B1351 – Ignition Key-In Circuit Short To Battery

The ODBII code B1351 indicates a malfunction in the ignition key-in circuit, specifically a short to battery, which means that the circuit detecting whether the ignition key is in the ignition switch is receiving an unintended voltage from the battery.

The severity of ODBII code B1351 is moderate.

Common Causes For: B1350 Heated Backlite Relay Short To Ground

• Shorted wiring in the ignition key-in circuit
• Faulty ignition switch
• Damaged connectors or terminals
• Corroded wiring
• Malfunctioning body control module (BCM)
• Improperly installed aftermarket accessories
• Faulty key-in switch or sensor

Common misdiagnosis for B1351 Ignition Key-In Circuit Short To Battery

• Ignition switch failure
• Faulty ignition lock cylinder
• Shorted wiring harness
• Defective body control module (BCM)
• Malfunctioning keyless entry system
• Battery issues
• Faulty relays or fuses
• Problems with the anti-theft system
• Incorrectly installed aftermarket accessories
• Grounding issues

Common Troubleshooting Steps

The OBD-II code B1351 indicates a problem with the ignition key-in circuit, specifically a short to battery. This code is often related to the vehicle’s security system or ignition switch. Here are some common troubleshooting steps to diagnose and resolve the issue:

• Check the Vehicle’s Manual: Refer to the vehicle’s service manual for specific information related to the B1351 code and the ignition key-in circuit.
• Visual Inspection:
• Inspect the ignition switch and surrounding wiring for any visible damage, corrosion, or loose connections.
• Check the wiring harness for any signs of wear, fraying, or shorting against metal surfaces.
• Test the Ignition Switch:
• Use a multimeter to test the ignition switch for proper operation. Ensure that it is functioning correctly and that the contacts are not stuck or damaged.
• Check for Shorts:
• Inspect the wiring in the key-in circuit for any shorts to battery voltage. This may involve checking the continuity of the wires and ensuring they are not touching any other wires or metal surfaces.
• Inspect the Key Cylinder:
• If applicable, check the key cylinder for any issues. Sometimes, a malfunctioning key cylinder can cause problems with the key-in circuit.
• Scan for Additional Codes:
• Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues.
• Check Fuses:
• Inspect the fuses related to the ignition and security systems. A blown fuse can sometimes cause circuit issues.
• Test the Body Control Module (BCM):
• If the ignition switch and wiring are functioning correctly, the issue may lie within the BCM. Test the BCM for proper operation and check for any software updates or recalls.
• Clear the Code:
• After performing the necessary repairs, clear the trouble code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Consult a Professional:
• If the issue persists after performing these steps, it may be best 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 B1351 code.