B1343 – Heated Backlite Input Circuit Failure
The ODBII code B1343 indicates a failure in the heated backlite input circuit, which typically refers to an issue with the rear window defroster system’s electrical circuit.
The severity of ODBII code B1343 is generally considered moderate.
Common Causes For: B1342 ECU Is Defective
- Faulty heated backlite element
- Damaged wiring or connectors
- Short circuit in the circuit
- Open circuit in the circuit
- Faulty body control module (BCM)
- Corroded terminals or connections
- Blown fuse related to the heated backlite system
Common misdiagnosis for B1343 Heated Backlite Input Circuit Failure
- Faulty rear defroster switch
- Wiring issues or shorts in the circuit
- Defective rear defroster grid
- Malfunctioning body control module (BCM)
- Incorrectly diagnosed as a battery or charging system issue
- Faulty connectors or terminals
- Issues with the vehicle’s climate control system
Common Troubleshooting Steps
The OBD-II code B1343 indicates a “Heated Backlite Input Circuit Failure.” This code is typically associated with issues in the heated rear window circuit, which may affect the operation of the rear defroster. Here are some common troubleshooting steps to diagnose and resolve this issue:
- Check the Owner’s Manual: Refer to the vehicle’s service manual for specific information related to the heated backlite system and wiring diagrams.
- Visual Inspection: Inspect the rear window for any visible damage or defects.
- Check the wiring harness and connectors leading to the heated backlite for signs of wear, corrosion, or disconnection.
- Test the Heated Backlite Element: Use a multimeter to check the resistance of the heated backlite element. If the resistance is outside the manufacturer’s specifications, the element may be faulty and need replacement.
- Check the Fuse: Locate the fuse associated with the heated backlite circuit and check if it is blown. If it is, replace it and see if the code returns.
- Inspect the Relay: If applicable, check the relay that controls the heated backlite circuit. Test the relay for proper operation and replace it if necessary.
- Check for Short Circuits: Inspect the wiring for any signs of short circuits or grounding issues. Use a multimeter to check for continuity and shorts in the circuit.
- Scan for Additional Codes: Use an OBD-II scanner to check for any other related trouble codes that may provide more context to the issue.
- Test the Switch: If the vehicle has a switch to activate the heated backlite, test the switch for proper operation. Ensure it is sending the correct signal to the control module.
- Inspect the Control Module: If all other components check out, the issue may lie within the control module that manages the heated backlite system. Check for software updates or faults in the module.
- Clear the Code and Test Drive: After performing repairs, clear the trouble code using an OBD-II scanner and take the vehicle for a test drive to see if the code returns.1
- 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 B1343 code.