Cam Position Sensor code wont clear. Wont start. New motor. going crazy

[walky_talky20]

If they are relatively new, there should be no trouble reusing them. They are still squishy.

[victimdumper]

as long as the gaskets are still pretty new (i'm assuming they were put in when the new engine was put in) that should be fine for more than just temporarily

edit: didn't see walky's post

[iamshayan]

I'm not very good at counting but i seem to count 17 between each sprocket.

:/



matt devo helped me find the pins to check on the ecu connector.

for
cam position sensor its
Sensor plug pin # - Ecu harness pin #
1 - 98
2 - 86
3 - ground

for vvt tensioner its
1- ground
2- 115

how do I find out which pin is which and how do i open this connector / do I need to
can I stick a piece of wire in the hole?

[Seerlah]

Line up the cams first. There is a little notch that would sit in front of the arrow on the cam caps. Use those for reference points. You see my notches are right to the left of each arrow, but this was the closest I could get it when I checked mine with the front end still fully on (had to get the starter to turn for a split second each time to get it this close, and settled on it). You can simply rotate the crank bolt to get them to line up.

[Bische]

You have to have the engine at 0

[iamshayan]

You have to have the engine at 0

not anymore, I'll rotate it. Hold on.

[iamshayan]

zero'd it out.
can count 16 now.


devo helped me find this pinout of the ecu since there are no printed numbers
http://wiki.obdtuning.com/images/a/ac/VAG_ME7.x.jpg
then I found this link of how to remove the ecu. Seems pretty intensive.....
http://www.goapr.com/support/ecu_a4_b6.pdf

[Seerlah]

So much easier to take mine out on the B5. Haha

But once you get the connector off (be sure to remove the negative then positive cable before unplugging the ECU. In that order) you. An get the terminals off with unfolded paper clips. I'll take pics in a little bit to demonstrate. You can confirm you are dealing with the correct terminal by doing a continuity test. The probe won't fit in there, but you can stick a paper clip in there and test off that.

[iamshayan]

So much easier to take mine out on the B5. Haha

But once you get the connector off (be sure to remove the negative then positive cable before unplugging the ECU. In that order) you. An get the terminals off with unfolded paper clips. I'll take pics in a little bit to demonstrate. You can confirm you are dealing with the correct terminal by doing a continuity test. The probe won't fit in there, but you can stick a paper clip in there and test off that.

got it out. checking now.

[Seerlah]

I am using my AWM harness for reference, but I would not imagine it differs much from yours. On my harness the cam sensor has 3 wires, and they all go to the smaller connector that plugs into the ECU. If the colors of your wires match mine (just pull the boot back on the cam sensor connector to confirm), I would assume they go to the same terminals.

All on the smaller connector (confirmed with continuity test):
Black: terminal 108 (white connector)
White with black stripe: terminal 98 (white connector)
Green with grey stripe: terminal 86 (black connector)

I'll show pics of what I mean by the black and white connector once I upload the pics (next post)

[Seerlah]

Not quite sure what you are trying to do, but here is how you can get to the wires.

first pop off the little back cover





Then you slide out the pink retaining clips. The bigger one has little tabs locking it in place, but they are weak and you can just pull it out without pressing in the side tabs first. The smaller one is more tricky. You need to press down in the open slot (where the unfolded paper clip is) to release the locking tab to be able to pull the smaller retaining clip out. Hope you understand.



Once the retaining clips are out, you can now pull out the 2 little terminal bars or whatever they are called. On there, there will be numbers on each end of the terminal bars (or whatever they are called) This lets you know the number slot you are working with. You should see them. There are 2 terminal bar thingies...a white one and a black one. That is what I meant by white or black connector above in parenthesis.



As for removing an actual terminal, you should be able to see how they are locked in place if you ever played with removing terminals before. Get something really thin, like a razor, in there and release the locking tab on the spade to be able to just pull the terminal out.

Never opened up my ECU, so you are on your own there

[iamshayan]

okay, got it apart and tested resistance.
It starts at 1.5 and then drops down to about .7 and .8

[Seerlah]

I think you need someone like walky_talky20, old guy, or diagnosticator to help you from here. But out of curiosity, do our wires match on the AMB and AWM (same color and terminal designation)?

Also when you want to hook the battery back up with the ECU already plugged in, place on the positive cable first then the negative. In that order. This decreases the chance of you frying your ECU. Hence, why I said to disconnect it the way I did earlier.

[iamshayan]

So I buttoned her back up and took her to the show on sunday. I noticed It was revving really high at cruise on the highway, talked to a few people at the show who have done many builds on these 1.8's and they said that their pretty sure Its my cam chain tensioner. We think its got to be advanced a tooth. Which makes sense because I did count 17 from end to end. So I picked up a vcg and cct gasket and am going to swap my CCT from my old motor onto my new one (old motor had cct replaced less than 3months ago) will post results.

[Bische]

Called it

[walky_talky20]

The camshaft timing looks correct to me, but the pictures are crappy so it's hard to tell(no offense). You really need 3 total photos to be sure. Like this:

[AudiA4_20T]

So I buttoned her back up and took her to the show on sunday. I noticed It was revving really high at cruise on the highway, talked to a few people at the show who have done many builds on these 1.8's and they said that their pretty sure Its my cam chain tensioner. We think its got to be advanced a tooth. Which makes sense because I did count 17 from end to end. So I picked up a vcg and cct gasket and am going to swap my CCT from my old motor onto my new one (old motor had cct replaced less than 3months ago) will post results.

You checked the cams and the arrows lined up did they not?

[AudiA4_20T]

The camshaft timing looks correct to me, but the pictures are crappy so it's hard to tell(no offense). You really need 3 total photos to be sure. Like this:

looking at that one if he rotated a little bit more to line the left cam up the right one might be a tooth out.

[walky_talky20]

Clint, no matter which way you rotate it, the head in the photo set I posted is in time.

The arrow alignment on the intake cam is nearly meaningless due to the vast variability between the 2 cams without oil pressure in the tensioner. This is why good photos are necessary.

[travrach]

So OP what do you do to get it to start? In your 1st post you said it does not start...

[iamshayan]

sorry guys I have no time to deal with this today as I have a tone of work to do. I will update it when stuff actually gets done.

So OP what do you do to get it to start? In your 1st post you said it does not start...

see post 32-38

[diagnosticator]

In the case of a missing G40 signal, cranking duration has no bearing on whether it will start or not. Without the G40 signal, the ECU makes 1 guess per cranking attempt. It is either correct, or 180 degrees out. If the guess is wrong, holding the starter on longer will not produce a successful start (but may produce some backfiring). You must turn the key off and back on for it to guess again. You still have spark and fuel on every attempt, it just may be 180 degrees out of synch. In my experience (although not having scoped anything) the ECU seems to "guess" exactly the same every time. Whether the guess is correct or incorrect is entirely determined by the position of the camshaft at the moment the key is turned on.

The Bosch description for Cam Position Sensor failure, specifically with the ME 7.5 ECUs, is different than the earlier ME7 ECUs.

[diagnosticator]

okay, got it apart and tested resistance.
It starts at 1.5 and then drops down to about .7 and .8

That result is on one wire, right? What circuit, Cam sensor signal from the sensor to the ECU or +5 vdc sensor power supply from the ECU to the sensor? With the meter connected, move the wiring harness around, pull a little on the harness, between the sensor and the ECU. Does the resistance change when you pull and move the harness? Measure from either end of the Sensor signal return wire (testing from both ends is best) , to chassis ground, should be infinite high resistance, or open circuit. If there is a measured resistance between the sensor signal wire and chassis ground, of any value less than infinitely high Ohms, the senor signal return wire is shorted somewhere. Other than that, 1.5 Ohms end to end is to much resistance, and will cause an excessive voltage drop on the sensor signal value received by the ECU. Usually, it is not practical to expect to find the fault in the wiring harness. Instead, using the existing wire terminals, and a length of the original wire on each end, splice a new wire run outside of the harness between the sensor and the ECU, bypassing the faulty sensor wire inside the harness.

[iamshayan]

Thanks diagnosticator, the values I posted were consistent with both the wires that I tested. I tested them on both ends and wigled the wires around. They started off high and then dropped down to about .7, .6 where they sat stable- even when I wiggled them. I'm going to take a closer look at the cct now and if that doesnt fix my problem I will try running wires out side of the harness.

So I made some time today,
Pulled off the valve cover again. going to swap out the CCT with my new one (from my old motor). Just posting up those 3 pics that you guys asked for.


^ THIS ONE LOOKS OFF, NO?

[Seerlah]

I count 16 links.

[iamshayan]

[Matt Devo]

I count 16 links.

ditto

[Seerlah]

You still have 16 links. The CCT middle piston thingy is constantly in an up and down motion in accordance to the tension. If the middle piston mechanism of the CCT was in the upper position, then your notches would line up. Your timing is correct, as far as I can tell.

[Matt Devo]

n/m

[walky_talky20]

The Bosch description for Cam Position Sensor failure, specifically with the ME 7.5 ECUs, is different than the earlier ME7 ECUs.

Noted, and edited earlier post. Thank you for the correction, sir. I look forward to testing this out on a later ECU.

[Bische]

Worn chain maybe?

The oil residue on the cam lobes look somewhat erratic?

[AudiA4_20T]

so what happened? I don't think chain tensioner will fix this but who knows

[iamshayan]

To be honest, I didnt even replace it... I took this video today though
The idle is doing weird stuff. sorry for the long video, it may be hard to tell but ffwd through it if you have to.

[Seerlah]

Video is set to private.

[iamshayan]

Video is set to private.

fix'd gets 'good' at 50 seconds

[diagnosticator]

Thanks diagnosticator, the values I posted were consistent with both the wires that I tested. I tested them on both ends and wigled the wires around. They started off high and then dropped down to about .7, .6 where they sat stable- even when I wiggled them. I'm going to take a closer look at the cct now and if that doesnt fix my problem I will try running wires out side of the harness.

Analog volt/Ohm meter? Sounds like the instrument is not initially displaying the actual resistance value, so the 1.5 Ohms may not be relevant. I recommend obtaining an inexpensive Digital multimeter and performing the circuit resistance and continuity tests again. An analog meter cannot display short interval continuity glitches, like momentary open circuit or short to ground, when the harness is moved around and pulled on. A digital meter with a tone that sounds when continuity exists, will allow brief faults in the circuit to be more reliably detected. With a tone sounding when continuity in a test connection exists, any momentary loss of continuity will cause a likewise loss of tone sound-off when there is no continuity, from a break in the wire or a short connection to ground from a worn through wire insulation in the harness, A digital meter will also reveal circuit faults by changes in the display from the fast response of the display compared to an analog meter. Analog meters cannot display fast transient continuity or no continuity glitches because of the slow response and low resolution of the analog display. Analog meters are also subject to being inaccurate primarily because of parallax error when viewing the needle against the scale at an angle. Especially when using an Analog meter, remember to zero the instrument with the test leads touching each other, before performing any tests, to remove the test lead resistance from the displayed resistance shown.

[old guy]

Analog volt/Ohm meter? Sounds like the instrument is not initially displaying the actual resistance value, so the 1.5 Ohms may not be relevant. I recommend obtaining an inexpensive Digital multimeter and performing the circuit resistance and continuity tests again. An analog meter cannot display short interval continuity glitches, like momentary open circuit or short to ground, when the harness is moved around and pulled on.

A digital meter with a tone that sounds when continuity exists, will allow brief faults in the circuit to be more reliably detected. With a tone sounding when continuity in a test connection exists, any momentary loss of continuity will cause a likewise loss of tone sound-off when there is no continuity, from a break in the wire or a short connection to ground from a worn through wire insulation in the harness, A digital meter will also reveal circuit faults by changes in the display from the fast response of the display compared to an analog meter.

Analog meters cannot display fast transient continuity or no continuity glitches because of the slow response and low resolution of the analog display. Analog meters are also subject to being inaccurate primarily because of parallax error when viewing the needle against the scale at an angle. Especially when using an Analog meter, remember to zero the instrument with the test leads touching each other, before performing any tests, to remove the test lead resistance from the displayed resistance shown.

Excellent info as always

[iamshayan]

Analog volt/Ohm meter? Sounds like the instrument is not initially displaying the actual resistance value, so the 1.5 Ohms may not be relevant. I recommend obtaining an inexpensive Digital multimeter and performing the circuit resistance and continuity tests again. An analog meter cannot display short interval continuity glitches, like momentary open circuit or short to ground, when the harness is moved around and pulled on. A digital meter with a tone that sounds when continuity exists, will allow brief faults in the circuit to be more reliably detected. With a tone sounding when continuity in a test connection exists, any momentary loss of continuity will cause a likewise loss of tone sound-off when there is no continuity, from a break in the wire or a short connection to ground from a worn through wire insulation in the harness, A digital meter will also reveal circuit faults by changes in the display from the fast response of the display compared to an analog meter. Analog meters cannot display fast transient continuity or no continuity glitches because of the slow response and low resolution of the analog display. Analog meters are also subject to being inaccurate primarily because of parallax error when viewing the needle against the scale at an angle. Especially when using an Analog meter, remember to zero the instrument with the test leads touching each other, before performing any tests, to remove the test lead resistance from the displayed resistance shown.

okay so I pulled the entire harness.....

also borrowed on of these fancy old meters.

anyways I checked pins for cam position sensor its
(Sensor plug pin #) - (Ecu harness pin #)
1 - 98
2 - 86
3 - ground

I have consistent beeps and .7 .8 ohms of resistance beween plugs 1-98 and 2-86 but I believe I'm having grounding issues. It will not show any ground. I'm going to start digging into the harness now and will post back with results later.
cheers

[Seerlah]

Just a fair warning that there are a lot of wires in there. Have fun. Keep it neat

[walky_talky20]

Please explain how you are testing for ground, and why you think there is a problem.

The ground wire is another wire in the harness, just like the 2 signal wires you tested. You just check it end-to-end in the same way.