B1793 – Autolamp Sensor Input Circuit Short To Ground

The ODBII code B1793 indicates a malfunction in the autolamp sensor input circuit, specifically that there is a short to ground in the circuit, which may prevent the autolamp system from functioning properly.

The severity of ODBII code B1793 is moderate.

Common Causes For: B1792 Autolamp Sensor Input Circuit Short To Battery

• Damaged wiring or connectors
• Short circuit in the autolamp sensor circuit
• Faulty autolamp sensor
• Corroded or loose connections
• Malfunctioning body control module (BCM)

Common misdiagnosis for B1793 Autolamp Sensor Input Circuit Short To Ground

• Faulty autolamp sensor
• Wiring issues or shorts in the harness
• Malfunctioning body control module (BCM)
• Incorrectly installed or damaged headlight switch
• Issues with the vehicle’s lighting system
• Faulty ground connections
• Problems with the fuse or relay associated with the autolamp system

Common Troubleshooting Steps

The OBD-II code B1793 indicates a problem with the autolamp sensor input circuit, specifically a short to ground. This code is often related to the vehicle’s automatic headlight system. 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 about the autolamp sensor circuit, including wiring diagrams and component locations.
• Visual Inspection: Inspect the wiring and connectors associated with the autolamp sensor. Look for signs of damage, corrosion, or loose connections.
• Check for any frayed wires or exposed conductors that could be causing a short to ground.
• Test the Autolamp Sensor: If accessible, test the autolamp sensor itself for proper operation. Use a multimeter to check the resistance and ensure it is within the manufacturer’s specifications.
• If the sensor is faulty, replace it.
• Check for Shorts to Ground: Use a multimeter to check for continuity between the sensor circuit and ground. If there is continuity, there is likely a short somewhere in the wiring.
• Trace the wiring back to the source to locate the short. Look for areas where the wiring may be pinched or damaged.
• Inspect Related Components: Check related components such as the Body Control Module (BCM) or any relays associated with the autolamp system. Ensure they are functioning correctly.
• If the BCM is suspected, it may require testing or replacement.
• 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.
• Monitor the autolamp system to ensure it operates correctly.
• Consult a Professional: If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with automotive electrical systems.
• Use a Scan Tool: If available, use a more advanced scan tool to check for any additional codes or data that may provide further insight into the problem. By following these steps, you should be able to identify and resolve the issue related to the B1793 code. Always ensure safety precautions are taken when working with electrical systems in vehicles.