Hello everyone! I have a question for the transmission guru's out there.
I just had to replace my transmission because the overdrive planetary burned up and the car went into "Limp Mode" once I finished the install, cleared the DTC's and took it for a drive, had a sudden jerk, then the dreaded Neutral light/cel light came on, had the same two codes-
P0750 and P0755 (shift Solenoids A & B malfunction) the dealer tells me it's either a bad PCM or the VSS/and or wiring from the VSS to the PCM is bad. how do I check the VSS? Ohm meter? I also question wether or not the correct gear was installed on the VSS, I found two different sizes of gears available, if the smaller of the two gears was used, is it possible it isn't meshing with the gear on the differential housing? how many teeth should be on that gear? or is there a particular diameter of a gear I am looking for? I am hoping this is the case, and I don't have to buy a PCM.
Let me know if there is anything else I can do to get past this. I'm at my wits end......

Thanks!
Ben Smith

 

anyone know if there is a certain size gear required for the VSS sensor on a 2000 Eclipse GT 3.0? I have just replaced my transmission in my GT and the computer says I have a bad VSS or broken/or bad connection to the sensor, basically, the transmission is not getting the VSS signal, I question wether or not the VSS sensor is even turning while the car is moving (Incorrect gear diameter, not meshing with the gear on the differential) I have a few VSS senors I got from the salvage yard, and found most to have the larger gear, but the original one had a smaller gear, I'm wondering if the VSS mounting hole was moved in other applications, or simply, that my sensor has the wrong gear from the get go. my speedometer does work, so I am not sure if it gets it's signal from this sensor, or that maybe one of the other speed sensors is faulty, like the two on top of the tyransaxle case. Can anyone help me out here?
Thanks in advance!
Ben Smith

 

Okay, perhaps I'm asking the wrong questions, or simply, no one knows how to answer these questions? I'm at my wits end and ready to have a fire sale........
Took the car to the local mitsubishi dealer, told me what I already knew, code P0750 and P0755 (shift solenoids A&B Malfunction) the tech said the the PCM wasn't getting a signal from the speed sensor, didn't elaborate as to which sensor was at fault, but I'll find out tonight when I pick up the car.

my car is a 2000 GT 3.0 Eclipse, sportronic shift transmission, the car had gone into Limp mode before I replaced the transaxle, I found the overdrive planetary shell and gears were fried in the old transaxle. I bought a 60k miles used transaxle and swapped them out. changed the filter out before re-installing the trans. put new fluid in, and test drove the car, didn't get one block before immediately going into limp mode. one question I have is this: I know there are two main sensor for the trans- Input speed and output speed, found those easily, but the service manual makes no location for the VSS sensor in the transaxle section. it is in the combination meter section. I changed this sensor out to make sure it was working, and correct me if I'm wrong- if this sensor wasn't working, I would not have a functioning speedometer,correct? any ideas as to how I can fix this problem? I'm guessing one of the sensors, input or output has gone bad, but I'll have to ask the dealer which one they found.
Thanks in advance!
Ben Smith

 

Ok Folks, I took my eclipse to the dealership to have it diagnosed, all they could tell me was what I already know-
a little history on this car-
I first noticed the car was slipping in and out of gear shortly after buying the car, then one day,it jerked hard, and went into limp mode, and the neutral light started flashing, and the check engine light came on.shortly after that, I started hearing a whining/light grinding noise, so I bought another transmission, re-installed it, and test drove the car,codes P0750 and P0755 (Shift Solenoids A & B Malfucntion) same problem all over........
the tech said that the Output sensor was bad, or the wiring from that sensor to the PCM was bad, or has a short, worst case, the PCM was bad. after spending $100 bill,for the short diagnostic, I took the car home and went to work. tracing and probing the wiring harnesses and connectors to find my short. I couldn't get to the area of the firewall where the main harness comes through, so I went about removing the blower motor housing and some of the duct work to get to the PCM, I wanted to rule that out of the equation. Once I had the PCM disconnected, I went back to my harness and Voila! the ground was still there.....so, I put the PCM back in place, returned the blower motor housing and went back to tracing the harness short, to make a long story short, the car has a "Sportronic" Transaxle,well, the one of the wires coming from the input speed sensor,output speed sensor and park/selector switch were black with an Orange tracer, I happened to glance at the shifter wiring, and wouldn't you know it....there was a black wire with Orange tracer. I disconnected the switch from the harness and no more grounds......I have yet to drive the car, but I am confident I found the problem. I'll dig a bit deeper into the factory service manual and see how to test/diagnose thatsportronic shifter switch. I hope I can save someone the aggravation I just went through and avoid a similar situation.
So, if anyone else has a smiliar problem, and from what I have been reading, it's a very common problem with these mitsubishi transaxles.
Hope this helps!
Ben Smith
Please let me know if there is anything I may have overlooked.