Strange transmission shift from 1st to 2nd gear
I have a 2003 C230 kompressor sedan. I'm having a weird problem with my transmission. Its automatic transmission. If I'm accelerating smoothly, when it shifts from 1st to 2nd gear, the car jerks, like its pushed forward all of a sudden, and then everything goes back to normal. If I press on the pedal and accelerate fast, this doesn't happen. All other shifts are normal, its only the shift from 1st to 2nd gear when accelerating slowly. Any ideas what might be causing this?
Thanks in advance.

I have a 2003 C230 kompressor sedan. I'm having a weird problem with my transmission. Its automatic transmission. If I'm accelerating smoothly, when it shifts from 1st to 2nd gear, the car jerks, like its pushed forward all of a sudden, and then everything goes back to normal. If I press on the pedal and accelerate fast, this doesn't happen. All other shifts are normal, its only the shift from 1st to 2nd gear when accelerating slowly. Any ideas what might be causing this?
Thanks in advance.
I dont believe my car has done a transmission flush or change in oil or filter, that could be the problem. The jerk is definately there only from 1st to 2nd.




The dealer reflashed the auto-module with the "latest version" (this was in 2006) which didn't solve the problem. One just learns to live with it. Not sure about your problem, but mine generally happens if I'm at high RPM right before/after the switch. For example, it happens often if I'm accelerating hard from 1st to 2nd, or I use engine braking going from 3rd into 2nd.
Last edited by slammer111; Apr 15, 2020 at 04:24 AM.
)I only have 20K miles.
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)I only have 20K miles.
Last edited by Glyn M Ruck; Mar 22, 2009 at 07:50 PM.
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I still have warranty till November i'll take it in. Also I still get this weird noise underneath the car. Lately it has gotten loud. It sounds like its ticking (tic tic tic). The ticking sounds use to be once in a while and now it's common. I remember Glyn you said that it might be the cat and it does seem like it because it is coming from somewhere in the middle.
Edit
The other day I met up with my friends at a coffee shop. When we were leaving I was making a right I didn't see a car was coming so I hit the gas hard so the car doesn't hit me. The next day my friends were asking me if I removed the resonator because a it sounded weird when I accelerated. If a cat does get messed up does it make ticking noise?
Thanks Again Glyn
Last edited by W203E35; Mar 22, 2009 at 06:42 PM.

Yes the Cat can tick - Read PAPete's thread in this regard. How many speed bumps do you ride over? Speed bumps or severe potholes are Cat killers when the catalyst is incandescent. Usually a piece of the honeycomb breaks off.
Thanks for your time and help Glyn I really appreciate it.
Last edited by W203E35; Mar 22, 2009 at 08:48 PM.
Is there any way to check the tranny fluid without a dipstick? Can someone tell me the part # for a tranny dipstick so I can order one (also the part # oil dipstick if possible - I'll just order both at the same time)?

A jerk on change up from 1st to 2nd would be something else like the TCU not indicating to the ECU to retard timing at the moment of change up or a solenoid or valve body malfunction.
If oil, filters, levels etc are in good condition my first move would be to reflash the tranny software.
The gear ratios present here are always going to amplify shift shock issues.
I just got to work. 6:00 AM USA (Pacific). I was on the freeway driving and there was construction on the freeway. I slowed down to change my lane and when I accelerated (Not fast just regular accelaration) my car jerked (downshifted) very hard. I definetly need to take my car to the dealer.
P.S. I still have the 1st to 2nd jerk but it comes and goes. But the most I feel is when it downshifts from 2nd to 1st.
I just got to work. 6:00 AM USA (Pacific). I was on the freeway driving and there was construction on the freeway. I slowed down to change my lane and when I accelerated (Not fast just regular accelaration) my car jerked (downshifted) very hard. I definetly need to take my car to the dealer.
P.S. I still have the 1st to 2nd jerk but it comes and goes. But the most I feel is when it downshifts from 2nd to 1st.
A little more that I wanted to add (maybe it will help out to get to the bottom of the problem for our fellow members who don't have warranty)
I was headed home (left a little early from work) and I noticed something else. Not only was the 1st to 2nd jerking but I felt the car was less responsive than it use to be. I believe it's a computer issue. I feel like the computer (proof that i'm a newb saying the word computer) isn't switching the gears correctly. So first it started with the 1st and 2nd gears jerking, in the morning on the free way slowing down then accelerating slowly felt like gear slipped and now it feels like the whole transmission even the throttle is lagging a bit. I press the gas pedal and there is a second lag.
Also I want to add that I have this rattling (sort of like a vibration) noise underneath the car and these couple of days the car sounded wierd. Which now comfirms Glyn's suggestion that it's the cat.
Thank You Glyn

I don't mean to sound like i'm attacking anyone or sound like a smart a$$ (just curious) does the transmission software get messed up or corrupt on it's own that's why it needs to be reflashed?
Last edited by W203E35; Mar 24, 2009 at 04:53 PM.

You might have some throttle switch problems but more likely a piece of Cat honeycomb moving around & partially blocking the exhaust.
BTW - you are most welcome to question me - then we all learn. Makes me get off my butt & do more research. I make many mistakes along with the rest of us. We're unfortunately not infallible. All I try and do is learn something new every day of my life.
Last edited by Glyn M Ruck; Mar 24, 2009 at 06:45 PM.




You can't check the level.
And it's also true, there was a software update to correct jerkiness.
So, do either or both as needed.
You might have some throttle switch problems but more likely a piece of Cat honeycomb moving around & partially blocking the exhaust.
BTW - you are most welcome to question me - then we all learn. Makes me get off my butt & do more research. I make many mistakes along with the rest of us. We're unfortunately not infallible. All I try and do is learn something new every day of my life.
Thanks Guys
Learning something new everyday.

The only field I am good at is computers. So if you guys need help with computers or software let me know

I dont know any other way to show how much I appreciate you guys taking the time to help me.
Thanks Again
Edit
C230 Sport Coupe, Thanks for the info on the 722.9 Transmission.
Glyn, thanks for your countless help with my newbish questions.
I thought I should give back to the community with my findings.
I found these on forums. It seems like people are having problems with the 722.9 transmissions.
Had the DTB done yesterday to fix the acceleration lag; and I can see only a miniscule, if any, improvement in the lag. I also ended up with an even harder 2->1 downshift out of the deal.
There is new software in the works to fix the hard 2->1 downshift in all 722.9 transmissions
In the mean time there is a new ATF 4134 (spec 236.14) P/N: 001-989-68-03-10 that is being recommended for all 722.9 transmissions. It it is supposed to run cooler, which might be a help for that hard 2->1 downshift; since on mine, it always seems to be worse when the weather and engine/transmission are hotter.
Price on the old ATF 3353 (spec 236.12) was/is $15.00/liter. The new ATF 4134 (spec 236.14) is priced at $32.50/liter.
Schedule to change at 40,000 miles.
Important info on changing Transmission Oil
The impossible part of trying to follow the WIS is that you must first refill 1 liter more than you drained. Then you must run the engine and cycle through P-R-N-D, etc. Then, with the engine idling in P, you must allow any excess oil to drain with the transmission at 40°C. The big problem is that, by this time, the transmission is already much hotter (~70°C); and there is a very big warning about the fact that too much will drain out, if the temperature is more than 40°C.
The only way to do this would be to refill and do the gear cycle. Then shut it off and allow it to cool over night. The next morning you could hook up the STAR, start the engine, remove the drain plug and allow it to drain while warming up. When it hits 40°C, close the plug and be done with it.
The engineer who designed this system must have been doing some very bad drugs when he did it. He certainly never worked on a shop floor or did this procedure himself.
In connection with my thread in the engine oil section, it seems like Mercedes is reducing the service intervals for their cars. From the 2009 maintenance manual, I noticed that Mercedes now requires a transmission fluid and filter change every 4 years or 40,000 miles, whichever comes first on all of their vehicles.
I guess the new 722.9 7-speed automatics need more frequent maintenance than its predecessors. The constant shifting must be putting some serious stress on the fluid.
Last edited by W203E35; Mar 24, 2009 at 07:34 PM.


Last edited by Glyn M Ruck; Mar 25, 2009 at 08:13 PM.



