Gear downshift - jerking
#1
Gear downshift - jerking
hello,
wondering if anyone encounter this problem, not sure if it is normal?
everytime when there is downshift in gear the car will jerk badly.
especially during traffic congestion moving at a slow pace.
when I press on the accelerator and suddenly the car in front brake, which i have to let go the accelerator, the car will jerk.
when to the service center and they said that they have reprogram (i actually dont know what they program) now the situation seems to be worst than before.
and at times it will not jerk but i can feel the engine vibrates.
the car is just 6 months old
wondering if anyone encounter this problem, not sure if it is normal?
everytime when there is downshift in gear the car will jerk badly.
especially during traffic congestion moving at a slow pace.
when I press on the accelerator and suddenly the car in front brake, which i have to let go the accelerator, the car will jerk.
when to the service center and they said that they have reprogram (i actually dont know what they program) now the situation seems to be worst than before.
and at times it will not jerk but i can feel the engine vibrates.
the car is just 6 months old
#2
Super Moderator
This is a fairly common problem with the 722.9 transmission. Make sure that the TCU (transmission control unit) has the latest software flash designed to fix this.
Severe jerks under power on the way up through the gears usually spell valve body/electrohydraulic unit problems.
Changedown jerks & heavy trailing throttle jerks when you lift off the gas quickly are usually software related & you sometimes catch out the TC clutches as they are trying to engage.
Good luck!
Severe jerks under power on the way up through the gears usually spell valve body/electrohydraulic unit problems.
Changedown jerks & heavy trailing throttle jerks when you lift off the gas quickly are usually software related & you sometimes catch out the TC clutches as they are trying to engage.
Good luck!
#5
Super Member
I described it to my SA like this... "It feels like the car is being rear ended on down shifts..."
Got ripped a new one for a transmission diagnosis/reprogram and flush... (SA agreed to a free detail... HAH, they'll run it through the car wash and MAYBE ,if they even decide to go this far, give it some fresh swirls with a power buffer)
Funny how the dealership that I purchased from always offers to look at things like this for free, and then call with an initial opinion and estimate.
The other clowns are too happy to rack up a fat list of $400 "a la carte" service items to fix whatever your problem may be and get your signature on that piece of paper so they can bill you. Go figure, almost every time I ask them if they are sure that [xxxx repair] is what needs to be fixed they answer "well we can't be sure until we get in there" [read: even if it doesn't we're going to bill you]. We agree to discuss it when my car is in the shop and the tech has had at least a moment with the car...
And then what happens next? Your invoice gets dropped in a box, the tech picks it up and performs said service completely oblivious to the the fact I want to talk to the SA before work is done. You come back pick up your car, and your SA is STILL not sure if your car is fixed....
I'll have to find that out later... on the road somewhere... hopefully not in the middle of bumble**** or severe weather.
Mercedes Benz service is a laugh (outside of the showroom).
Got ripped a new one for a transmission diagnosis/reprogram and flush... (SA agreed to a free detail... HAH, they'll run it through the car wash and MAYBE ,if they even decide to go this far, give it some fresh swirls with a power buffer)
Funny how the dealership that I purchased from always offers to look at things like this for free, and then call with an initial opinion and estimate.
The other clowns are too happy to rack up a fat list of $400 "a la carte" service items to fix whatever your problem may be and get your signature on that piece of paper so they can bill you. Go figure, almost every time I ask them if they are sure that [xxxx repair] is what needs to be fixed they answer "well we can't be sure until we get in there" [read: even if it doesn't we're going to bill you]. We agree to discuss it when my car is in the shop and the tech has had at least a moment with the car...
And then what happens next? Your invoice gets dropped in a box, the tech picks it up and performs said service completely oblivious to the the fact I want to talk to the SA before work is done. You come back pick up your car, and your SA is STILL not sure if your car is fixed....
I'll have to find that out later... on the road somewhere... hopefully not in the middle of bumble**** or severe weather.
Mercedes Benz service is a laugh (outside of the showroom).
#6
Member
Join Date: Oct 2008
Location: San Diego, CA
Posts: 200
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2016 C450 AMG
I described it to my SA like this... "It feels like the car is being rear ended on down shifts..."
Got ripped a new one for a transmission diagnosis/reprogram and flush... (SA agreed to a free detail... HAH, they'll run it through the car wash and MAYBE ,if they even decide to go this far, give it some fresh swirls with a power buffer)
Funny how the dealership that I purchased from always offers to look at things like this for free, and then call with an initial opinion and estimate.
The other clowns are too happy to rack up a fat list of $400 "a la carte" service items to fix whatever your problem may be and get your signature on that piece of paper so they can bill you. Go figure, almost every time I ask them if they are sure that [xxxx repair] is what needs to be fixed they answer "well we can't be sure until we get in there" [read: even if it doesn't we're going to bill you]. We agree to discuss it when my car is in the shop and the tech has had at least a moment with the car...
And then what happens next? Your invoice gets dropped in a box, the tech picks it up and performs said service completely oblivious to the the fact I want to talk to the SA before work is done. You come back pick up your car, and your SA is STILL not sure if your car is fixed....
I'll have to find that out later... on the road somewhere... hopefully not in the middle of bumble**** or severe weather.
Mercedes Benz service is a laugh (outside of the showroom).
Got ripped a new one for a transmission diagnosis/reprogram and flush... (SA agreed to a free detail... HAH, they'll run it through the car wash and MAYBE ,if they even decide to go this far, give it some fresh swirls with a power buffer)
Funny how the dealership that I purchased from always offers to look at things like this for free, and then call with an initial opinion and estimate.
The other clowns are too happy to rack up a fat list of $400 "a la carte" service items to fix whatever your problem may be and get your signature on that piece of paper so they can bill you. Go figure, almost every time I ask them if they are sure that [xxxx repair] is what needs to be fixed they answer "well we can't be sure until we get in there" [read: even if it doesn't we're going to bill you]. We agree to discuss it when my car is in the shop and the tech has had at least a moment with the car...
And then what happens next? Your invoice gets dropped in a box, the tech picks it up and performs said service completely oblivious to the the fact I want to talk to the SA before work is done. You come back pick up your car, and your SA is STILL not sure if your car is fixed....
I'll have to find that out later... on the road somewhere... hopefully not in the middle of bumble**** or severe weather.
Mercedes Benz service is a laugh (outside of the showroom).
#7
Senior Member
Join Date: Jan 2009
Location: Philippines/California, USA
Posts: 360
Likes: 0
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W204 C280
I had the same problem when I first got my car. Had my car reprogrammed. It went away. Though a year later it came back, had it reprogrammed again, it went away. Another year later, the problem came back and again, after reprogramming, it went away. Looks like reprogramming should be part of the yearly maintenance program? haha