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Forward collision avoidancePart report

2020 Mercedes-Benz GLC 300 Forward collision avoidance Problems

Complaints
6about this part
Share
9%of 70 total for the year
Median mileage
5,000miles
Trend
Not enough dataFewer than 15 complaints, too few for a reliable trend.

NHTSA recorded 6 complaints about the forward collision avoidance of the 2020 Mercedes-Benz GLC 300, 9% of the 70 complaints for this model year. Where a mileage was given, the median is 5,000 miles. 1 of these say a crash was involved, according to the filers. 1 recall campaign on record is filed under a similar system.

Fewer than 15 complaints name this part, so treat the figures as a rough indication only.

Example complaints

Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.

“While driving under an overpass the breaks activated abruptly and unexpectedly. We where going about 35 miles per hour and if it wasn't for the seat belts we would of hit the windshield. Luckily no one was following us up close.. It happened twice at the same spot where there is a shadow from the overpass (at same time of day)”

NHTSA complaint #11405472, filed 2021-03, 5,000 miles

“On August 15, 2025, I was driving my Mercedes-Benz GLC 300 4MATIC on the freeway under normal conditions. Without any warning lights, error messages, or prior signs of mechanical issues, the vehicle suddenly and completely lost power. The accelerator pedal became unresponsive and felt locked, and the vehicle came to an abrupt stop in the middle of an active freeway, in the second lane from the left. I had no ability to control or prevent the stoppage. This unexpected power loss directly led to a rear-end collision. …”

NHTSA complaint #11689240, filed 2025-09

“What component or system failed or malfunctioned, and is it available for inspection upon request? The Forward Collision Avoidance / Active Brake Assist (Automatic Emergency Braking) system failed by falsely identifying a non-existent threat and initiating uncommanded emergency stopping. The vehicle and its onboard control modules are fully available for physical and diagnostic inspection upon request. How was your safety or the safety of others put at risk? …”

NHTSA complaint #11760501, filed 2026-08

“SRS malfunction warning displayed on vehicles dashboard. Vehicle was diagnosed and displayed code B009749 Indicating: the crash sensor on the right hand side has a malfunction. There is an internal electrical fault.”

NHTSA complaint #11618239, filed 2024-10

“Self driving assist, adaptive cruise , emergency braking assist do not work. Taken to dealer three times , unable to correct. Returned to customer with out paperwork documenting repair of safety systems. Problems are still in I repaired state. Emergency braking system warning message has activated 15-20 times after receiving car back. Other existing problems are still on going as well. Requested District service Manager consult the situation and advise. Love car , want to have repaired . Looking to add additional GLC to household . Hope repair is possible . ????! …”

NHTSA complaint #11465447, filed 2022-05

Related recalls

Forward collision avoidance: other model years

YearComplaintsShare of year
2025319%
2024210%
2023713%
202235%
202134%
202069%
201833%
201744%

Other parts of the 2020 Mercedes-Benz GLC 300

Engine
22 complaintsOther or unknown
15 complaintsBack-over prevention (rear camera)
7 complaintsElectrical system
6 complaintsExterior lighting
5 complaintsSteering
5 complaintsFuel system
4 complaintsTransmission and drivetrain
4 complaintsBrakes
3 complaintsBody and structure
3 complaintsAir bags
2 complaintsVehicle speed control
2 complaints

← All problems reported for the 2020 Mercedes-Benz GLC 300

About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Nov 1, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.

To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology