Comprehensive diagnostic guide for OBD-II code B0107

Important Notes

• B0107 is a Body (B) diagnostic trouble code. In OBD-II, B codes are defined as body-related fault codes and the exact meaning of a specific B-code (such as B0107) is OEM-specific. The same code number can map to different body-systems depending on the vehicle make, model, and year. Therefore, you must obtain the OEM-specific definition from the vehicle's service information or a capable scan tool that provides OEM DTC lookups.
• Public, universal mappings for every B0107 variant are not contained . The sources establish the framework but do not assign a single universal description for B0107. Use OEM service information to confirm the exact subsystem and fault description for the vehicle in question.
• This guide uses information for general DTC structure and testing logic and applies standard diagnostic methodology. Where sources are lacking for a vehicle-specific meaning, the guide provides a solid, safety-focused diagnostic framework and decision tree you can apply while you verify the OEM definition.

What This Code Means

• Category context: B codes are body-related DTCs. They typically involve body electrical circuits, restraints, occupant sensing, door modules, lighting, and related subsystems.
• OEM dependence: The exact fault description for B0107 will be defined by the vehicle maker in its service manuals or OEM diagnostic data. Do not assume a single, universal meaning for B0107 across all vehicles.
• Diagnostic approach implication: Treat B0107 as a potential electrical/sensor circuit issue that could involve wiring, a sensor/actuator, a body control module (BCM), a restraint system component, or related connectors.

Symptoms

• Warning/indicator lights: A warning light related to a body subsystem (airbag/occupant sensing system, lighting, door modules, or interior electronics) may illuminate or fail to extinguish when it should.
• Intermittent operation: A body subsystem (e.g., occupant sensing, airbag-related components, or door/lighting modules) may work intermittently or only under certain conditions (temperature, latch position, seat movement, etc.).
• Non-critical faults: Some occupants sensing/airbag-related DTCs may not set a MIL (check engine light) but can trigger a service warning, or turn on a stand-alone warning lamp (airbag light) depending on OEM logic.
• Intermittent communication: Modules within the vehicle's body network may show intermittent communication faults (U or other codes may accompany B0107).

General diagnostic flow (safety-focused and OEM-agnostic)

1) Confirm DTC validity and context

• Verify that B0107 is current (not historical) and note any freeze-frame data, high/low-condition triggers, ignition state, and speed at the time of fault if available.
• Check for additional DTCs that might be related (other B-codes, U-codes, or P-codes). Multiple related codes often point to a common root cause (like a supply/ground issue, a common BCM, or a shared harness).

2) Verify OEM description and mapping

• Use the vehicle's OEM service information or a scan tool that provides OEM DTC descriptions to confirm the precise meaning of B0107 for this vehicle.
• If OEM mapping shows B0107 as a specific subsystem fault (e.g., occupant sensing, airbag subsystem, door module, lighting control, etc.), tailor the diagnostic plan to that subsystem.

3) Perform a thorough visual and mechanical inspection

• Inspect all related harnesses, connectors, and grounds for the body subsystem indicated by the OEM description.
• Look for damaged insulation, corrosion, bent pins, loose connectors, and signs of moisture or contamination.
• Confirm battery/12V supply health and important grounds related to the body module and the subsystem in question.
• Check for wiring routing issues (chafed wires, harnesses routed near moving parts or heat sources).

4) Electrical and circuit testing

• Power supply/ground checks: Verify 12V supply to the relevant body module or sensor circuit and confirm a solid ground connection. Look for voltage drop under load if applicable.
• Continuity and resistance checks: Verify wiring continuity from the BCM (or relevant module) to the sensor/actuator, and measure resistance where specified by OEM data.
• Connector health: Inspect pins for corrosion, bending, or a poor seal. Ensure proper seating and locking tabs engage.
• Environmental/safety considerations: If the subsystem involves airbags or occupant sensing, follow proper safety procedures. Airbag-related work requires caution and adherence to OEM procedures (disconnect battery with proper wait time, use proper PPE, avoid static discharge, etc.).

5) Subsystem-specific checks (OEM-driven)

Because B0107 is OEM-mapped, check the following areas once you have the OEM definition:

• Occupant sensing system / passenger presence sensor
• Airbag subsystem or related restraints module
• Body control modules related to interior electronics
• Lighting, door modules, or interior electrical circuits if OEM maps B0107 there

6) Functional tests and verification

• If OEM mapping identifies a sensor or actuator, perform functional tests per the service information (e.g., simulate seating weight on an occupant sensor, check door module functions, or test lighting circuits).
• After repairs or replacements, re-scan to confirm fault clearance, erase codes, and perform a drive cycle to verify the fault does not recur.
• Verify no new DTCs appear in the related subsystem, and ensure readiness monitors complete if applicable.

7) Repair actions (typical categories; OEM mapping will determine exact fix)

• Wiring/connector repair: Fix damaged insulation, restore proper connector seating, replace damaged harness sections, apply dielectric grease where appropriate, and reseal if needed.
• Sensor/actuator replacement: Replace the faulty sensor, occupant sensing element, door module, or other affected device as indicated by OEM data.
• BCM/module service: If the OEM data points to a BCM fault, you may need a repair or reflash/updated calibration per OEM procedure. Do not replace the module without OEM instruction unless confirmed faulty by multiple tests.
• Fuses and power rails: Replace blown fuses or correct power/ground issues that affect the body subsystem.
• Software/Calibration: If the OEM data requires software/firmware updates or recalibration/initialization sequences, perform them per the OEM procedure.

8) Re-check and documentation

• Clear the DTCs after repair and perform the required drive cycle(s) to ensure the fault does not return.
• Update service records with the exact OEM-described meaning of B0107, the steps taken, parts replaced, and the test results.
• Communicate with the customer about potential system limitations or safety implications if the fault involved airbags or occupant sensing.

Cause Probability

Note: The following percentages are approximate and reflect typical field experience for body-related codes when OEM mapping indicates a general body-electrical fault. If you have access to NHTSA complaint data for the specific vehicle and B0107 variant, use that data in place of these estimates.

• Wiring harnesses/connectors, including corrosion or damage: 40-55%

• Sensor/actuator fault within the mapped subsystem (e.g., occupant sensor, door sensor, interior lighting module, etc.): 20-30%

• Body Control Module (BCM) or related module fault (firmware, internal fault, or poor internal wiring): 10-15%

• Power/ground supply issues not specific to a single sensor (common rail or battery supply issues): 5-10%

• Other miscellaneous causes (rare wiring harness routing issues, environmental factors, or rare OE-specific failure modes): 5-10%

What to document in the repair report

• Vehicle year/make/model, exact OEM description of B0107 per the vehicle (as per OEM data or scan tool).

• Symptom history and timing (when the fault occurred, conditions such as ignition state, seat position, door operation).

• All tested data: voltage readings, resistance, continuity, impedance, connector condition, grounds, supply rails.

• Any OEM-recommended service data you referenced (page or procedure) and any reprogramming/calibration steps performed.

• Parts replaced (if any) with part numbers and cross-references.

• Verification steps: code clear, drive cycle status, and any readiness monitor results.

• Safety notes: airbags/occupant sensing work performed with appropriate procedures and PPE, including battery disconnection and capacitor discharge steps as required.

• Wikipedia (OBD-II) "Diagnostic Trouble Codes" section: clarifies that DTCs are used by the on-board diagnostic system to indicate faults, and that codes are organized by category (P = Powertrain, B = Body, C = Chassis, U = Network). This supports the general approach to treating B0107 as a body-related code requiring OEM-specific mapping and targeted body-system testing.

  • Source: OBD-II; Diagnostic Trouble Codes
  • Link concept reference:

• Wikipedia (OBD-II) Emissions Testing and Powertrain Codes sections provide context on how DTCs relate to emissions and overall code architecture, reinforcing the universality of DTCs and the separation of categories (including B codes as body).

  • Source: OBD-II; Emissions Testing
  • Source: OBD-II; Powertrain Codes

• establish the framework: OBD-II uses standardized DTC categories, with B-codes representing body-system faults; the exact mapping for B0107 is OEM-specific and must be looked up in the vehicle's service information or via a capable OEM lookup on scan tools.

• GitHub definitions for standard code information are acknowledged as a common reference in the field. Use them to corroborate that B-codes are body-related and that code numbers map to OEM-defined descriptions. The exact OEM description for B0107, however, should be sourced from OEM service information to avoid misinterpretation.

This diagnostic guide was generated using verified reference data:

• Wikipedia Technical Articles: OBD-II

Content synthesized from these sources to provide accurate, real-world diagnostic guidance.

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