B0021 LINCOLN Possible Causes
- Faulty driver side air curtain
- Driver side air curtain harness is open or shorted
- Poor electrical connection in driver side air curtain circuit
How to Fix B0021 LINCOLN Code?
Start by checking the “possible causes” listed above. Visually inspect the corresponding cable harness and connectors. Look for damaged components and check for broken, bent, pushed, or corroded connector pins.
When is the Code Detected?
If the Restraint Control Module (RCM) detects a short circuit between the driver side air curtain circuits and the circuits of another SRS component, it sets this Diagnostic Trouble Code (DTC) and the corresponding SRS component DTC.
Possible Symptoms
- Airbag warning light illuminated
B0021 LINCOLN Meaning
The Restraint Control Module (RCM) monitors all deployable device and sensor circuits for a coupled signal (short) between circuits. If the RCM detects a short circuit between the circuits of one device and another device, it will store a DTC for each of the signal cross-coupling faults in memory. The RCM sends a message to the instrument panel (IPC) to illuminate the airbag warning light. When a normal loop fault is present (a loop is either shorted to battery/ground, or open circuit or low resistance), then the signal cross-coupling diagnostics will not be active. Once the normal loop fault is repaired, the signal cross-coupling diagnostic resumes.