SL/R230: Feature, Issue, or problem between my ears?
Thread Starter
Newbie
Joined: Aug 2014
Posts: 10
Likes: 0
From: SW Pennsylvania
SL600
Feature, Issue, or problem between my ears?
I recently picked up a 2004 SL600 with 60K miles in what I think was really good condition and well cared for.
On three different occasions it has however gone into what I can only call a limp mode. No acceleration, barely able maintain even 40 MPH but still running smooth without missing a beat. Clearly it was not getting fuel.
Stop, shut it off, start it up again and all is well. The Star Diagnostics doesn't show any problems. (I need to check this again) Nothing unusual on the dash...
So I start thinking about it. Seems to only happen after I just nail the throttle with authority (when you least want to loose power). Once while trying to merge into traffic entering a freeway was flat scary.
So I try some simple experiments. Turn ESP off and rather than going to limp mode you can light up tires
.
Role the throttle on like a normal person and it just accelerates like a monster.
Not sure if it has anything to do with the C/S setting but it may have accidentally been in the Comfort mode.
Any ideas?
On three different occasions it has however gone into what I can only call a limp mode. No acceleration, barely able maintain even 40 MPH but still running smooth without missing a beat. Clearly it was not getting fuel.
Stop, shut it off, start it up again and all is well. The Star Diagnostics doesn't show any problems. (I need to check this again) Nothing unusual on the dash...
So I start thinking about it. Seems to only happen after I just nail the throttle with authority (when you least want to loose power). Once while trying to merge into traffic entering a freeway was flat scary.
So I try some simple experiments. Turn ESP off and rather than going to limp mode you can light up tires
.Role the throttle on like a normal person and it just accelerates like a monster.
Not sure if it has anything to do with the C/S setting but it may have accidentally been in the Comfort mode.
Any ideas?
Junior Member
Joined: Aug 2013
Posts: 33
Likes: 0
From: Central NH
C300 4MATIC And formerly 73 450SL
I doubt this even makes sense. But just thought I would mention my (somewhat similar) experience.
Accelerating a little aggressively to pull into a line of traffic. All of a sudden the car shuts down and a red warning on the DIC. ESP Malfunction...Visit workshop. Pull over and shut off ignition. Restart and message goes away, and everything runs normal again. EXCEPT...Check Engine Light is displayed, now.
So next day, I take it to my son's automotive shop. He reads codes. And it shows MAF (Mass Air Flow) sensor is defective. He resets codes and CEL returns again, after a minute or so. Does is again, and same result.
He changes the MAF, and all is well.
I don't know if this could be similar to your issue, or not. But I do think that somehow the ESP system is related to the MAF, and/or the BAS (brake assist system) and engine vacuum system.
I have also experienced cases where a vacuum leak has occurred and there has been no CEL displayed.
Hope this can help you.
Accelerating a little aggressively to pull into a line of traffic. All of a sudden the car shuts down and a red warning on the DIC. ESP Malfunction...Visit workshop. Pull over and shut off ignition. Restart and message goes away, and everything runs normal again. EXCEPT...Check Engine Light is displayed, now.
So next day, I take it to my son's automotive shop. He reads codes. And it shows MAF (Mass Air Flow) sensor is defective. He resets codes and CEL returns again, after a minute or so. Does is again, and same result.
He changes the MAF, and all is well.
I don't know if this could be similar to your issue, or not. But I do think that somehow the ESP system is related to the MAF, and/or the BAS (brake assist system) and engine vacuum system.
I have also experienced cases where a vacuum leak has occurred and there has been no CEL displayed.
Hope this can help you.
Newbie
Joined: Jul 2014
Posts: 10
Likes: 0
2007 SL550
Oldkneedragger
Had similar issue with my 07 SL550. Twice the Cruise and the ESP kicked offline and left me in limp mode after I nailed it to pass someone and RPM's shot up. A reset/restart would clear it up. Replaced starter battery and haven't had the problem since.
I was having a problem where the car was hard to start (slow to crank) after being up to temp. Cold start was always fine. Was wondering if tolerances were tight on the voltage monitoring and having a slightly low starter battery and then RPM increase raised generator output a tad and this caused just big enough delta in voltages to trip these systems. All I know is that I haven't seen the problem since I put the new battery in.
I don't even know if your model has the same config with the two batteries, but if you do: check the voltage on the starter battery static, and then keep the leads on and read the lowest value while someone cranks it. This will tell you if it is good.
Good Luck
Rich
Had similar issue with my 07 SL550. Twice the Cruise and the ESP kicked offline and left me in limp mode after I nailed it to pass someone and RPM's shot up. A reset/restart would clear it up. Replaced starter battery and haven't had the problem since.
I was having a problem where the car was hard to start (slow to crank) after being up to temp. Cold start was always fine. Was wondering if tolerances were tight on the voltage monitoring and having a slightly low starter battery and then RPM increase raised generator output a tad and this caused just big enough delta in voltages to trip these systems. All I know is that I haven't seen the problem since I put the new battery in.
I don't even know if your model has the same config with the two batteries, but if you do: check the voltage on the starter battery static, and then keep the leads on and read the lowest value while someone cranks it. This will tell you if it is good.
Good Luck
Rich
Last edited by El Gringo; Sep 27, 2014 at 09:34 AM.
