Code B0013 indicates a fault in the passenger knee bolster deployment control circuit. The knee bolster is a supplemental restraint device designed to protect the passenger's lower body during a collision, and this code means the airbag control module has detected an electrical issue in its deployment loop.
The most common cause is an open, short, or high resistance in the wiring harness or connectors between the SRS module and the knee bolster, often due to corrosion, pin damage, or chafing.
The deployment squib inside the knee bolster assembly may have failed internally, causing an open or short circuit that triggers the code.
Wiring insulation damage can cause the circuit to short to chassis ground or to a power source, leading to a circuit fault.
The airbag control module itself may have an internal fault, but this is rare and should only be considered after ruling out all other causes.
The definition is universal; the diagnostics are engine-specific. Open your vehicle for the codes documented for it:
The vehicle can be driven, but the passenger knee bolster may not deploy in a crash, increasing the risk of injury. The airbag warning light also indicates the entire SRS system may be disabled, so prompt diagnosis is recommended.
No, a B0013 code typically indicates a circuit fault that would prevent deployment, not cause an unwanted deployment. The SRS module is designed to disable the system when a fault is detected.
No, the SRS module is rarely the cause. The fault is almost always in the wiring, connectors, or the knee bolster squib itself. Replacing the module without proper diagnosis is a common misdiagnosis.
Clearing the code with a scan tool is possible, but if the underlying fault is not repaired, the code will return immediately. SRS codes do not self-clear even if the problem is intermittent; they must be manually erased after repair.