DTC DETECTING CONDITION:
Curtain airbag sensor (LH) is faulty.
If DTC 59 is displayed, the circuit within the curtain airbag sensor (LH) is faulty.
Replace the curtain airbag sensor (LH). 
AIRBAG SYSTEM (DIAGNOSTICS) > Diagnostic Chart with Trouble Code
DTC 59 CURTAIN AIRBAG SENSOR LH FAILURE
DTC DETECTING CONDITION:
Curtain airbag sensor (LH) is faulty.
If DTC 59 is displayed, the circuit within the curtain airbag sensor (LH) is faulty.
Replace the curtain airbag sensor (LH).