Body, generic

B0052 Passenger Seat Belt Sensor

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

B0052 concerns the front passenger's buckle sensor, reporting to the airbag module whether the tongue is latched. That signal feeds the passenger belt reminder that FMVSS 208 requires at the front outboard seats and helps the module decide how the passenger airbag and pretensioner fire. Mitsubishi uses the code in exactly this sense: its SRS manual stores B0052 with byte 11, 12, 13, 29 or 2B for a grounded line, short to supply, open circuit, invalid signal or short to another line, each after 2 seconds with the ignition on. FCA parts guidance for its restraint controller in the Dart, Cherokee and Chrysler 200 calls B0052-13 an open passenger belt sensor. GM, by contrast, logs a deployment under B0052 in its 2011 Global A modules. Airbag lamp on.

Likely causes

Loose or corroded buckle connector under the passenger seat
Faulty Hall sensor inside the passenger buckle
Buckle lead pinched or torn by the seat rails or a mat fixing
Input fault inside the airbag control module

Symptoms

  • Airbag warning lamp on
  • Passenger belt reminder warns although the belt is fastened, or stays silent
  • Passenger airbag and pretensioner strategy may assume an unbelted occupant
  • Safety note: the buckle plug sits under the seat next to airbag and pretensioner plugs; only unplug it with the battery disconnected and the wait time observed

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€60–450
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

seat belt buckle switchsrs seat wiringsrs control module

Related codes

B0050B0051B0053B0072

References: mitsubishitechinfo.com, mitsubishitechinfo.com, mitsubishitechinfo.com, static.nhtsa.gov.