2009 F02 BMW 750Li Drivetrain Torque Converter Hard Jerks/Thumps

[roshaan]

Hey guys!

I've been having this issue for a really long time now but still haven't been able to solve it. I recently replaced the Torque Converter as my car was jerking in lower gears while accelerating. Now that I've changed it, from speeds between 31 mph to 68 mph when I accelerate suddenly there is a big jerk almost like a thump as if someone has rear ended me. I took it to my dealer he says its the real axle rubbers that need to be replaced. I also have these errors displayed during the diagnoses beside many others:

1D2404 Map thermostat, activation: open circuit
400201 Converter lockup clutch, slip too great
400606 Output speed sensor, short circuit to ground or open circuit
D39578 Signal (Powertrain wheel torque, 0xDC) invalid, transmitter DME/DDE F02

I really need help guys I'm going crazy with these jerks especially after spending so much money on this car there always seems to be some issue!

Thanks!

[ChristopherF01]

Hey guys!

I've been having this issue for a really long time now but still haven't been able to solve it. I recently replaced the Torque Converter as my car was jerking in lower gears while accelerating. Now that I've changed it, from speeds between 31 mph to 68 mph when I accelerate suddenly there is a big jerk almost like a thump as if someone has rear ended me. I took it to my dealer he says its the real axle rubbers that need to be replaced. I also have these errors displayed during the diagnoses beside many others:

1D2404 Map thermostat, activation: open circuit
400201 Converter lockup clutch, slip too great
400606 Output speed sensor, short circuit to ground or open circuit
D39578 Signal (Powertrain wheel torque, 0xDC) invalid, transmitter DME/DDE F02

I really need help guys I'm going crazy with these jerks especially after spending so much money on this car there always seems to be some issue!

Thanks!

Check out this thread:
http://forums.bimmerforums.com/forum....php?t=1235885

Just read the response excerpt from TiMM:


"The fault is due to the lock-up clutch within the torque-converter. The clutch is normally only locked (engaged) when cruising in 4th and 5th gear. It is used to reduce losses in the torque-converter, without the lock-up clutch, the pump and turbine 'slip' in respect to each other when cruising, this reduces fuel-economy. When the lock-up clutch engages it mechanically locks the pump and turbine so no energy is wasted.

The way the lock-up clutch is controlled is more complicated in the later models, instead of a simple ON/OFF control, the clutch can be proportionally engaged to reduce converter losses. It is during this proportional phase that the shudder occurs. The shudder is the same sort of shudder you can get from an oil-contaminated manual clutch.

What you will find is that you can drive around the problem by using Sport or manual modes. This is because the lock-up clutch is controlled differently in those modes. The shudder also goes away when heavier throttle is applied, this is because the lock-up clutch is fully disengaged to provide torque-multiplication (which is the torque-converters main task)."