Torque converter Lock-up

[drbrandini]

Hello all,

It looks as though I am experiencing torque converter lock-up on my 1997 E320. Thanks Ali for helping me diagnose!! What needs to be done to correct this problem? do I need a new transmission controller? If so, have an estimate of what this may cost? Is it a DIY'r job? I am currently driving the vehicle as my daily driver.

Thanks for your help

[Ali Al-Chalabi]

Yes, the problem I suggested is the lockup clutch is not allowing the scheduled amount of computer controlled slip to dampen the vibrations. As discussed in the previous thread, the lockup clutch should engage at those speeds but should modulate the pressure applied to the lockup clutch to allow about 60 rpm or so of "slip." If it does not allow for any "slip" it will produce those driveline vibrations.

[C32AMG]

Do you mean a converter shutter, chatter? If so.


The torque converter clutch apply is pulse width modulated and duty cycle controlled.

You have to retrieve any stored codes. The only code that would not put the Trans into a limp mode is DTC 53, “torque converter lock up clutch slipping.”


The way too diagnose the cause is with a scanner, looking at data parameters:
Pressure torque converter lock up
PWM solenoid valve status
Shift valve duty cycle
Slippage RPM valve




Some times a fluid change (Flush) will fix the chatter. I know the fluid is expensive but it might be worth the expense.

[drbrandini]

C32,

Thank you for the reply! That helps.

I do not have a scanner, So I guess I need to take it in. The fluid was changed about 38K ago. (Using 60K intervals). Should it cost me very much to take it to my indie for this? Is this something that I would be better off taking it to the dealer for?

[C32AMG]

If I were you, the dealer would be my first choice; the fix could be a soft ware update. For my future knowledge post what they find. Good luck.

[drbrandini]

C32,

I took the car to my Indie today to address this issue. He wanted to start by pulling the codes from the engine, TCU and traction control. The engine and traction control modules were clear. The TCU came up with these codes: 114, 132 and 135. He said none of the codes were really pointing to one thing and were really inconclusive. He then cleared the codes, drove the car again, and checked the codes, and got nothing. He checked the trans fluid and said the level is fine and it's not leaking anywhere but it is very burnt and needs to be changed. (last changed 129,000..currently at 149,000). He said we should start by flushing the trans completely and changing the filter. What say you guys?

He said the fluid flush and change will run 148.00. He charged me 124.00 for pulling the codes and the complete checkout today...He also changed a few light bulbs and put a new grommet on my washer fluid resevior so that it will hold fluid again... and didn't charge me for the later. He also talked to me for quite a while explaining the systems of the car. This only the second time I've used this shop (Inter Shop). I feel like these prices are fair...what do you guys think?

[C32AMG]

132and135 are CAN codes, the modules don’t “Hear” each other well, probably caused by the 114 code; “Transmission gear selector lever in between selections” The transmission doesn’t know what gear it’s in. The shift linkage could be out of adjustment or the range switch is defective, shifter. There is a slight possibility this may be your torque converter problem. If code 114 reappears with the “CAN” codes let your tech fix the 114 code first as this is most likely the cause of the “CAN” codes.


$148 is a good price for a flush, are you sure he flushed the Trans with MB fluid. It takes at last 16 qts of fluid to thoroughly flush a 3.2L.

[drbrandini]

C32,

Thanks for the reply!

Is this switch possibly something I could change? I wanna say I saw that the shift linkage bushings had been changed recently in the records, though it does seem a hair more loose than my 124.

I haven't had hime changed the fluid yet, I'll ask him again just to make sure he quoted me correctly.

[C32AMG]

The most important step is to replace the BRUNT fluid. Not changing it is doing more damage. You can check the voltage output reading of the range sensor to the transmission control module. If you what to check it yourself I can post the steps. The tech should have check it with the scanner and recommended a fix. Check the linkage rod for movement.

[drbrandini]

Thanks C32,

I was actually going to call tomorrow and schedule an appointment to change the fluid.

I'll ask them to test the voltage output as well.

Thanks for all your help, Ill keep you posted.

[drbrandini]

C32,

Car is in the shop as I speak getting a transmission service. They are going to dig around a bit to try and find the culprit. I asked him about the voltage output reading....he said he checked it when he pulled the codes...he said it reads that at the same time ??? If you can think of anything else, I'm all ears..thanks

[C32AMG]

My main concern would be the condition of the pan, any large pieces of medal or clutch material. When I do a flush I like to remove the pan inspect it, change the filter, clean the pan then flush, only if it’s clean. If there is excessive metal or clutch material the transmissions is failing. Good luck.

[drbrandini]

C32,

Well good news for the most part I guess. He noted on the receipt that he removed the pan, changed the fluid and filter. He said the flush ended up taking about 18 quarts !! He charged me 192.00 total. Thought that was pretty fair. He said that there was nothing in there that would lead him to believe that there is anything wrong with the trans. He speculated that the two other times that the trans had been serviced at the dealer that did not change the filter. He did show me the old fluid...it was nice and burnt though, but no particles or metal peices !

I still feel the hint of vibration but haven't felt it hard.....as of yet.... But I've driven it probably 12 miles since I've picked it up... I'll keep you posted.

[Kebowers]

Lubeguard Red will definitely smooth out a grabbing clutch.

[Ali Al-Chalabi]

Sounds like a very good price.

Do not use any additives in the 722.6 or anything other than MB specific fluid.