SL/R230: Throttle position Error
Thread Starter
Newbie
Joined: Oct 2024
Posts: 14
Likes: 1
SL600 R230 2004
Throttle position Error
Hi,
Almost flooring my gas pedal accelerating into the highway I lost power. Could not go above 100 km/h. No acceleration possible maybe just up to something like 2000 rpm. But almost not responding.
pulled in and checked the error codes. Found a
‘P0123 Throttle position (TP) switch A/accelerator pedal position (APP) switch A - high input’. After a restart I was able to accelerate again. For further context I have been experiencing some stalling events when the load is high at low speed. Eg. Starting on soft soil or maneuvering. Really doesn’t feel safe as it is almost impossible to stir without power on and loosing power when operating is scary too. Any advice for diagnostics and potential fixes would be much appreciated.
Almost flooring my gas pedal accelerating into the highway I lost power. Could not go above 100 km/h. No acceleration possible maybe just up to something like 2000 rpm. But almost not responding.
pulled in and checked the error codes. Found a
‘P0123 Throttle position (TP) switch A/accelerator pedal position (APP) switch A - high input’. After a restart I was able to accelerate again. For further context I have been experiencing some stalling events when the load is high at low speed. Eg. Starting on soft soil or maneuvering. Really doesn’t feel safe as it is almost impossible to stir without power on and loosing power when operating is scary too. Any advice for diagnostics and potential fixes would be much appreciated.
Super Member
Joined: Sep 2021
Posts: 541
Likes: 117
From: Ann Arbor, MI
2004 SL600
These cars are known to have accelerator pedals that fail after the many years we have had them. The pedal has two electrical rheostats in it; one raises the output voltage on circuit A while the other lowers the voltage on circuit B (or other way around). If the voltages go out of sync that indicates that one rheostat has gone bad and the car goes into limp mode. All electronic throttle pedal cars have 2 or 3 rheostats for safety - if it only had one rheostat and it failed it could cause immediate WOT.
I've seen a bunch of people here describing where to get a replacement pedal; not sure if available brand new, but definitely used ones on Ebay and perhaps shops that rebuild them.
First step might be to check that the electrical connector to the pedal is free of corrosion.
I've seen a bunch of people here describing where to get a replacement pedal; not sure if available brand new, but definitely used ones on Ebay and perhaps shops that rebuild them.
First step might be to check that the electrical connector to the pedal is free of corrosion.
Senior Member
Joined: May 2020
Posts: 454
Likes: 55
From: North Carolina, USA
2004 SL500AMG, 2003 SL500 USA
Get a new accelerator pedal. The dealer says the TPS (Throttle Position Sensor) is not serviceable. It is built into the pedal. It is fly by wire. So, there is no accelerator cable. Do a google search for accelerator pedal maybe by part number. Ebay usually has several used pedals and fit to your car can also show the part number. Shop around for great price (under $200).
MBWorld Fanatic!
Joined: Mar 2018
Posts: 1,442
Likes: 260
From: Netherlands
2005 R 230 SL350 (M112 3.7). Sold the 1966 W113 230SL recently
Check price for new original pedal - you might be pleasantly surprised. Someone put a coin under/in the pedal to avoid the 100% WOT position, as that is where the malfunction starts happening.
