing the computer somehow detects and throws it into weird default mode.
What about more specific VAGCOM group tests? They aren't in my factory huge bentley manual. They were available to the online version you could used to rent access to through Bentley publishers website but that's not anymore; and I thought it was just in the factory manual but its not, only a couple things like throttle adaption. I know stuff like forcin the EVAP test, i printed out years ago, and still have, but its NOT in the factory manual! Frustrating!
If I knew a more sneaky timing group test or knew what some of those fields meant it might help.
I thought maybe also the MAF sensor could be causing issues since I can unplug it with no response at all from the engine. I still think its in some sort of default timing/fuel map since sensors don't seem to change anything. only code being thrown though is this P0341.AHHHH
Any help would be greatly appreciated, thanks!
Pull the dist. cap and the gray/black cover under the rotor. Make sure the center of the rotor is directly over the mark on distributor housing at TDC.
I would verify TDC at the Cam,Crank/Dampener and directly at the flywheel. Note the "V" on the flywheel is not TDC, there should be a -0- mark.
Update with your timing belt status and the above mentioned checks.