If you are referring to resetting the TCM shift parameters I haven't completed it yet and will comment on it's success or failure when I have attempted it. To answer your question, if you are referring to resetting the TCM fault codes to allow the loss of drive or LHM to be cleared from system memory allowing a "normal, as it should be" drive condition. That's when the decision to rebuild the transmission was made and ultimately what fixed the loss of drive problem. ![]() When I started the engine and threw it in to drive I got no power to the drive wheel and realized the conductor plate didn't fix the problem. I did do a resistance check with an ohmeter (at the TCM harness connector under the drivers seat) on each of the solenoid circuits after the new conductor plate was replaced and each individual circuit was in the accepted value range deeming each solenoid circuit functioning properly. After the new plate was in and fluid up to proper level, I successfully cleared the Y3/6Y2 fault code and after several key cycles it had not returned. This is the plastic electrical circuit board that the connector from the TCM wire harness attaches to in the Mercedes 722.6 NAG 1 transmission. I replaced the conductor plate on the valve body because after researching what could cause the Y3/6Y2 fault code to trigger a DTC, I found the conductor plate more than likely was the reason due to the high failure rate of these electrical circuit boards. After I first was able to successfully link to my TCM with the LAUNCH CRP scan tool via the OBD2 port ( by selecting the Viano OBD2 icon in the drop down list after selecting Mercedes Sprinter), the Launch CRP 123 showed the Y3/6Y2 shift pressure control solenoid circuit was faulty. I do have some tools from the previous Transmission builds but I am lacking at least one tool to do this trans which is a press for the K 1,2,3 and B 1,2,3 drums for frictions replacement, which shouldn't be too difficult to make.Ĭlick to expand. I probably could use a little nudging before I tear into this for a complete disassembly as maybe it isn't a mechanical failure and I am overlooking a electrical problem that is causing this "Stuck in the driveway" mode. When in park both show "P", when in neutral both show "N", When in reverse the targeted gear shows "R" the actual gear shows "N", when in drive targeted gear shows "D" actual gear shows "N". The Scantool is a LAUNCH CREADER PROFESSIONAL CRP 123 and shows the "Targeted gear" referring to which gear the selector is in and "Actual gear" which i"s what the computer is telling the scantool which gear the trans is actually in. I reinstalled the valve body, refilled with Shell ATF 134, cleared codes on the TCM and ECU and after several key cycles and engine run time no codes have returned but still have complete loss of drive. Both rebuilds were many years ago but the ATSG guides for each of them were easy to follow and both transmissions worked perfectly when completed. I trust ATSG as I have used their guides before, first in 2002 when I rebuilt my Chevy Turbo 400 out of my '70 Corvette and then in 2005 for my Jatco trans out of my '89 Isuzu NPR. After replacing the plate, I tested each solenoid with an ohmmeter at the TCM connector and found the values on all solenoid circuits within the acceptable range according to the ATSG 722.6 Transmission Service Manual. After reading several different articles on the history of the 722.6, I replaced the conductor plate on the valve body because I learned there are issues with this part and it is more than likely is what is causing the fault code to appear. Initially this tool pulled a Y3/6Y2 fault code in the tcm referring to the shift pressure control solenoid valve being faulty. A, I followed his suggestion in focusing on locating a DAD or DRB III or Snap-on Modus to see what codes were stored inside the modules but I have not been successful in my search but I found a tool that seems to communicate with my TCM and reads,erases,and displays live data from all 3 shift solenoid circuits as well as torque converter lock up solenoid and both pressure regulating solenoids and speed sensors. ![]() After cleanup of both TCM connectors and the electric terminals on the TCM I was hoping that that would be enough to put me back on the road.Īfter a brief conversation with Dr. Both connectors at the TCM were dripping with ATF but no fluid made it inside the module. ![]() When I discovered ATF had launched a full scale attack on my TCM with a little help from the wire harness that goes to the leaking NAG1 electrical connector at the Transmission. It's been a almost a month since the transmission failed on the fwy and now I am leaning more toward mechanical failure as opposed to electronic failure causing complete loss of drive. ![]() This morning I am pulling the trans out of my 2004 Freightliner 158" and disassembly begins.
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