Hesitation/Shudder from a dead stop to moving

So a little more real world info on the problem. I was entering a parking garage yesterday and there were speed bumps before you enter the garage. I had a sleeping baby in the car so I came to a complete stop before trying to go over it. When I took my foot off the brake and pushed the gas to go over the speed bump the car just did the shudder thing and would not go over the speed bump, so I let the car rock backward and then went forward with a little momentum and I went over the bump. So I am having a real problem with initial power delivery, when moving from a stop. I don't think it has anything to do with the ICE because it was not running when this was happening. I'm really starting to think this trans I put in the car is a piece of junk...

*Is there anyway I could have hooked up some of the HV cables backwards at the plug? I don't think this happened but I am trying to think of everything. Does one HV cable control electric power delivery from take off or do they work together?*

 

I hear you but there is no way this is normal. Mine will shake the dental work out of your mouth.

 

I agree with you, I think I am missing that initial tq, which is causing my huck-n-buck action. I am just not familiar with these cars yet to know what exactly is causing it. The only thing I know is that according to the previous owner the car was fine (other than a cracked trans case) before I put a replacement trans in it. So I am thinking it is probably trans related. This is also my first vehicle with a CVT so I am not sure how they normally fail. With a traditional automatic either the gear will not engage, or it will slip once engaged when it's on it's way out.

 

Assuming Wikipedia is correct here is some info on what does what...I assume most who have been here for a while know this stuff, but I did not. It does make note that MG2 is responsible for smooth acceleration from a standstill....and that is where I am having issues.

MG1 and MG2[edit]

• MG1 (Secondary motor-generator): Acts as a motor to start the ICE, or to generate electrical power for MG2 and to recharge the HV battery. By regulating the amount of electrical power generated (by varying MG1's mechanical torque and speed), MG1 effectively controls the transaxle's continuously variable transmission.
• MG2 (Primary motor-generator): Drives the wheels, regenerates power for HV battery energy storage while braking the vehicle. MG2 drives the wheels with electrical power generated by the engine driven MG1. This is the motor portion of its "motor generator" capabilities. MG2 provides a smooth acceleration from standstill. During regenerative braking, MG2 acts as a generator, converting kinetic energy into electrical energy, storing this electrical energy in the battery

 

I have been poking around on google some and it seems that generating 1 Prius' had a shuddering issue when the MG2 motor was failing. I found a video of LG doing a MG2 stator replacement on a first gen. Can anyone tell me if MG2 stator replacement would be the same on a second gen? If not what is different. I still have my spare trans with the cracked trans case and I am debating on whether or not I should pull the stator out of my current trans and swap it to rule that out.

 

I took the car to the Toyota dealership to have the display/speedometer replaced because mine was going out occasionally. While it was there I asked them to diagnose my shuddering issue. When I got the car back they said there is a problem with the electric operation/MG2 of the trans but it is not showing and dtc codes. They said the problem was internal to the trans. So anyway, I have initiated the warranty procedure on the junkyard trans I bought. I will post back when I have actually had time to pull the trans and swap the new junkyard trans into place.

 

Well, I replaced the trans over the weekend and I am no longer having the hesitation, shudder. I know it is not common for this generation prius but now that the car is driving normal I really think I had most of the symptoms that the first gen prius had with a burn MG2 stator. The shudder, the brake regen was much louder than it is now. I am not going to take the trans apart to find out, because I need to return it for my warranty core. Anyway just though I would update the thread incase anyone else runs into this problem. Also, if you are at the point of removing your trans do yourself a huge favor and remove the sub-frame, it makes life so much easier once it is out of the way and with a few jacks it's really not that hard to put back in.