Owners report two main brake problems on the 2015 Grand Cherokee: erratic automatic emergency braking and forward collision warning systems that engage on clear roads, and conventional brake failures that leave owners without stopping power.
The automatic systems activate without obstacles present—during lane changes, on highways with clear roads ahead, around stationary objects like jersey barriers, and during normal adaptive cruise control use. Activation is violent: full brake engagement, audible alarms, and "BRAKE BRAKE BRAKE" warnings. Three owners report nearly being rear-ended as a result. One owner was in service 51 of 103 days of ownership; dealers said the system worked as designed. Another experienced activation at 70 mph with an empty road ahead. Multiple owners report this happening repeatedly over months or years, yet dealers cannot reproduce the failure.
Conventional brake failure appears at various mileages. One owner pressed the brakes, released, then braked again when a car ahead stopped abruptly—the second application produced no braking response, resulting in a collision. Another experienced brake failure in light rain after several days of ownership. An ABS warning light was logged after one failure event.
A third category includes a brake booster failure at 18,000 miles with grinding noise and stuck pedal, a park-position failure allowing the vehicle to roll downhill multiple times, unintended acceleration against full brake pedal pressure, and left-side brake grabbing with vibration. Owners also report delays obtaining recall parts for left front calipers; one waited over three months with conflicting dealer information.
Failure modes owners describe
Forward Collision/Automatic Emergency Braking System Engages Erratically
The adaptive cruise control, forward collision warning, and automatic emergency braking sensors activate the brakes without valid obstacles present. Owners report the system slams on brakes with audible alerts during normal driving on clear roads, sometimes multiple times in the same drive. Dealers tested vehicles and claimed systems work as designed, but owners report this behavior is not replicated in loaner vehicles or in comparable equipped vehicles.
When: Various mileages reported; complaints from early ownership through 3+ years of ownership. One incident at approximately 6,999 miles; another at 15,000 miles; one owner experienced this for three years.
Symptoms owners cite: Sudden, unexpected full braking with no obstacle in front of vehicle; System activates during clear road conditions; System activates during lane changes with no traffic hazard; System activates when adaptive cruise control is engaged; System activates around jersey barriers and stationary objects to the side; Audible bells/alarms and 'BRAKE BRAKE BRAKE' warning on screen; Vehicle jerks abruptly during activation
Codes mentioned: Forward Collision Warning System malfunction, Automatic Emergency Braking malfunction
Repairs/costs cited: Dealers unable to duplicate failure; testing showed system working as designed per manufacturer. No successful repairs documented.
Recalls/TSBs owners mention: Jeep/FCA states system is working as designed. No recalls or TSBs mentioned for this issue.
Brake System Failure - Loss of Braking Response
Owners report complete or near-complete loss of braking function. Applying brake pedal produces little to no reduction in forward motion. One owner experienced this after releasing the brake pedal while following traffic; another experienced this on subsequent brake applications in light rain conditions. These were collision-resulting events.
When: At least two documented incidents; one at low mileage early in vehicle ownership; one after several days of ownership.
Symptoms owners cite: No substantial decrease in forward motion when brakes applied; Brake pedal pressed with no engagement of braking system; Failure occurred in wet/light rain conditions; Failure occurred after brief brake application followed by release
Codes mentioned: ABS (Antilock Brake System) Warning Light illuminated, Brake system failure
Repairs/costs cited: No repairs documented in narratives. One owner received ABS warning notification email after accident occurred.
Recalls/TSBs owners mention: Vehicle Health Alert notification sent regarding ABS malfunction, recommending immediate dealer service. No recall or TSB mentioned.
Brake Caliper Defect - Recall Parts Availability
Left front brake caliper recall issued (NHTSA 16V168000), but dealerships have severe delays obtaining replacement parts. One dealer reported parts on back order, could only order one per week, provided conflicting information over three months, and could not provide delivery timeline. Another owner waited over one month with no resolution and dealer would not confirm vehicle safety or provide loaner.
When: Recalls issued; service requests from June 2016 onward; parts still unavailable after 3+ months for one customer.
Symptoms owners cite: Recall notification issued for left front brake caliper
Codes mentioned: NHTSA Campaign 16V168000
Repairs/costs cited: Left front brake caliper replacement required per recall. Parts unavailable; one dealership quoted extended backorder with inconsistent information. No successful repairs documented.
Recalls/TSBs owners mention: NHTSA Campaign 16V168000 (Service Brakes, Hydraulic) and Campaign 16V240000 (Power Train) issued, but manufacturer parts distribution insufficient to support recall repairs.
Brake Booster and Associated Component Failure
At 18,000 miles, brake pedal made abnormal grinding noise and stuck without warning. Fluid puddle observed under vehicle. Dealer diagnosed brake booster failure along with casket cover gasket, chain case issues, and sealant degradation requiring replacement.
When: 18,000 miles
Symptoms owners cite: Abnormal grinding noise from brake pedal; Brake pedal stuck without warning; Fluid leak underneath vehicle
Codes mentioned: Brake booster failure
Repairs/costs cited: Brake booster, casket cover gasket, chain case, and sealant replaced by East Chester Chrysler Jeep Dodge Ram.
Recalls/TSBs owners mention: Manufacturer notified and opened case number 33407052. Contact referred to NHTSA.
Unintended Acceleration While Applying Brakes
Engine revs and vehicle accelerates despite brake pedal being fully pressed. Owner had to shift to neutral and shut down engine to stop vehicle. Occurred at traffic light with no warning lights. No check engine lights present before or after incident. Owner reports seeing similar complaints in forums.
When: Within 2 days of purchase; another owner reports multiple incidents over time
Symptoms owners cite: Motor revs and tries to accelerate while brake pedal is fully pressed; Engine continues accelerating despite full brake pedal pressure; No warning lights present before or after event; Event occurs at low speed (30 mph, at traffic light)
Repairs/costs cited: Owner called dealer but received no information. No repair documented.
Recalls/TSBs owners mention: None documented; dealer had no information.
Park Position Brake Failure - Vehicle Rolls Downhill
Vehicle parked in driveway with slight incline slipped out of park and rolled down driveway into street multiple times despite being placed in park. Occurred 6-7 times in succession, each time after vehicle was put in park.
When: Recent occurrence; no mileage specified
Symptoms owners cite: Vehicle rolls from park position down driveway into street; Wheels roll despite shift lever in park; Occurred repeatedly, 6-7 times in succession
Repairs/costs cited: No repair information provided in narrative.
Recalls/TSBs owners mention: None documented.
Left Front Brake Caliper Catching/Grabbing - Vibration
Left front brake appears to catch and grab during braking, causing shaking and vibration in the vehicle.
When: Not specified
Symptoms owners cite: Left front brake catches and grabs; Shaking and vibration during braking
Repairs/costs cited: None documented.
Synthesized from 20 NHTSA owner complaints — unverified consumer
allegations, summarized for patterns. The verbatim filings appear below.