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Hi Everyone, just wondering if this was ever resolved. I've read through probably all of the VANOS related thread and cannot seem to find a resolution for my car. I'm getting similar symptoms for code 72. Swaped boards, resoldered all joints, replaced diodes, replace solenoid rings, beisan rings, cleaned all ports on the VANOS unit itself, and installed new CPS (all 4). I'm still reading error 72. One thing I still have not done is swap the VANOS units. Just wondering if there is anything else I should check. Thanks. This is driving me crazy.
 

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They have all been resolved but most are different. You no results or any change from doing the things you have done? It is a bad ground then. In the electric conduit right over the fuel rails is where the grounds for the vanos solenoids join, check that.
 

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Thanks, Sailor. I just read that from another post last night. I will check that when I fine the time and report back. That sounds like it could be the issue. Yes, no results from everything I've done so far.
 

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I finally had time to check the ground leads on Bank 2. Looks like there's some corrosion which I'm currently soaking in vinegar. I check the resistance on all the pins and they seem kind of odd.

Bank 2(key off):
Pin 1 is 3.8koms
Pins 2 and 5 are both reading about .8kohms,
Pin 4 is 8.5kohms and 6 is 8.6
Pin 3 is 216.9kohms??

Bank 1(key off):
Pins 2 and 5 are .5kohms
Pins 1, 3, 4, and 6 are all around 8.5

Would a bad ground cause the high resistance reading for B2/Pin 3? I checked the voltage with key on and B2/Pin 3 shows 70mV and Pin 1 58.1mV. comparing with B1, readings show 1.1mV.
 

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I traced the high resistance reading from pin 3 all the way to the DME. The high resistance reading isn't from the wiring, I think it is coming from something inside the DME box. Checked resistance from where the Pin 3 wire connects to DME (DME side) tground is the high resistance reading comes from there. Should I open up the DME and take a look or is this a sign I need to replace it? Now I'm worried.
 

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EDIT For some reason I did not see all the other pages on this thread. I will read those first. Anyone who cares to read the dissertation below, thanks in advance!



Guys I have a question which I think is related to this and I figured better to post here than to start a new thread. I'll give you the codes i'm getting and then some back story.

72 Exhaust camshaft VANOS position control, Cyl #5-8
C7 Misfire, Cyl #4
B9 Exhaust camshaft VANOS position control, CYL #1-4

This is an '01 with now 154k miles on it. I bought it just shy of two years ago at 123k. Maybe the best two years of my life so far! :)

In October of last year, I had a slew of seal/valve failures. Crankcase breather valves, oil input regulators, and none other than a full Vanos system re-seal. It should follow from this that I had a fairly reputable guy all over my Vanos seals and boards and after this costly adventure should expect things on that end to be ok. I believe this was the second big vanos re-seal in the life of the car.

Side note: for a very long time I have had an E-Box fan code thrown from time to time, never really looked into it and the tech that did my Vanos said to keep an eye on it but that it shouldn't make anything drastic happen, but that it was responsible for cooling the DME. I live in Atlanta and it gets hot out here in the summer...

Further side note, I put in an aftermarket android head unit shortly after the Vanos adventure and have had a heck of a time with poor grounding and noise in my speakers. Most puzzling is that it is intermittent, seeming to be better or worse sometimes when I restart the car. I unplugged the head unit several times to see if it changed how things ran, but the intermittent roughness continued.

Throughout November I started noticing a roughness in the exhaust. At first I thought it was just the temperatures dipping for the first time, but it was strange because cold starts had never been that rough the previous winter. As these things go, I've also had front brake warping problems, and my tech advised me to try to re-bed the brakes. One morning I was doing that on a quiet stretch of road. The second stop I made suddenly sent my car into what I assume is limp mode. Very ugly uneven idle, check engine light on, low rev power basically gone. I limped to a parking lot. Restarted the car and all it went away. I had seen a ghost and had no evidence to prove it.

After that the intermittent exhaust roughness continued, however with no other drastic performance consequences, except maybe one or two less miles per gallon (but I was willing to blame my right foot for that instead). Sometimes it would run perfect with no odd sounds at all. No concrete correlation with outside temperature.

Last night the check engine light came on and seems to be staying on. Exhaust is back to full bronchitis. The codes above are what I pulled. I jumped to some conclusions that I need to replace the CPS and was about to pull the trigger on all four, 2x intake and exhaust. But then I remembered the code said VANOS and I remembered some vague comments my tech made about a DME and the weird apparent ground issues.

Is there an explanation to link all these things?

Pardon the short novel on all of this, but I am not sure where exactly to look next and I don't feel like shoveling out a bunch of cash to my local shop to do the sleuthing. Barring more direct advice, I plan on looking up where exactly the DME is located and seeing if I can find any connection problems. And look up how to do that.... I am also happy to replace the CPS's, but also would like to know if that is indeed going to be the root of the issue.
 

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Jumped the gun... Took a look inside the DME box and found a fried chip(BTS621L1). I guess I'll order one and have someone at work solder it in. I guess we'll see what happens.

I am a couple of steps behind you on this, having not yet studied my DME. But what happened? Did you find a replacement for the fried chip? Did you get it soldered in and did that work?
 

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That post was 6 months ago. The DME is the least likely cause for your issue. The CPS sensors are the first step. There is an old style that is known to fail. If yours have not been replaced that is where you start. If they have been replaced, your VANOS solenoids are the next most likely culprit, regardless of the fact they have been worked on. Getting the solenoids cleaned out is tricky and sometimes impossible, requiring replacement of individual solenoids.
You should review the sticky thread on it:
 

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So I got the B9 code a couple of weeks ago. The car sounded like it had an exhaust leak at idle and was down on power.

I swapped exhaust CPSes side to side with no change. I pulled both boards, did the cleaning procedure, verified solenoid functionality, and put everything back together with new o-rings. It seemed all right until today. I got on the highway and the car lost power. Code B9 again. Low exhaust note and a rough idle now. It sounds like it's cammed and also has the hot idle tick. Worse than before.

I pulled the bank 1 board just now and noticed that my new gasket was wet on one corner. Somehow oil is seeping past the o-rings on one solenoid. This is the offending solenoid bore:

949590


I retested the board and all of the solenoids click well. I'm going to swap boards side to side to see if the problem moves, but is this more likely a clogged passage, hydraulic, or mechanical issue?
 

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is this more likely a clogged passage, hydraulic, or mechanical issue?
Could be anything still. Lots of people have had to do the job a couple of times. Sometimes it is some crud that would not clear because it was packed in, but the cleaning loosens it up and then while running it comes free. Sometimes it is a bad diode or bad connection that just removing the boards reconnects. The solenoids will click if the diode has failed. Did you resolder things when you had them out? Did you use a compressor and blast them with max air pressure or just use a can of cleaner on them? Not using a compressor to clean them often means you have to do the job twice. You need to test the diodes by de soldering the solenoids and testing for continuity both ways.If they are working power goes one way but not the other.
I don't know what that is but it need to be looked at.
949591
 

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Could be anything still. Lots of people have had to do the job a couple of times. Sometimes it is some crud that would not clear because it was packed in, but the cleaning loosens it up and then while running it comes free. Sometimes it is a bad diode or bad connection that just removing the boards reconnects. The solenoids will click if the diode has failed. Did you resolder things when you had them out? Did you use a compressor and blast them with max air pressure or just use a can of cleaner on them? Not using a compressor to clean them often means you have to do the job twice. You need to test the diodes by de soldering the solenoids and testing for continuity both ways.If they are working power goes one way but not the other.
I don't know what that is but it need to be looked at.
View attachment 949591
  • I did not resolder anything while I had them out. I was taking a minimally invasive approach.
  • I only used a can of MAF cleaner to blast them; no air. What pressure do you recommend? As high as my compressor goes? Also, do you blow them out both ways or only through the inlet?
  • That crud is caked oil/dirt. When I pulled the covers the first time, it was evident someone had already been in there. There were vice clamp marks on the noids and the gauze filters were already removed. No idea when it was done, but I'm at 70,000 miles now.

Swapping the boards side to side yielded code 71, Intake camshaft 2 VANOS position control, so this is a noid problem. Looks like I'll be cleaning them again, along with resoldering and continuity checks.

Thanks!

Chris
 

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What pressure do you recommend? As high as my compressor goes?
Pretty much, unless you have an exceptional compressor, 125, 150 PSI. The oil pressure is 1500 so you will not hurt it but you can also see that with the lower pressure you will likely have to blow air different to the normal flow that packed it in. Yours sounds like an electric issue, but a full electric failure has another code.
You just have to do it all to cover the bases. They have to click but also need to sound the same, which is a bit subjective. Follow the BTSmitty thread and you should be fine.
 

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Are you powering the noids on when you are cleaning them? This is a must. You need three or four hands or get creative. I rigged up a switch using a doorbell I activate with my foot while I spray brake cleaner through the side hole. You should get a geyser shooting straight up from all four noids. If one sprays weaker or kind of sideways keep cleaning.
Shoot compressed air through the top hole while activated of course. If you can't get it clear you should replace the noid. I have had to replace one or two over the years to get rid of my codes.
 

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Are you powering the noids on when you are cleaning them? This is a must. You need three or four hands or get creative. I rigged up a switch using a doorbell I activate with my foot while I spray brake cleaner through the side hole. You should get a geyser shooting straight up from all four noids. If one sprays weaker or kind of sideways keep cleaning.
Shoot compressed air through the top hole while activated of course. If you can't get it clear you should replace the noid. I have had to replace one or two over the years to get rid of my codes.
Yep, I had the noids powered while cleaning them. Blew MAF cleaner and compressed air through them. Also desoldered all of them to check the MOVs, which were all good. Sucked off all of the old solder and reflowed all the joints. So far so good!
 
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