B1792 – Autolamp Sensor Input Circuit Short To Battery

The ODBII code B1792 indicates that there is a short circuit in the autolamp sensor input circuit, causing it to receive a constant voltage from the battery instead of the expected variable signal.

The severity of ODBII code B1792 is moderate.

Common Causes For: B1791 Autolamp Sensor Input Circuit Open

• Shorted wiring or connectors
• Faulty autolamp sensor
• Corroded or damaged connectors
• Malfunctioning body control module (BCM)
• Incorrectly installed or damaged harness
• Grounding issues
• Water intrusion or moisture in the circuit

Common misdiagnosis for B1792 Autolamp Sensor Input Circuit Short To Battery

• Faulty autolamp sensor
• Shorted wiring harness
• Defective body control module (BCM)
• Malfunctioning headlight switch
• Incorrectly installed aftermarket lighting
• Grounding issues
• Faulty connectors or terminals

Common Troubleshooting Steps

The OBD-II code B1792 indicates a problem with the autolamp sensor input circuit, specifically a short to battery. 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 and wiring diagrams.
• Visual Inspection:
• Inspect the wiring and connectors associated with the autolamp sensor. Look for any signs of damage, fraying, or corrosion.
• Check for any loose or disconnected wires that may be causing a short circuit.
• Test the Autolamp Sensor:
• If accessible, test the autolamp sensor itself for proper operation. Use a multimeter to check the resistance and ensure it falls within the manufacturer’s specifications.
• If the sensor is faulty, replace it.
• Check for Shorts:
• Use a multimeter to check for continuity in the wiring harness. Look for any shorts to battery voltage or ground.
• Disconnect the sensor and check the wiring harness for shorts to battery voltage. If a short is found, trace the wiring to locate the source of the short.
• Inspect the Fuse:
• Check the fuse related to the autolamp system. A blown fuse may indicate an underlying issue, such as 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.
• Check Ground Connections:
• Ensure that all ground connections related to the autolamp system are clean and secure. Poor ground connections can lead to erratic behavior and false codes.
• Test the Body Control Module (BCM):
• If all other components check out, 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 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 steps, you should be able to identify and resolve the issue related to the B1792 code.