What the source says
The documented condition
Mazda documented water reaching the liftgate switch connector on specified CX-30 vehicles. Moisture or corrosion can stop the liftgate-mounted lock switch from working, may store B11C4:23 and, when the connector is rusted, may also drain the battery. A weak battery, unrelated wiring fault or latch problem can produce overlapping symptoms.
Compare the pattern
Symptoms and vehicle scope
Words owners may use
- CX-30 battery dead after car wash
- liftgate lock button not working
- rear hatch switch stopped working
- tailgate button does nothing
- battery keeps going flat
- water behind Mazda rear emblem
- B11C4 code
Symptoms in the record
- The lock switch on the interior liftgate trim does not operate the door locks
- The concern may appear after a high-pressure wash or condensation
- Moisture or corrosion is found at the switch connector during professional inspection
- The 12-volt battery may discharge while the vehicle is parked
Vehicles and limits
- US-specification, Mexico-built 2020 to 2022 Mazda CX-30 vehicles
- The bulletin also lists specified Mazda3, CX-5 and MX-30 vehicles
- Switch equipment and production details should be checked by VIN
B11C4:23Manufacturer position
What the official procedure directs
Mazda directs technicians to inspect the switch connector for moisture and corrosion. The published repair waterproofs a sound connector or replaces corroded switch and harness components before sealing the connection.
Mileage context
The bulletin uses model, production and equipment criteria rather than a mileage threshold. Warranty application was limited to verified complaints on eligible vehicles.
Original evidence
Open the documents behind this record.
Manufacturer bulletin · NHTSA MC-10206952 · Jan 31, 2022
Liftgate switch water intrusion and connector corrosion
The revised Mazda bulletin lists 2020 to 2022 CX-30 vehicles, B11C4:23, possible battery drain and the connector repair steps.
Repair paths and safe checks
Match the action to the evidence.
Inspect and repair the liftgate switch connection
A Mazda technician removes the trim, checks for water and rust, replaces the affected switch or harness connector when needed, then seals the connection using the bulletin procedure.
Corroded terminals should not simply be taped over. The bulletin separates clean, wet connections from parts that require replacement.
Document moisture timing and remove parked accessories
Note whether the fault followed a wash or rain, test the liftgate switch once while parked and unplug aftermarket devices before the vehicle sits. Tell the technician if the battery has already needed a jump.
Do not remove wet trim or probe connectors with the battery connected. Avoid directing a pressure washer at the rear emblem until the fault is inspected.
Record reviewed in the source on August 2, 2026. Confirm the current document and VIN instructions before arranging work.
How we check a problem · All records for the 2020 Mazda CX-30