B1559 – Door Lock Cylinder Circuit Failure

The ODBII code B1559 indicates a malfunction in the door lock cylinder circuit, which may involve issues with the wiring, connectors, or the lock cylinder itself, preventing it from functioning properly.

The severity of ODBII code B1559 is generally considered moderate.

Common Causes For: B1558 Ignition Run/Start Circuit Short To Ground

• Faulty door lock cylinder
• Damaged wiring or connectors
• Corroded terminals
• Malfunctioning door lock actuator
• Failed body control module (BCM)
• Poor ground connection
• Short circuit in the wiring harness
• Water intrusion or moisture damage

Common misdiagnosis for B1559 Door Lock Cylinder Circuit Failure

• Faulty door lock actuator
• Wiring issues or shorts in the door lock circuit
• Malfunctioning body control module (BCM)
• Key fob or remote entry system problems
• Ignition switch issues
• Faulty door latch assembly
• Battery or power supply problems

Common Troubleshooting Steps

The OBD-II code B1559 indicates a “Door Lock Cylinder Circuit Failure.” This code typically relates to issues with the door lock cylinder or its associated wiring and components. Here are some common troubleshooting steps to diagnose and resolve this issue:

• Check the Vehicle’s Manual: Refer to the vehicle’s service manual for specific information related to the B1559 code, including wiring diagrams and component locations.
• Visual Inspection:
• Inspect the door lock cylinder for any visible damage or wear.
• Check the wiring harness and connectors leading to the door lock cylinder for signs of fraying, corrosion, or disconnection.
• Ensure that the door lock actuator is properly connected and functioning.
• Test the Door Lock Cylinder:
• Use a multimeter to check the resistance and continuity of the door lock cylinder circuit. Compare the readings to the specifications in the service manual.
• If the readings are outside the specified range, the door lock cylinder may need to be replaced.
• Check the Door Lock Actuator:
• Test the door lock actuator to ensure it is functioning correctly. You can do this by applying direct power to the actuator to see if it operates.
• If the actuator does not work when powered directly, it may need to be replaced.
• Inspect the Body Control Module (BCM):
• The BCM controls the door lock functions. Check for any fault codes in the BCM using a scan tool.
• If the BCM is malfunctioning, it may need to be reprogrammed or replaced.
• Check for Short Circuits or Open Circuits:
• Use a multimeter to check for shorts or open circuits in the wiring between the door lock cylinder and the BCM.
• Repair any damaged wiring or connections as necessary.
• Clear the Code and Test Drive:
• After performing repairs, clear the B1559 code using an OBD-II scanner.
• Take the vehicle for a test drive to see if the code reappears.
• Seek Professional Help:
• If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with your specific vehicle make and model. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1559 code.