CarComplaints.com Notes: The only area of real concern for 2011 Mazda CX-9 owners is the brake booster.
In 2014, Mazda extended the warranty on the 2007-2013 CX-9 brake booster to 7 years / 90,000 miles. However this extended warranty has expired, so buyer beware.
This Mazda CX-9 brake booster failure isn't terrible in terms of repair cost — it "only" costs $550 average to fix. However it is a safety issue when the brake booster fails as it increases stopping distance. Owners have reported having to stomp on the brake pedal, & crashes/injuries have been reported due to this CX-9 brake booster defect.
At 35,000 miles, the check engine light came on. Testing it, found that it was reporting fuel gauge reporting failure. Fuel gauge only registers half full when tank is full. As I use fuel, gauge goes down. When it gauge registers empty (tank half full), check engine light goes on. Refill and check engine light goes off, but gauge returns to half full.
A D V E R T I S E M E N T S
At 35,000 miles, the check engine light came on. Testing it, found that it was reporting fuel gauge reporting failure. Fuel gauge only registers half full when tank is full. As I use fuel, gauge goes down. When it gauge registers empty (tank half full), check engine light goes on. Refill and check engine light goes off, but gauge returns to half full.
- Gary W., Bountiful, UT, US