What Does B2587 Mean?
This code indicates the Body Control Module (BCM) or Airbag Control Module has detected an abnormal voltage condition in the passenger seat occupant detection system sensor circuit. Specifically, the sensor circuit is reading battery voltage when it should not be, suggesting a short circuit to power. This affects the supplemental restraint system's ability to properly detect passenger presence and weight for airbag deployment decisions.
Common Causes
45%
Damaged or chafed wiring harness under passenger seat causing short to power wire
30%
Failed passenger seat occupant sensor mat or pressure sensor with internal short
15%
Corroded or damaged connector at occupant sensor causing cross-circuit contamination
10%
Water intrusion or liquid damage to seat-mounted control module causing internal short
Diagnostic Steps
1
Step 1: Perform visual inspection of passenger seat area. Remove seat or access bottom of seat to inspect occupant sensor wiring harness for obvious damage, chafing against seat frame, or pinched wires. Check for any liquid contamination or wet carpeting.
2
Step 2: Disconnect occupant sensor connector(s) under passenger seat. Using a digital multimeter, measure voltage at the vehicle harness side connector. Should read 0V on signal circuits with ignition on; if battery voltage is present, wiring harness has short to power between connector and module.
3
Step 3: If no voltage found at disconnected harness, measure resistance of occupant sensor mat/module terminals per manufacturer specifications (typically 200-2000 ohms depending on system). Infinite resistance or very low resistance (under 10 ohms) indicates failed sensor.
4
Step 4: Inspect all connectors for corrosion, bent pins, or moisture. Clean with electrical contact cleaner if contaminated. Check wiring routing and secure any loose wires away from seat mechanisms and metal edges.
5
Step 5: If wiring harness shows external damage, repair or replace affected section ensuring proper insulation and routing. If sensor is faulty, replace occupant detection mat/sensor assembly and ensure proper calibration if required by system.
6
Step 6: Clear codes, perform occupant sensor system test/calibration if available through scan tool functions, and verify proper operation by cycling seat occupant detection with known weights and confirming airbag status indicator operates correctly.
Estimated Repair Cost
$150 - $800
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) or Airbag Control Module has detected an abnormal voltage condition in the passenger seat occupant detection system sensor circuit. Specifically, the sensor circuit is reading battery voltage when it should not be, suggesting a short circuit to power...
The most common cause of B2587 (Passenger Seat Occupant Detection Circuit Short To Battery) is: Damaged or chafed wiring harness under passenger seat causing short to power wire
Typical repair costs for B2587 range from $150 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is drivable but passenger airbag system may not function correctly, potentially deploying when it shouldn't or failing to deploy when needed. The passenger airbag may be disabled or operate improperly regardless of seat occupancy, creating a safety risk for passengers. Repair should be completed promptly.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B2587 to identify the root cause.
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Quick Info
Category
Body
System
Supplemental Restraint System (SRS/Airbag)
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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