Code Definition

B2118 — Passenger Sid, Side mount Airbag Low capacitance on Squib

System: Body  |  Type: Generic (OBD-II Standard)  |  Make: Ford

About B2118

B2118 is a generic (obd-ii standard) body diagnostic trouble code recorded for Ford vehicles. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B2118 is stored, the module has detected a signal or supply voltage lower than the expected operating range.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

Because B2118 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The Restraints Control Module (RCM) continuously monitors each airbag squib circuit by performing a resistance and capacitance check on the firing loop. DTC B2118 sets when the RCM measures the squib capacitance on the passenger side, side mount airbag firing circuit to be below the calibrated minimum threshold. The squib is the small electrically initiated igniter inside the airbag inflator, and the loop capacitance is measured to confirm the firing circuit is intact and ready to deliver enough energy to deploy the bag in a crash event. When this code is set, the airbag warning lamp will illu...

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