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That's a wild guess! Any way to diagnose Your idea?
easiest diagnose is just ECU replacement, it quite easy here: 2nd ECU renew by a tools then SCN coding or just authorize and activation with Star Diagnostic. For ME9.7, there are 02 version of ECU: ECU with 01 can bus (HW A002xxxx) and ECU with 02 can bus (HW A003xxxxx). ECU with 02 can bus is required for W221
easiest diagnose is just ECU replacement, it quite easy here: 2nd ECU renew by a tools then SCN coding or just authorize and activation with Star Diagnostic. For ME9.7, there are 02 version of ECU: ECU with 01 can bus (HW A002xxxx) and ECU with 02 can bus (HW A003xxxxx). ECU with 02 can bus is required for W221
Ok, I will send You my account number, please transfer 1500$ to do that "easiest diagnose".
I have finally managed to convert my shed into garage, and take of the front cover. And surprise- timing is correct! What does that means?
Post some pictures how everything is lined up. Also push the rail in as much as you can as if the tensioner was installed and post a picture of how far it goes in. Your marks could all line up but if you have excess slack in the chain it can cause the codes. Hooking up a four channel scope as I said in the past would tell you exactly how much deviation there is which could help but its already apart now so have to figure out by visual inspection. Remind me, would the codes return right away after clearing? Don't listen to the ECU comment. I have never in my life heard of the ECU causing these codes. I have had them fail to actuate the solenoids but that's it in regards to cam timing. When you initially changed the chain and gear did you change tensioner as well?
Tensioner is still in. I have just removed front cover, and one pulse wheel. (btw what is the size of torx on the other side of cam?)
Now, when I looked at it again, one mark seems one teeth off. Take a look at the pictures.
Yes, check engine was getting back immediately after erasing fault memory. At first while driving it was on and off for some time, but later it was constantly on. And sometimes I had long crank before start.
Originally Posted by knowbenz
Post some pictures how everything is lined up. Also push the rail in as much as you can as if the tensioner was installed and post a picture of how far it goes in. Your marks could all line up but if you have excess slack in the chain it can cause the codes. Hooking up a four channel scope as I said in the past would tell you exactly how much deviation there is which could help but its already apart now so have to figure out by visual inspection. Remind me, would the codes return right away after clearing? Don't listen to the ECU comment. I have never in my life heard of the ECU causing these codes. I have had them fail to actuate the solenoids but that's it in regards to cam timing. When you initially changed the chain and gear did you change tensioner as well?
easiest diagnose is just ECU replacement, it quite easy here: 2nd ECU renew by a tools then SCN coding or just authorize and activation with Star Diagnostic. For ME9.7, there are 02 version of ECU: ECU with 01 can bus (HW A002xxxx) and ECU with 02 can bus (HW A003xxxxx). ECU with 02 can bus is required for W221
Just to be clear "easiest diagnose is just ECU replacement" is NOT a diagnosis. Thats throwing parts at it in hopes that it will fix it. If you were to get codes 1200 and 1208 for right bank timing retarded every time you start the vehicle and the ECU was the fault the diagnosis would be simple. The cam position sensors produce a 5v signal that gets sent back to the ECU, if there were no signal getting back you would have different codes. Having timing retarded codes indicates there is a signal getting back to the ECU but at the wrong time. Excessive resistance within the ECU shouldn't cause this. Regardless if you connect a four channel scope like I have previously suggested, and the timing was in fact accurate but the ECU read differently the cams would line up with no deviation side to side. If you check timing with a scope and all the cams are lined up, that is the reading that should be getting back to the ECU, if you get the codes right away then your ECU is likely the culprit. All the bad ME control modules I have ever experienced exhibit complete failure of drivers, no fuel pump activation, no cam solenoid activation, no engine suction fan, no coils, no injectors, etc. I can't think of a single instance that the ECU would shift a signal on two separate sensors to read bad. I'll dig up some examples.
Tensioner is still in. I have just removed front cover, and one pulse wheel. (btw what is the size of torx on the other side of cam?)
Now, when I looked at it again, one mark seems one teeth off. Take a look at the pictures.
Yes, check engine was getting back immediately after erasing fault memory. At first while driving it was on and off for some time, but later it was constantly on. And sometimes I had long crank before start.
OK, I thought you had the whole timing cover apart. It's hard to say with only that cover off and no other reference points. Is it exactly on 40 degrees? Do you have the other side apart for comparison? Based on only those pictures it looks like it is a little retarded. It only takes 4 degrees of difference to set a fault code so it can be hard to see without all the other reference pictures.
Just to be clear "easiest diagnose is just ECU replacement" is NOT a diagnosis. Thats throwing parts at it in hopes that it will fix it. If you were to get codes 1200 and 1208 for right bank timing retarded every time you start the vehicle and the ECU was the fault the diagnosis would be simple. The cam position sensors produce a 5v signal that gets sent back to the ECU, if there were no signal getting back you would have different codes. Having timing retarded codes indicates there is a signal getting back to the ECU but at the wrong time. Excessive resistance within the ECU shouldn't cause this. Regardless if you connect a four channel scope like I have previously suggested, and the timing was in fact accurate but the ECU read differently the cams would line up with no deviation side to side. If you check timing with a scope and all the cams are lined up, that is the reading that should be getting back to the ECU, if you get the codes right away then your ECU is likely the culprit. All the bad ME control modules I have ever experienced exhibit complete failure of drivers, no fuel pump activation, no cam solenoid activation, no engine suction fan, no coils, no injectors, etc. I can't think of a single instance that the ECU would shift a signal on two separate sensors to read bad. I'll dig up some examples.
Thanks @knowbenz for your infomation, i faced 02 case with code 1200 and or 1208 and the codes return immediately when engine restart, we tried all possibilities: camshaft gear replacement, camshaft sensor, Camshaft magnet, fulse ring, timing chain tensioner, balance shaft or even engine wiring but problem still persist and it only disapeared when we do ECU replacement, it also strange for me but my collagues told me that for the error code 1200, WIS also advice ECU replacement as a last action.
Thanks @knowbenz for your infomation, i faced 02 case with code 1200 and or 1208 and the codes return immediately when engine restart, we tried all possibilities: camshaft gear replacement, camshaft sensor, Camshaft magnet, fulse ring, timing chain tensioner, balance shaft or even engine wiring but problem still persist and it only disapeared when we do ECU replacement, it also strange for me but my collagues told me that for the error code 1200, WIS also advice ECU replacement as a last action.
So you threw parts at it until something stuck? See the attached screenshots. I can't stress enough how vital proper diagnosis is to properly repairing modern vehicles. Hooking the scope up to measure camshaft position of all four camshafts takes no more than 2 minutes. Start the program, plug everything in. The signal wire is in the center position and the shroud around connector doesn't even need to be removed once you get the feel for back probing these sensors.
These are the only screenshots I have on my computer but I will get some that better show stretched chain and worn balance shaft faults.
In this screenshot I have marked of the same position twice on the cam sensor signal to indicate 720 degrees of crank rotation. The vertical lines in between are measuring the difference between left and right side camshafts. The bottom right value with red line shows 2.146 degrees difference side to side. More than 4 degrees difference will set a code. These screen shots are from a vehicle that suffered short term oil starvation which can result in damage to the cam adjusters. We hooked this up to get an idea if any damage had been done. Vehicles we have measured with new chain and balance shaft will typically be between 0.5-1.8 degrees difference. This is not bad and no repairs made.
This shows the exhaust cam difference side to side of 2.77 degrees. a little on the higher side compared to new but not alarming for 110k miles.
This is the setup shot to take the measurements. Ever since using this method of proper diagnosis I dont have to remove any components from the car. No wasting time or money throwing parts at the car and crossing fingers, no removing cam sensors to check the plates, no pulling covers, keep your hands clean and diagnose it properly.
As far as the ECU I have my theories that I want to get some screenshots tomorrow that will help better explain.
On 3rd photo the Red & Green cable are probe on intake camshaft sensor then intake and exhaust on 1st & 2nd photo should reverse?
Very infomative, thank a lot @knowbenz Pico 4 chanel scope will be in my shopping list.
I don’t recall if that was the GLK that the scope waveforms were from. Just screenshots I had on computer and the first setup shot I had in my phone as examples. Or I could have mis labeled I can’t remember
Hi @knowbenz Picoscope 4 chanel like your tool quite pricely, do you think the 4 chanel scope below can provide a similar result for Camshaft diagnostics?
Hi @knowbenz Picoscope 4 chanel like your tool quite pricely, do you think the 4 chanel scope below can provide a similar result for Camshaft diagnostics?
OK, I thought you had the whole timing cover apart. It's hard to say with only that cover off and no other reference points. Is it exactly on 40 degrees? Do you have the other side apart for comparison? Based on only those pictures it looks like it is a little retarded. It only takes 4 degrees of difference to set a fault code so it can be hard to see without all the other reference pictures.
Yes, it is exactly 40 degrees. I haven't disassembled other side, as it requires to remove oil cooler, and then new gaskets.
Now I'm thinking, that it should be a chain, or a sprocket, because it doesn't look like anything else.
Evaluating, that sprocket has been changed, and it shouldn't fail second time, (as it was manufacturing problem at the beginning) I will change a chain.
I have ordered from Febi, will not go for OEM again, if they making it from paper.
I
will use method shown in the video below. But there are some things they don't tell, like:
Is there any difference where to split old chain? (it has some coloured slots, I suppose?)
I have bought cam locking tool, but it makes no sense to lock them, because according to this video I have to remove them anyway?
And how do I will alling cams and chain later on?
Yes, it is exactly 40 degrees. I haven't disassembled other side, as it requires to remove oil cooler, and then new gaskets.
Now I'm thinking, that it should be a chain, or a sprocket, because it doesn't look like anything else.
Evaluating, that sprocket has been changed, and it shouldn't fail second time, (as it was manufacturing problem at the beginning) I will change a chain.
I have ordered from Febi, will not go for OEM again, if they making it from paper.
I
will use method shown in the video below. But there are some things they don't tell, like:
Is there any difference where to split old chain? (it has some coloured slots, I suppose?)
I have bought cam locking tool, but it makes no sense to lock them, because according to this video I have to remove them anyway?
And how do I will alling cams and chain later on?
You dont need a cam locking tool. Just remove right bank cams and roll the chain in. Line everything back up at 40 degrees. The left side will be fine as the chain has no room to jump with valve cover on. The brass links dont really matter if you are rolling the chain in. They are more for easier alignment if everything is removed. You can also verify position at 305 degrees looking through the cam sensor holes. Ive had actual cam gears wear out also but never one that constantly threw those codes. It was only while highway driving.
You dont need a cam locking tool. Just remove right bank cams and roll the chain in. Line everything back up at 40 degrees. The left side will be fine as the chain has no room to jump with valve cover on. The brass links dont really matter if you are rolling the chain in. They are more for easier alignment if everything is removed. You can also verify position at 305 degrees looking through the cam sensor holes. Ive had actual cam gears wear out also but never one that constantly threw those codes. It was only while highway driving.
Ok, thank You. Parts arrive tomorrow, so I will proceed.
Will it require some kind of adaptation after replacing chain?
Ok, thank You. Parts arrive tomorrow, so I will proceed.
Will it require some kind of adaptation after replacing chain?
Yes, that was my thoughts to the ECU replacement @minh was referring to. If somehow the adaptations were taken with the timing so far out it may not fully correct with the new parts. Replacing the ECU will reset the adaptation values back to the middle.
I don't have Star at home, so after changing chain I have to drive to MB dealer. But I don't see anything wrong with driving, if I put timing back where it was, right?
BTW, do You know how to access chain tensioner? Do I need to remove alternator?
I don't have Star at home, so after changing chain I have to drive to MB dealer. But I don't see anything wrong with driving, if I put timing back where it was, right?
BTW, do You know how to access chain tensioner? Do I need to remove alternator?
Thanks.
Let do timing chain replacement first to see how it works and you can make camshaft adaptation later on if required.
you need to remove alternator for access chain tensioner, do not forget reset chain tensioner before re-use otherwise timing chain will over tensioned.
I don't have Star at home, so after changing chain I have to drive to MB dealer. But I don't see anything wrong with driving, if I put timing back where it was, right?
BTW, do You know how to access chain tensioner? Do I need to remove alternator?
Thanks.
No, dont worry too much about it. Remove alternator for tensioner. If you have the small one piece tensioner be sure to replace it.
No, dont worry too much about it. Remove alternator for tensioner. If you have the small one piece tensioner be sure to replace it.
Yep, I've spent all day swearing, but removed only 3 alternator bolts. Tomorrow going to buy torx wrench, as it is impossible to access it with socket. That was unexpected delay.
I have new tensioner, it was in set with new chain.
BTW, video states to replace pulse wheels, what's Your take on that?
Yep, I've spent all day swearing, but removed only 3 alternator bolts. Tomorrow going to buy torx wrench, as it is impossible to access it with socket. That was unexpected delay.
I have new tensioner, it was in set with new chain.
BTW, video states to replace pulse wheels, what's Your take on that?
For me replace pulse wheels is not mandatory as long as they are not shear off.
Without a lift then remove alternator 4th bolt is very dificult and you almost can't remove it fro the top of engine bay, there are two tube hanging over this bolt and you need to remove this tube first before able to access the bolt from bottom.
Yep, I've spent all day swearing, but removed only 3 alternator bolts. Tomorrow going to buy torx wrench, as it is impossible to access it with socket. That was unexpected delay.
I have new tensioner, it was in set with new chain.
BTW, video states to replace pulse wheels, what's Your take on that?
We always replace them but like @minh mentioned, if the locating pin isnt damaged you should be able to get away without.
Originally Posted by Minh
For me replace pulse wheels is not mandatory as long as they are not shear off.
Without a lift then remove alternator 4th bolt is very dificult and you almost can't remove it fro the top of engine bay, there are two tube hanging over this bolt and you need to remove this tube first before able to access the bolt from bottom.
4 Matic doesn't have that bracket holding the lines you are referring to but still very tight, I always raise the engine a little for more room and use a ratchet wrench
We always replace them but like @minh mentioned, if the locating pin isnt damaged you should be able to get away without.
4 Matic doesn't have that bracket holding the lines you are referring to but still very tight, I always raise the engine a little for more room and use a ratchet wrench
Ok, I've bought E12 wrench, but bolt is stripped, so it doesn't come on. Strange, but E14 socket still grips, so I'll buy that size wrench tomorrow, and make a last try. I believe next is pulling the engine, if I'll not be able to undo that bolt?
How do You lift the engine? What has to be disconnected? And how high You are able to lift it?
12-31-2019, 04:55 AM
