Lurching at 9mph - Faulty CPS?
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From: Wisconsin
2008 CL65 AMG
Lurching at 9mph - Faulty CPS?
My 2008 CL65 has been lurching/stuttering when accelerating through first gear. It seems like the power cuts out at 9mph causing the car to lurch. It is totally smooth besides that, and this only happens when the engine is cold. After about 20 minutes of driving there are no more issues. I noticed this starting to happen about a year ago, and it has been getting progressively worse over the past year. Could this be a failing crankshaft position sensor? Why would this only happen when the car is not warmed up?
I brought the car to the dealership a month ago for the issue. They changed the transmission fluid and said the car runs fine. I drove it home, and once I started it the next morning, same thing. Lurching at 9mph!
Any thoughts on what this could be would be really appreciated! It's getting quite frustrating driving the car with the constant lurching
I brought the car to the dealership a month ago for the issue. They changed the transmission fluid and said the car runs fine. I drove it home, and once I started it the next morning, same thing. Lurching at 9mph!
Any thoughts on what this could be would be really appreciated! It's getting quite frustrating driving the car with the constant lurching
Thread Starter
Newbie
Joined: Apr 2024
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From: Wisconsin
2008 CL65 AMG
Interestingly enough, my hydraulic control module went bad about a month ago. At 9mph I would get "ESP and ABS inoperable" along with no power steering. I was hoping the module would also fix the lurching, but unfortunately that was not the case.
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Joined: Dec 2015
Posts: 94
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From: The boonies of Idaho
2002 Mercedes Benz SL500
My '07 does the same thing. A buddy of mine is a MB master tech at the local dealer, we drove the car, he had it happen to him, but couldn't figure out what the cause is. He ran it on the dealership Star system, there were no codes or any problems showing up there. We just agreed that I take it real easy when the car is cold, so the shudder is minimized. In my case, it reduces/stops within a couple of miles.
Just had a thought. You must run the trans in Sport (as do I). Try running it in Comfort and see if it still happens. I believe Comfort starts the car in second gear vs Sport which starts in first.
Let us know.
Michael
Just had a thought. You must run the trans in Sport (as do I). Try running it in Comfort and see if it still happens. I believe Comfort starts the car in second gear vs Sport which starts in first.
Let us know.
Michael
Last edited by PhoenixOp; Sep 29, 2025 at 09:42 AM.
Thread Starter
Newbie
Joined: Apr 2024
Posts: 12
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From: Wisconsin
2008 CL65 AMG
I do run it in sport for the most part. Last night I actually had it in comfort for a drive, and although the lurching was still present it was less severe. It's such a weird issue, since like you said once the car is warm it has no issues at all. Forgot to mention I also brought the car to an Indi Benz mechanic who did notice it but told me "yeah some cars do that".
I know I should just accept it, but its just so weird that this didn't used to happen, and has been getting progressively worse over the past year.
~BTW '07 Brabus CL600 is such a cool car!
I know I should just accept it, but its just so weird that this didn't used to happen, and has been getting progressively worse over the past year.
~BTW '07 Brabus CL600 is such a cool car!
Member
Joined: Dec 2015
Posts: 94
Likes: 13
From: The boonies of Idaho
2002 Mercedes Benz SL500
My only suggestion for longevity is take it really easy when you first start when cold. Try to minimize the shudder and it will (hopefully) not get worse. Those transmissions are ridiculous $ to rebuild/replace.
Thanks for the compliment. Yeah, it's cool, but a bit scary. Hit it about 3/4 throttle on a freeway on-ramp. By the time I cleared the on-ramp and was actually on the freeway I saw 145. The limiter is set to 211.
If I was still 26, this thing would be a hoot, but I'm 76, so my reflexes are on borrowed time...
Regards,
Michael
Thanks for the compliment. Yeah, it's cool, but a bit scary. Hit it about 3/4 throttle on a freeway on-ramp. By the time I cleared the on-ramp and was actually on the freeway I saw 145. The limiter is set to 211.
If I was still 26, this thing would be a hoot, but I'm 76, so my reflexes are on borrowed time...
Regards,
Michael
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Joined: Apr 2024
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From: Wisconsin
2008 CL65 AMG
Found a bulletin for the 722.6 transmission (attached).
I also found another post of someone with a 722.6 with a similar issue: "Stored DTC of P2108 - The internal electrical check of component Y3/6y2 (shift pressure control solenoid valve) has failed. Since it was electrical in nature, I removed the valve body and replaced the conductor plate and tested the solenoids."
Not sure if these trans issues cited above are related to my issue, but since the symptoms are pretty similar, I wanted to add them to the differential.
I also found another post of someone with a 722.6 with a similar issue: "Stored DTC of P2108 - The internal electrical check of component Y3/6y2 (shift pressure control solenoid valve) has failed. Since it was electrical in nature, I removed the valve body and replaced the conductor plate and tested the solenoids."
Not sure if these trans issues cited above are related to my issue, but since the symptoms are pretty similar, I wanted to add them to the differential.
