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Hello,
My 2017 GLC300 4Matic is displaying the “Collision Prevention Assist Plus Inoperative” error message each time I start my vehicle until I press “OK”…. my vehicle is also displaying the “Stop Vehicle Leave Engine Running” error message at separate times; I read somewhere that the collision prevention inoperative message could be due to the battery needing to be replaced, is this true? Because the low battery message doesn’t always seem to show up, so I am a little confused as to how they could relate if so. Please see the attached photos of the messages and if anyone has any thoughts/opinions please comment below. Thanks : )
Not sure if the two are related, but I notice that its 16F in that second picture. If you have never replaced your battery, its 5 years old now and thats when 12V batteries tend to start dying. The cold weather could have pushed it over the edge.
If you're no longer under warranty, I'd start by going to an autozone or similar chain that provides free battery diagnostics. If battery needs replacing, then do that and see if the other issue comes back.
Hello,My 2017 GLC300 4Matic is displaying the “Collision Prevention Assist Plus Inoperative” error message each time I start my vehicle until I press “OK”…. my vehicle is also displaying the “Stop Vehicle Leave Engine Running” error message at separate times; I read somewhere that the collision prevention inoperative message could be due to the battery needing to be replaced, is this true? Because the low battery message doesn’t always seem to show up, so I am a little confused as to how they could relate if so. Please see the attached photos of the messages and if anyone has any thoughts/opinions please comment below. Thanks : )
I have had the collision message for over a year.
I had engine running message only a few times when my battery so much drained.
my auto stop start didn't work months ago, so i replaced my AGM battery, then auto stop fixed.
But still i have collision message on every engine starting.
so new battery won't fix the collision message for sure.
let me know if you find how to fix collision message.
These errors can usually be traced to unstable radar modules.
Radar modules use mixed Analog/Digital technologies. They can fail either because of rain intrusion or wild voltage swings.
Once a radar has been swamped is compromised, it routinely prevents the car from entering low power sleep-mode... battery then drains while parked.
Best way to know exactly where you stand is to scan the car for list of faults or book a MBenz specialist visit.
Also consider using a CTEK Charger to float your battery. These cars have many ways to drain system battery while driving or while parked. Float charging prevents high current and easily extends battery life.
Hope this all helped you.
Last edited by CaliBenzDriver; Jan 19, 2023 at 06:00 AM.
Hello,
Check you main battery, had the same issue battery was failing. Also while you are changing your battery also replace your voltage regulator they will usually go bad and cause seme error messages to show up.
Went in to have my oil change and what not done. Whilst it was there I had the battery replaced. The service advisor agreed with me when I said the collision prevention assist inoperative error could have been due to the battery. $599 later with the new battery, it still is popping up. The service advisors had said it was due to a damaged front bumper… I was confused because I don’t have a damaged bumper? I had him send a photo and he sent a photo of my modification on the front of the car which was coming off because it was only on with tape. After I told him it was a modification because my car is a GLC300 4Matic with aesthetic GLC43 mods, he told me to take it off because it could have been blocking a sensor and to drive the car around for a few days for the radar to recalibrate; and if it keeps saying it then it could need a radar/sensor module replaced. I did what he said and took it off, drove around for a few days and the error is still popping up. The service advisor said he could have someone take a look at it for another $200, I did not have that happen.
Went in to have my oil change and what not done. Whilst it was there I had the battery replaced. The service advisor agreed with me when I said the collision prevention assist inoperative error could have been due to the battery. $599 later with the new battery, it still is popping up. The service advisors had said it was due to a damaged front bumper… I was confused because I don’t have a damaged bumper? I had him send a photo and he sent a photo of my modification on the front of the car which was coming off because it was only on with tape. After I told him it was a modification because my car is a GLC300 4Matic with aesthetic GLC43 mods, he told me to take it off because it could have been blocking a sensor and to drive the car around for a few days for the radar to recalibrate; and if it keeps saying it then it could need a radar/sensor module replaced. I did what he said and took it off, drove around for a few days and the error is still popping up. The service advisor said he could have someone take a look at it for another $200, I did not have that happen.
The stealership advisor success story.I told, my new battery didn't fix the collision error.Costco canada's Energizer AGM battery was CDN$300.
Anyway thank you for update, please let us know if you eventually fix the error. I live with the message for 1 year now, but pressing ok button is annoying on every engine startups.
Last edited by sn202020; Feb 16, 2023 at 11:16 AM.
I’ve seen this issue pop up quite a bit with Mercedes models. The warning doesn’t always mean your battery is bad, it can also be a sign that the radar sensor used for the Collision Prevention Assist has failed. If your battery/alternator test fine, then chances are the sensor is at fault. I’d suggest taking a look at this part listing I found: xenons4u.co.uk/a0009054907-radar-sensor.html. It gives some helpful details about what the part does and why calibration is important after replacement.
Before spending money, I’d suggest:
Test your battery and alternator.
Check wiring to the radar sensor.
If both are fine, consider replacing the sensor.
Keep in mind that fitting a new sensor usually requires calibration and coding afterwards.
Last edited by flynnthomas78; Oct 3, 2025 at 07:30 AM.
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