B0004 LINCOLN Possible Causes
- Faulty driver knee airbag
- Driver knee airbag harness is open or shorted
- Poor electrical connection in driver knee airbag circuit
How to Fix B0004 LINCOLN Code?
Start by checking the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
When is the Code Detected?
If the Restraints Control Module (RCM) detects a short circuit between the driver knee airbag circuits and another SRS component’s circuits, it sets this Diagnostic Trouble Code (DTC) and the corresponding SRS component DTC.
Possible Symptoms
Airbag warning light illuminated
B0004 LINCOLN Meaning
The Restraints 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 one device’s circuits and another device’s circuits, it will store a DTC for each of the signal cross-coupling faults in memory. The RCM sends a message to the instrument panel cluster (IPC) to illuminate the airbag warning light. When a normal loop fault is present (a loop is either shorted to battery/ground, open circuit, or low resistance), then the signal cross-coupling diagnostic will not be active. Once the normal loop fault is repaired, the signal cross-coupling diagnostic resumes.