B1346 – Heated Backlite Input Circuit Short To Battery

The ODBII code B1346 indicates a short circuit in the heated backlite input circuit, which means there is an electrical fault causing the circuit to connect directly to the battery, potentially leading to overheating or malfunction of the heated backlite system.

The severity of ODBII code B1346 is moderate.

Common Causes For: B1345 Heated Backlite Input Circuit Short To Ground

• Shorted wiring or connectors
• Faulty heated backlite switch
• Malfunctioning heated backlite element
• Corroded or damaged connectors
• Ground circuit issues
• Faulty body control module (BCM)

Common misdiagnosis for B1346 Heated Backlite Input Circuit Short To Battery

• Faulty heated backlite element
• Shorted wiring harness
• Defective body control module (BCM)
• Malfunctioning switch or relay
• Incorrectly installed or damaged connectors
• Grounding issues
• Faulty temperature sensor

Common Troubleshooting Steps

The OBD-II code B1346 indicates a problem with the heated backlite input circuit, specifically a short to battery. This code is often related to the rear window defroster or heated backlight system. Here are some common troubleshooting steps to diagnose and resolve the issue:

• Visual Inspection:
• Check the wiring and connectors associated with the heated backlite system for any visible damage, fraying, or corrosion.
• Look for any signs of short circuits, such as melted insulation or exposed wires.
• Check Fuses:
• Inspect the fuses related to the heated backlite or rear defroster circuit. Replace any blown fuses and see if the code returns.
• Test the Heated Backlite Switch:
• If applicable, test the switch that controls the heated backlite. Ensure it is functioning correctly and not stuck in the “on” position.
• Measure Voltage:
• Use a multimeter to measure the voltage at the heated backlite input circuit. Ensure that the voltage is within the manufacturer’s specifications.
• Check for any voltage present when the system is off, which could indicate a short.
• Check Ground Connections:
• Ensure that all ground connections related to the heated backlite circuit are secure and free of corrosion. A poor ground can cause erratic behavior.
• Inspect the Heated Backlite Element:
• If the vehicle has a heated backlite element (like a rear window defroster), inspect it for any breaks or damage. A damaged element can cause a short 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.
• Perform a Continuity Test:
• With the vehicle off, perform a continuity test on the wiring harness associated with the heated backlite circuit to check for shorts to ground or battery.
• Check for Water Intrusion:
• Inspect the area around the rear window for any signs of water intrusion that could affect the electrical components.
• Consult Wiring Diagrams:
• Refer to the vehicle’s service manual for wiring diagrams to understand the circuit better and identify any other components that may be involved. 1
• Replace Faulty Components:
• If any faulty components are identified during testing (such as the switch, wiring, or heated backlite element), replace them as necessary. 1
• Clear Codes and Test Drive:
• After repairs, clear the trouble codes using an OBD-II scanner and take the vehicle for a test drive to see if the code returns. If the issue persists after following these steps, it may be advisable to consult a professional mechanic or technician for further diagnosis and repair.