SL55/63/65/R230 AMG: Replaced accel pedal assembly/TPS, still enters "Limp Mode" under hard acceleration
Thread Starter
Junior Member
Joined: Jun 2006
Posts: 37
Likes: 0
From: Atlanta
'12 Cayenne Turbo, '12 GL450, '03 SL55, '89 560SL,
Replaced accel pedal assembly/TPS, still enters "Limp Mode" under hard acceleration
2003 SL55, 90k miles.
The car will randomly enter what I call "Limp Mode" when the horsepower drops from 500 hp down to seemingly 100 hp. It still accelerates, but just barely. The kind of acceleration where going downhill would help. I can initiate this problem like clockwork- get on the highway, gun the motor with brief sprints of hard acceleration for five minutes, and it will certainly occur. However, it also randomly occurs while just cruising along at US-highway speeds of 80 mph.
After searching this forum, I decided to do a complete accelerator pedal assembly replacement, including the throttle position sensor (TPS). That hasn't fixed the problem; it still occurs a couple times a week during normal highway driving. What's the next step?
Thanks SO MUCH, everyone!
The car will randomly enter what I call "Limp Mode" when the horsepower drops from 500 hp down to seemingly 100 hp. It still accelerates, but just barely. The kind of acceleration where going downhill would help. I can initiate this problem like clockwork- get on the highway, gun the motor with brief sprints of hard acceleration for five minutes, and it will certainly occur. However, it also randomly occurs while just cruising along at US-highway speeds of 80 mph.
After searching this forum, I decided to do a complete accelerator pedal assembly replacement, including the throttle position sensor (TPS). That hasn't fixed the problem; it still occurs a couple times a week during normal highway driving. What's the next step?
Thanks SO MUCH, everyone!
Last edited by skiendog; May 21, 2018 at 09:29 AM.
Thread Starter
Junior Member
Joined: Jun 2006
Posts: 37
Likes: 0
From: Atlanta
'12 Cayenne Turbo, '12 GL450, '03 SL55, '89 560SL,
I think I have the 010 currently, but I will verify. Thanks.
MBWorld Fanatic!
Joined: Jul 2010
Posts: 4,359
Likes: 229
SL55, S500
Only way to fix the pedal temporarily is restart the car.
You would have a code too and a check engine(sometimes)
which would lead to think it’s not the pedal because you said you can resolve it without a restart.
You would have a code too and a check engine(sometimes)
which would lead to think it’s not the pedal because you said you can resolve it without a restart.
Member
Joined: Feb 2018
Posts: 160
Likes: 32
2005 SL55 Completely Built Motor
I know its been quite hot down in ATL lately so it could be your intercooler pump not performing to its specs. Which would also be the reason why its only do it once in awhile. New pump is only about $100 so its an easy thing to try.
Otherwise you may have to try to get the car to keep recreating the problem and report back here or let a local Indy shop look at it.
Otherwise you may have to try to get the car to keep recreating the problem and report back here or let a local Indy shop look at it.
