2020 Acura MDX Reliability Report

After Auto Idle Stop engages, the transmission slips into Neutral and won't go back into Drive or Park until the engine is restarted, sometimes several times. This happens at lights and in stop-and-go highway traffic, and drivers describe near rear-end collisions. One report adds a seized steering wheel. Others describe hesitation on acceleration that starts around 20,000 miles and gets worse, along with low-speed surging without pressing the gas. Dealers usually can't replicate these faults. One owner reports a bearing failure just outside the powertrain warranty, with a 10K estimate for a short block.

The multipurpose windshield camera fails without warning and takes Collision Mitigation Braking, Lane Keeping Assist, Road Departure Mitigation, Adaptive Cruise Control, and Auto High Beam offline at once. Dealers confirm an internal camera failure and quote roughly $1,800 to $2,300 to replace it, usually paid out of pocket on cars under 50k miles. Some warnings start out intermittent and become persistent. A smaller group describes false braking with no car ahead. One such event caused 2 injuries. Radar sensor warnings in snow also come up.

Most of these filings are about a recall repair, not a failure. Owners received a notice for the engine and engine cooling recall, often alongside a fuel system recall, but dealers had no parts, and the wait stretched well past what owners consider reasonable. Several owners on that waitlist also report stalling at various speeds or at idle with no warning light, hard starts, and repeated restart attempts. One report describes a flashing check engine light followed by a stall and total loss of electrical power, and the car had to be towed.

With adaptive cruise on at highway speed, the car brakes hard for vehicles in neighboring lanes. One new owner reports this happening more than eight times on a single commute. Other reports describe unintended acceleration: surging while coasting into a roundabout, jerky "hiccup" acceleration, or a sudden lunge when shifting into Drive. Some describe loss of power and hesitation while turning, a shift into Neutral at a stop sign, or a camera failure that disables cruise and lane keeping. Dealers can't duplicate the intermittent faults, and one reports long parts delays.

Several reports describe the Auto Idle Stop failure again. The engine won't restart when the brake is released, the brake pedal feels very hard, or the car sits in Neutral. Restarting can take several minutes or a jump start, and one owner says a software update didn't fix it. Other complaints include the electric parking brake refusing to release after Emissions System and parking brake warnings, and phantom automatic emergency braking while accelerating onto a freeway. One owner reports warped rotors with good pads.

Water gets into the rear tail light assemblies, leaving moisture and droplets inside and eventually dead LED sections. The LEDs have no replaceable bulbs, so the whole assembly has to be replaced. Owners note that the 2014–2019 models were recalled for this problem and the 2020 was not, even though the part is shared. One owner was denied warranty coverage at just over 51,000 miles. A separate report covers a lighting recall that the dealer could not complete because parts were unavailable.

A second-row belt locks, keeps tightening, and won't release. In one report it tightened around a child's chest until the parent had to cut it. Replacement belts are on back order. A crash-related report says a seat belt stopped working after an accident, which left the repaired car undrivable while the owner waited months for a replacement belt with no delivery date. Both complaints show parts availability as a recurring problem.