Glyn M Ruck

You can copy a link over there but all the guys I mention spend most of their time on this forum. Less BS.

Dingleberry

is it worthwhile to disconnect the battery overnight in an attempt to reset TCU adaptations such as lockup event and shift points? just trying to exhaust my options before getting fleeced at the stealership.

Glyn M Ruck

You can try that. I'm not convinced it will achieve anything. Please read the sticky at the beginning of the 203 forum on what to expect if you disconnect the battery. You will have to resynch everything.

Dingleberry

i disconnected the battery for 15 minutes - no change.

Dingleberry

is the person inputting the tags indicating that they were "high" while coming up with said tags?

Glyn M Ruck

???? - Sorry I don't get it!

mtnman82

I came back to a majorly infected computer - damn Internet Security 2010 virus, very nasty, you all beware. Simply clicked on a U-Tube link and BAM!

Anyway, I did try the same procedure as in the video posted - I'll try to record some video to post too, but no promises at the moment. I had my tranny in 'W', cruising @ 40mph. if I gently pushed on the gas, the rpm's followed the mph's, as in your video (convertor locked up). However, when I let up on the gas, the rpm's don't drop (i.e. convertor doesn't un-lock), just slowly go down w/vehicle speed. After letting up on the gas and dropping to just below 40, if I apply ~30% or so throttle the rpm's jump up (i.e. tranny downshifts, or torque convertor unlocks, or both) and stay there - no bounce or anything other than the shift.

Again, this is on my c230K with the 1.8L... Best of luck with it - I'll be keeping my eye on this thread, & Glyn is an invaluable source of information on these vehicles.

Dingleberry

thanks. try it again, but this time do this: cruise at 40mph, coast down to 30mph, then give it 10% throttle. your car has less torque, so your tcu is programmed to unlock and downshift at lesser throttle inputs. for example, if i give it 50-60% throttle, it wont do that silly lock up problem, instead it will downshift just like yours does.

Dingleberry

i was just kidding. there are a bunch of misspelled tags as well as completely unrelated tags, as well as a tag that says "high"

Glyn M Ruck

Duh! Yes - now I'm with you "tourque"

Kar don

My CLS with a 722.9 does the same thing but after the lockup it will typically unlock and downshift.

mtnman82

Just re-read your original post. I'll try it and again and post results...

Dingleberry

http://www.justanswer.com/questions/...motor-at-lower

Glyn M Ruck

If the 7G is harsh when it does it something is wrong. Some 7Gs did this but it's been fixed with software changes. A few required repair.

Glyn M Ruck

It's possible that a bad actuator might cause the box to mess around. Can you borrow a known good throttle body from someone? I hate to argue with a MB Tech but you sometimes have difficulty measuring a duff actuator. They chatter in reality but measure fine. They only show up as bad if they go open circuit.

Dingleberry

i have nobody to borrow one from. i will get my car scanned for any codes just to see. perhaps resetting the throttle valve adjustment as that tech mentioned might be helpful too.

Utahkompressor

Is that a check engine light in your video?

Dingleberry

wow, i never noticed that before

do you think that could be a problem?

Glyn M Ruck

Read the codes. Let's see

mtnman82

Tried to take a video with my camera, but it sucked... I did as you described above and observed the same thing a before - it downshifts relatively smoothly, you can see/feel the TC unlocking and then the tranny downshifting. Also, my TC doesn't seem to unlock fully when I let off the throttle (i.e. my rpm's don't drop like yours).

I DO notice this behavior when I'm making a slow right hand turn (sometimes left turns if I'm going slow enough - it's a speed thing, not a rh turn/lh turn thing): the rpms will rise, as if to match gearing, but then it'll clunk into a higher gear (i.e. lower rpm's). This is more predominent when the car is cold.

Please let us know how it's going. Did you find any codes associated with your check engine light?

Dingleberry

so it appears that you also have the harsh lockup

i checked with a scantool, the CEL is for a fried secondary air pump.

i do plan on taking the car to the dealer to see if any hidden codes that only star can read are showing

jedcred

Here's that "some guy" chiming in

I'll try to take a video as well once I'm back in my car; won't be for another two weeks yet. Driving my Spec Miata around ATM, and having quite a bit of fun, despite the harshness.

When I complained about this the dealer did say that they updated the transmission computer, with no change. I hope they didn't have more than one upgrade for the TCU software...

The only thing I can add is that, after an ECU tune, it happens much less often, though it only really happened at very low throttle application. Given that, valve body may make sense, though it would have to have been bad from day 1...or day 365.

Dingleberry

interesting

splinter

After having enjoyed an introductory (for him) closed course track day with a youngster aboard sharing incident avoidance skills while exploiting the subtle nuances of repeatedly exceeding its tires’ friction circle capabilities during longitudinal and lateral dynamic maneuvers, our C’s oft recalcitrant torque converter was once again behaving as it should during the drive home and subsequent night about town.

Suppose it’s fair to surmise that those ******* exiled in Affalterbach engineered their machines to be regularly driven as intended?

Dingleberry

do you pay attention to how the torque converter behaves when the car is absolutely cold. i'm talking about when the car i just first started up in the morning - do not let it warm up. the tcu allows the torque converter to slip all the way up to 2300rpm where it holds the rpm there and the car continues to accelerate at the same rpm (just like "normal" automatics) but then once the car warms up in about 1-2 minutes, the TCU changes to a different program where the converter does not slip at all, in fact, as you give it gas, it the converter fully locks the rpms down to 1500rpm or so - as you give it more gas (40%), the converter unlocks again/gear shift event.

this is so obvious that it's a software issue. it's pathetic that we don't have a solution for this from MB or from a tuner...