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Discussion Starter #1
Good day guys

Im hoping you guys can assist me in testing some solenoids. First time ever for me, so not quite sure where to start. I did some Googling, but I cant seem to find where all this testing is done. Might have overlooked it :-(

Anyway, Im stuck in limp mode on my W210 with a 722.606 tranny and my iCarsoft scanner gives me a error code of P0748, a generic code yes. The scanner says its "pressure control solenoid 'a' electrical". I know where the solenoid sits, but wanted to know how I go about testing it. Besides draining tranny fluid, removeing sump and all that. I got some diagrams, resistance values of individual solenoids and images from Google, suggesting various pinouts to check, but i'm unsure of how to go about it all. Is all this done with ignition on or off? Will I be doing all tests by the 38pin connector etc.

I would greatly appreciate it if someone can give me a rundown of how this is suppose to be done, or even a link of how its done.




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Here is recent thread about solenoid testing.

 

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I just want to understand this. So the TCU logs its own fault, then sends that same fault code to the ECU. So clearing the ECU fault codes wont clear the TCU fault codes. I have the iCarsoft MB v1 scanner, which cannot access the TCU with the non iCarsoft 16-38pin adapter cable I bought separately. So everytime I clear the ECU codes, that same P0748 code comes back again. So after every restart the TCU sends the ECU that same code. Im going to test the solenoids and whatever else I can, while I wait for another guy to bring his Star diagnostic machine along. Same guy I have been waiting a month for lol.

When I asked the tech support at iCarsoft if it would clear transmission faults, they said it would. That was obviously dependent on having the original iCarsoft 16-38pin adapter.
 

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So to test solenoids I could just unplug from the transmission control unit and test from the plug? Lets say I wanted to test Y3/6Y1 and Y3/6Y2 at the transmission control unit plug, what terminals should I be probing? I assume that I would put one lead of my multimeter on terminal 36 or 37, wo where do i put the other meter lead? Would that go terminal 38? Accordign to the diagram it looks like comon to all solenoids. I understand that should I get less than the specified values, the fault could be further down towards the conductor plate terminal. Which Im going to replace in any case.
 

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Discussion Starter #6
Started at the transmission control unit. And this is what I found. Oil, and a blown 100uf 35v cap. Scratched through my parts and I only have a 100uf 16v cap. Would that work as a replacement?

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I just want to understand this. So the TCU logs its own fault, then sends that same fault code to the ECU. So clearing the ECU fault codes wont clear the TCU fault codes. I have the iCarsoft MB v1 scanner, which cannot access the TCU with the non iCarsoft 16-38pin adapter cable I bought separately. So everytime I clear the ECU codes, that same P0748 code comes back again. So after every restart the TCU sends the ECU that same code. Im going to test the solenoids and whatever else I can, while I wait for another guy to bring his Star diagnostic machine along. Same guy I have been waiting a month for lol.

When I asked the tech support at iCarsoft if it would clear transmission faults, they said it would. That was obviously dependent on having the original iCarsoft 16-38pin adapter.
Yes, that's how it works. You have to clear faults from both units.
 

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So to test solenoids I could just unplug from the transmission control unit and test from the plug? Lets say I wanted to test Y3/6Y1 and Y3/6Y2 at the transmission control unit plug, what terminals should I be probing? I assume that I would put one lead of my multimeter on terminal 36 or 37, wo where do i put the other meter lead? Would that go terminal 38? Accordign to the diagram it looks like comon to all solenoids. I understand that should I get less than the specified values, the fault could be further down towards the conductor plate terminal. Which Im going to replace in any case.
Pin 38 is power supply, ETC applies ground to operate solenoids.

To make this easier and to assure reliable connection slide connector cover off. Cut zip tie, lift cover over detent and slide it off.

IMG_20180903_092854.jpg




Probe from the back or front. Insert probe beside terminal to avoid spreading it.

IMG_20180903_093538.jpg



Set of back probing leads helps.

IMG_20180903_092640.jpg
 

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Discussion Starter #9
O one lead of my meter would go to pin 38, the other would got to whatever solenoid I want to test?
 

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Oooh, are you guys gonna have a laugh now.

So while replaceing the 13pin connector, plug was full of fluid by the way, I BROKE THE DAMN 7MM NUT WHILE TIGHTENING IT. it simply snapped off, I hardly put any stress on it. Spent the good part of 2 hours trying to get it ou without removing the sum and all the other bits. I had to reuse the 7mm nut from the old connector. A couple of bent pins, another 30 mins to straightne them up and make sure they all lined up, used the old connector to check they all lined up. Im finally done with it. Now to get that dude to come and clear the codes from the tranny. Gosh Im bushed man
 

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Discussion Starter #12
By the way, I found a few 100uf 35v caps in my sock draw, I have no idea how that got there. So got the right voltage in there as well.
 

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Discussion Starter #13
Would it be safe to say, that should I disconnect the loom from the transmission control unit, I will be able to apply a 9v source to the loom and hear the individual solenoids tick? I know the solenoids should not be kept on a voltage source continously as they could be damaged.
 

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Discussion Starter #15
Thank you. Its Heritage day tomorrow in SA, so a public holiday for us. Gonna get into it tomorrow.

I bit off topic here. But I recently bought a iCarsoft MB v1 scanner for my W210. I also had to get the extra 38-16pin adaptor cable. Even with this adapter cable Im still not able to access any of the modules provided. No tranny or ESP or ABS etc etc. I contacted iCarsoft, and was assured that it can access those modules with there own 38-16pin adapter.

Do you guys know if there is something like a passive or active adapter? Are they all wired the same etc

Thanx in advance

Cedric
 

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You need to get their special adapter. The cheap adapter cables only access the ECU, as they have power+ground+ECU access pins end to end.

You should check it with ICarsoft if they support TCU scan and reset with their adapter and software, specific to your car model and model year.

 

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Discussion Starter #18
W210 listed, provided you take there 38-16 pin adapter they have. Our local supplier does not have stock, so I purchased a cheapy one elsewhere. Doesnt work, I can only access OBD functions, no individual modules.

When I asked the local supplier about the adapter, I was told its a chinese one in any case. So trying to get one directly from iCarsoft.
 

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I do not think the adapter has any electronics in it. Just mapping a OBD2 connector pins to the 38 pin connector pins with cross-wiring. If you know what pin Icarsoft uses at the OBD2 end when it is trying to test the TCU, you can map that pin to the 38 pin connector pin 10. I have a scanner that needed a special connector. I built my own adapter cable till the actual cable adapter set had arrived.
 
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