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I have a stock 2014 E63s with about 60K miles on the clock. I've had random but continuing issues where the car dies at a stop. I have SDConnect with Xentry, and have pulled codes several times. The only thing the pops up is a B1F8D14, "The lower sensor of the rear switching module has a malfunction. There is a short circuit to ground or an open
circuit."
Any ideas of what might be causing this? Also anyone know what the "lower sensor of the rear switching module" is? Seems odd that the car doesn't throw a code when the car dies unexpectedly.
i would professionally check rail pressure after getting a very good scan
First, thanks for responding. Help me understand a "very good scan". Is there something better than Star, or are you referring to a scan related directly to the rail pressure?
The only thing the pops up is a B1F8D14, "The lower sensor of the rear switching module has a malfunction. There is a short circuit to ground or an open circuit."
Hello Joe, you may want to look into the sensor system for the trunk lid opening/closing. The 2 sensors are essentially wires that connect to the switching module. The attached WIS article AR80.61-P-0012EW may be of assistance to you. It calls for the rear bumper removal, but you may be able to get away without it. Hope this helps.
Hello Joe, you may want to look into the sensor system for the trunk lid opening/closing. The 2 sensors are essentially wires that connect to the switching module. The attached WIS article AR80.61-P-0012EW may be of assistance to you. It calls for the rear bumper removal, but you may be able to get away without it. Hope this helps.
Thanks for your response! What leads you in that direction? Don't mind bumper removal, but would like to understand the need first.
@Valvestud With a nearly 8 year old vehicle, what is your opinion on changing the battery? And if your vehicle at one time had start/stop, it also has either a capacitor or auxiliary battery. What do you think about replacing the capacitor or aux battery?
@Valvestud With a nearly 8 year old vehicle, what is your opinion on changing the battery? And if your vehicle at one time had start/stop, it also has either a capacitor or auxiliary battery. What do you think about replacing the capacitor or aux battery?
Thank for the reply. Both batteries are new. Not sure what "capacitor" you're referring to. Can you elaborate?
I think it's the C-Class that uses a capacitor, rather than an auxilliary battery, for the eco start/stop function. If you have replaced both batteries in your vehicle, that box is checked. The search function will bring up references to the capacitor.
I think it's the C-Class that uses a capacitor, rather than an auxilliary battery, for the eco start/stop function. If you have replaced both batteries in your vehicle, that box is checked. The search function will bring up references to the capacitor.
There is a "battery backup relay" that might be related to the issue. Was hoping to get more user experience data before going down the road of replacing parts one at a time.
Also may be fuel related as suggested by another member.
Sorry to go off topic . But the eco stop/start can be permanently turned off ? through star etc i'm assuming
.Just saw the Vediamo note - got it
This can be accomplished very quickly and easily with our OBD programmer.
You can program your vehicle to remember what the last eco start/stop setting you have it on (On or Off).
Check coverages HERE
Hello Joe, you may want to look into the sensor system for the trunk lid opening/closing. The 2 sensors are essentially wires that connect to the switching module. The attached WIS article AR80.61-P-0012EW may be of assistance to you. It calls for the rear bumper removal, but you may be able to get away without it. Hope this helps.
So during a session on Xentry today with Peter (BenzNinja), we did a deep dive into the error related to the ECo Start/Stop fault that relates to the bumper sensor. The faults relates to the up/down sensors not responding accurately. Still doesn't seem likely this is killing the car, but I will investigate anyway to fix.
06-04-2021, 04:17 PM
