B1787 Rear Occupant Classification Sensor Left Collision Detection

OBD2 Code: B1787

Description: Rear occupant classification sensor left collision detection.

Definition: This code indicates a fault in the rear occupant classification system, specifically related to the left-side sensor detecting a collision or impact. The system is responsible for classifying the presence and weight of occupants in the rear seats to control airbag deployment and other safety features. A B1787 code suggests that there may be an issue with the sensor itself, its wiring, or a related component that needs inspection or repair.

B1787 – Rear Occupant Classification Sensor Left Collision Detection
Typical Severity: Moderate

Common Causes

B1787 – Rear Occupant Classification Sensor Left Collision Detection

Common causes:

• Faulty rear occupant classification sensor left
• Wiring issues in the rear occupant classification system
• Impact or collision that damaged the sensor or wiring

Common Misdiagnosis

OBD2 Code: B1787

Description: Rear Occupant Classification Sensor Left Collision Detection

Common Misdiagnosis: Faulty sensor or wiring issues are often misdiagnosed as a problem with the airbag system itself.

Common Diagnostic Steps

OBD2 Code: B1787
Description: Rear Occupant Classification Sensor Left Collision Detection

• Check for Technical Service Bulletins (TSBs): Look for any TSBs related to the rear occupant classification system that may provide guidance or updates from the manufacturer.
• Visual Inspection: Inspect the wiring and connectors associated with the rear occupant classification sensor for signs of damage, corrosion, or disconnection.
• Sensor Calibration: Verify if the rear occupant classification sensor requires recalibration after a collision. Follow manufacturer procedures for calibration.
• Diagnostic Scan Tool: Use an OBD2 scanner to check for additional codes that might indicate related issues in the airbag or seatbelt systems.
• Sensors and Modules Testing: Test the functionality of the rear occupant classification sensor using specialized tools as per manufacturer guidelines.
• Circuit Testing: Perform continuity tests on circuits connected to the sensor to ensure proper electrical flow. Check voltage levels where applicable.
• SRS System Reset: If repairs are made, reset the Supplemental Restraint System (SRS) light using a scan tool capable of SRS diagnostics.

Please note that these steps are general guidelines. Always refer to specific vehicle service manuals for detailed diagnostic and repair instructions relevant to your vehicle model and year.