7G-Tronic - Dealer Update Causes A Problem - PeachParts Mercedes-Benz Forum

DUTCH · #1 08-25-2007, 03:05 PM

I had my 2007 ML320CDI into the dealer for repair of the AirMatic, and made the mistake of asking if there were any software updates for the tranny. I told the SA that very infrequently I would get a very minor hard downshift from 2->1 or 3->2.

Four days later I got it back. They flashed the software and then got some sort of DTC, so they replaced - depending on which time the SA was telling me what they did - either the clutch pack or what used to be called the kick-down-cable. This part had to be ordered and required removal of the transmission to R&R.

I picked it up today. I didn't notice any hard downshifts (they were almost unnoticeable before I brought it in, anyway); but the transmission, which used to be silky smooth on all upshifts before, now has a definite "bump" each time it shifts up a gear - even on gentle acceleration.

Could this be because it hasn't completely adapted to my driving? Thoughts?

(Remind me never to mention minor niggles to the SA again!)

DUTCH · #2 08-25-2007, 04:17 PM

Just had it out for another drive to run some errands. It's hard shifting up and down the entire drive train; where it used to be silky smooth. If anything, it seems worse now than the first drive home from the shop. They sure screwed something up.

Just got off the horn with my SA, who says that he doesn't think that it will adapt itself to smooth operation. Says to bring it back, which means another 1 hr drive in each direction; and what's the technician, who "really did a good job on it" the first time, going to do this next time around!?!!

Robert W. Roe · #3 08-26-2007, 01:49 AM

My R320 shifts are silky smooth well over 90% of the time.
Shifts are only noticeable when I'm in manual shift mode and I'm running the engine up to redline on upshifts.

As to your ML, I would take it to a different dealer... my thoughts are:

Your ML is brand new, under a factory warranty, the beauty of which is, if you take it to a (hopefully) better dealership, it's still under warranty.
I would just tell them you had it to a different dealer's shop, and you didn't like their work because they made your brand new ML shift horribly.

Anyway, I would check the good shops forum for your state; I'm sure Atlanta has way more than one MBZ dealership.
I know Philadelphia has four to six Authorized Mercedes-Benz Dealers within a few dozen miles of each other.

Good luck.

DUTCH · #4 08-26-2007, 06:39 AM

Quote:

Originally Posted by Robert W. Roe

As to your ML, I would take it to a different dealer... my thoughts are:

Your ML is brand new, under a factory warranty, the beauty of which is, if you take it to a (hopefully) better dealership, it's still under warranty.
I would just tell them you had it to a different dealer's shop, and you didn't like their work because they made your brand new ML shift horribly.

Anyway, I would check the good shops forum for your state; I'm sure Atlanta has way more than one MBZ dealership.
I know Philadelphia has four to six Authorized Mercedes-Benz Dealers within a few dozen miles of each other.

Good luck.

Thanks for the tip.

ILUVMILS · #5 08-26-2007, 11:44 AM

If the problem began after the transmission was disassembled to repair a different issue, it seems likely that the problem was caused by the dealer. If the dealer did make a mistake while performing the repair work, it's their responsibility to correct it. They can't charge MB warranty to fix a problem that they caused. Taking it to another dealer will only complicate the situation further.

Take the advice of your SA and bring it back. If possible, go for a test drive with the Shop Foreman to make sure that everyone's on the same page. Ask your SA to follow up with the Tech/Foreman while the work is in progress. They most likely keep a close eye on "comebacks" to make sure the problem is resolved before things get ugly.

Let us know what happens.

DUTCH · #6 08-26-2007, 01:21 PM

Quote:

Originally Posted by ILUVMILS

If the problem began after the transmission was disassembled to repair a different issue, it seems likely that the problem was caused by the dealer. If the dealer did make a mistake while performing the repair work, it's their responsibility to correct it. They can't charge MB warranty to fix a problem that they caused. Taking it to another dealer will only complicate the situation further.

Take the advice of your SA and bring it back. If possible, go for a test drive with the Shop Foreman to make sure that everyone's on the same page. Ask your SA to follow up with the Tech/Foreman while the work is in progress. They most likely keep a close eye on "comebacks" to make sure the problem is resolved before things get ugly.

Let us know what happens.

Good things to consider. Thanks for pointing them out. I am, however, very reluctant to turn it back over to the technician who "did a really good and thorough job on it" the first time, according to the SA.

This same SA, when I expressed concern about a mechanic doing this kind of work by the flat rate manual, tried to tell me that there were no flat rate recommendations or restraints when it came to MBUSA Warranty Claims. And we all know that's not true. I can read a TSB as well as anyone else; and they always have a time allowed for the job proviso.

I won't be able to get it back to that dealer for at least a week, and have to use the truck for a 1400 mile business trip during that time. Perhaps, it may "adapt"; and let's hope it doesn't leave me along side of the road - but that's what TeleAid is for, I guess.

myarmar · #7 08-26-2007, 06:49 PM

It maybe just adaptation issue. If dealer replaced clutch and did not do adaptation it may be the problem. It is not adaptation to your driving style. This adaptation for control module to learn new fill time and pressure for replaced clutch.
You could try to do it yourself. Get transmission to normal operating temperature. Turn AC off. I don't have exact procedure for 722.9, but in general you need to drive the car with very low torque and do not go over 1800 RPM. Put gear selector in 1st, and start driving with very, very light throttle. Manually shift to second. Repeat 5 times. Repeat same procedure for each gear 5 times. You could try to adapt worst gears first to see if you could improve shifts. Again, very low torque and max 1800 RPM are the conditions. Now adapt downshifts. Accelerate normally to the 7th gear and let it coast and downshift to 1st by itself, no braking. Repeat 5 times. After all this let engine idle at least 10 minutes to be sure adaptations are recorded in the memory (this happens once every 10 min). Dealer would have a computer connected to transmission to show adaptations and torque and RPMs for each shift during the process.
Mike

DUTCH · #8 08-26-2007, 07:22 PM

Quote:

Originally Posted by myarmar

It maybe just adaptation issue. If dealer replaced clutch and did not do adaptation it may be the problem. It is not adaptation to your driving style. This adaptation for control module to learn new fill time and pressure for replaced clutch.
You could try to do it yourself. Get transmission to normal operating temperature. Turn AC off. I don't have exact procedure for 722.9, but in general you need to drive the car with very low torque and do not go over 1800 RPM. Put gear selector in 1st, and start driving with very, very light throttle. Manually shift to second. Repeat 5 times. Repeat same procedure for each gear 5 times. You could try to adapt worst gears first to see if you could improve shifts. Again, very low torque and max 1800 RPM are the conditions. Now adapt downshifts. Accelerate normally to the 7th gear and let it coast and downshift to 1st by itself, no braking. Repeat 5 times. After all this let engine idle at least 10 minutes to be sure adaptations are recorded in the memory (this happens once every 10 min). Dealer would have a computer connected to transmission to show adaptations and torque and RPMs for each shift during the process.
Mike

Mike,

Thanks for the feedback. The Shop Invoice lists "OPCODE 271047 Adaptation Perform (After Repairs) 537 W93", so it appears that this was done.

The only parts listed are a bunch of different screws, a gasket and a disc support. No mention of a kick-down-cable or a clutch pack, as the SA said they had to replace. Just a "Control Module Update", which sounds like a software flash to me.

I have to drive this thing on a 1400 mile business trip this week. If it doesn't leave me by the side of the road, I'll have to make a decision about what to do when I get back. With a little bit of luck, maybe it'll smooth itself out by that time.

I can hope!

DUTCH · #9 08-26-2007, 08:01 PM

Quote:

Originally Posted by myarmar

It maybe just adaptation issue. If dealer replaced clutch and did not do adaptation it may be the problem. It is not adaptation to your driving style. This adaptation for control module to learn new fill time and pressure for replaced clutch.

How does a dealer's service tech do this? Dyno? Certainly not on the road. Curious.

myarmar · #10 08-26-2007, 08:27 PM

I guess either way. I have a training video showing the process on W211 on the road. Unfortunately it is about 30 meg file. But I found pdf procedure for 722.9. PM me your email, I'll send it to you if interested.

DUTCH · #11 08-26-2007, 08:33 PM

Quote:

Originally Posted by myarmar

I guess either way. I have a training video showing the process on W211 on the road. Unfortunately it is about 30 meg file. But I found pdf procedure for 722.9. PM me your email, I'll send it to you if interested.

PM sent. Many thanks!

Fourdiesel · #12 08-30-2007, 07:43 PM

Dutch
I had (am having) a similar problem with my GL320 CDI. Took it in 3 weeks ago to have a "sticking" upshift checked out. Turned out that with the instrumentation on the car the tech was able to confirm that the 4-5 upshift was occasionally not happening when it should (or when it was commanded to by me). Dealer ordered a new 'valve body' in, installed it and did a ECU reflash that the magic computer from M-B said was necessary (I was never able to find out what the reflash was supposed to do/take care of). Long story short - when I got the car back in two days - a 2 hour drive for me each direction - the SA told me 'bad news, the new valve body wouldn't adapt. They've tried every trick they know of." "Have to do it again." we are still waiting for the parts to arrive! No word for a week now!

DUTCH · #13 08-30-2007, 09:52 PM

Quote:

Originally Posted by Fourdiesel

Dutch
I had (am having) a similar problem with my GL320 CDI. Took it in 3 weeks ago to have a "sticking" upshift checked out. Turned out that with the instrumentation on the car the tech was able to confirm that the 4-5 upshift was occasionally not happening when it should (or when it was commanded to by me). Dealer ordered a new 'valve body' in, installed it and did a ECU reflash that the magic computer from M-B said was necessary (I was never able to find out what the reflash was supposed to do/take care of). Long story short - when I got the car back in two days - a 2 hour drive for me each direction - the SA told me 'bad news, the new valve body wouldn't adapt. They've tried every trick they know of." "Have to do it again." we are still waiting for the parts to arrive! No word for a week now!

The funny (not ha-ha) thing about my service invoice is that there are no parts listed, other than a slew of different nuts and bolts.

I've put about 1200 miles on it this week; and it seems (I hope) to have possibly adapted itself over the course of all the miles. It's shifting a whole lot smoother than when I picked it up from the dealer; and the hammer shift from 2->1 seems to have gone away. Time will tell.