Pre safe functions limited loss of power
02-19-2023, 10:41 PM
#1
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Thread Starter
Pre safe functions limited loss of power
Hey guys,
I’ve read a lot of people had a similar issue with pre safe being limited and loss of power on mersades I just want to see if I’m diagnosing the problem correctly or if anyone has any helpful insight for me , I’m freaking scared to drive on the highway now. My hands are sweaty and this is not a great experience. I just wanted to see if it might be just a faulty, Excelerator pedal or there’s some deeper insight that someone more experience than me would know just some back context I had a similar issue, but I would still have power if you look in my previous post, which was just a wheel angle sensor that I forgot to turn on, I have a video attached of what the car was doing. Basically I was driving uphill most of the time this happens you just feel like a little jolt and the Excelerator is not giving you any power to your car and then this message pops up which is pretty scary. I have the video attached below if anyone has any helpful insight , that would be amazing. Thanks.
just to add a little bit more, the car itself is revving when in park I’m not actually pressing the Excelerator
https://youtube.com/shorts/OL4UTREI440?feature=share
I’ve read a lot of people had a similar issue with pre safe being limited and loss of power on mersades I just want to see if I’m diagnosing the problem correctly or if anyone has any helpful insight for me , I’m freaking scared to drive on the highway now. My hands are sweaty and this is not a great experience. I just wanted to see if it might be just a faulty, Excelerator pedal or there’s some deeper insight that someone more experience than me would know just some back context I had a similar issue, but I would still have power if you look in my previous post, which was just a wheel angle sensor that I forgot to turn on, I have a video attached of what the car was doing. Basically I was driving uphill most of the time this happens you just feel like a little jolt and the Excelerator is not giving you any power to your car and then this message pops up which is pretty scary. I have the video attached below if anyone has any helpful insight , that would be amazing. Thanks.
just to add a little bit more, the car itself is revving when in park I’m not actually pressing the Excelerator
https://youtube.com/shorts/OL4UTREI440?feature=share
02-19-2023, 11:39 PM
#2
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Join Date: May 2018
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2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
Try reading this and get a decent bi-directional scanner to see trouble codes which can lead to the culprit ...eventually.
https://mechanicask.com/pre-safe-functions-limited/
The bottom line is this :
Pre-Safe is a complex coordination of many modules/sensors working together to manage the task programmed into it by the engineers.
This is the problem : coordination of many modules/sensors working together
I call it a problem because it is a bi.tch to troubleshoot when you do not have a decent bi-directional scanner and decent knowledge how all these thing works in harmony.
Good luck
ADD : If for some reason the pre-safe system assumed obstruction is ahead , while in actual fact it is a lump of dirt falsely read as a target by the radar sensor,
the system can do what you are experiencing now, power cut.
https://mechanicask.com/pre-safe-functions-limited/
The bottom line is this :
Pre-Safe is a complex coordination of many modules/sensors working together to manage the task programmed into it by the engineers.
This is the problem : coordination of many modules/sensors working together
I call it a problem because it is a bi.tch to troubleshoot when you do not have a decent bi-directional scanner and decent knowledge how all these thing works in harmony.
Good luck
ADD : If for some reason the pre-safe system assumed obstruction is ahead , while in actual fact it is a lump of dirt falsely read as a target by the radar sensor,
the system can do what you are experiencing now, power cut.
Last edited by S-Prihadi; 02-19-2023 at 11:42 PM.
