Comprehensive Diagnostic Guide for OBD-II Code B0117

Disclaimer on code meaning

• B codes are "Body" diagnostics. The OBD-II standard defines DTC categories (P = Powertrain, B = Body, C = Chassis, U = Network). The available Wikipedia content confirms this general structure and the existence of body-related codes within the OBD-II framework. Because the exact description of B0117 is not defined , the precise fault description for B0117 is vehicle/manufacturer specific. For a definitive meaning, consult OEM service information or standardized GitHub DTC definitions that map B codes to specific circuits/sensors.
• Emissions-related context: B-codes are less commonly emission-related than P-codes but can still affect vehicle function and required checks during diagnostics.

Symptom expectations (how customers commonly report B-code symptoms)
Note: Because B0117's exact circuit is not defined , symptoms are described in generic body-system terms. Use these as a starting point and correlate with the vehicle-specific wiring and BCM (Body Control Module) layout.

• MIL/Check Engine Light may be on or flashing, or the vehicle may enter a "limp" or degraded operation mode if the body circuit fault affects critical functions.
• Intermittent or persistent issues with body-related systems (doors, interior electronics, lighting, HVAC wiring, switches, or other body sensors) depending on which circuit B0117 maps to in the OEM definition.
• Doors, locks, lighting, or interior electronics behaving abnormally or not responding as expected.
• Auxiliary body functions (e.g., interior lighting, proximity sensors, switches, or non-engine-related inputs) showing unusual behavior.

Diagnostic Approach

1) Confirm scope and origin

• Verify code presence with a reliable scan tool. Note if B0117 is stored, pending, or history code.
• Retrieve freeze-frame data, recent fault history, and any related DTCs (P/C/U/C codes that accompany B0117). This can help locate the affected body subsystem (doors, lighting, comfort electronics, etc.).

2) Gather context

• Identify the exact vehicle make/model/year and know which BCM/Body subsystem controls the suspected area.
• Check for OEM service information or GitHub-defined mappings for B0117 to determine the exact circuit or sensor involved (since don't define B0117 specifically).

3) Visual and mechanical inspection

• Inspect the wiring harnesses and connectors in the suspected body area (doors, instrument panel, interior wiring paths, behind trim). Look for damaged insulation, chafed wires, pin corrosion, bent pins, moisture intrusion, and signs of previous repair.
• Inspect grounds and power feeds to the BCM and any related body modules. A poor ground or inconsistent supply can cause multiple body symptoms.
• Check fuses and relay operation for the suspected body circuits.

4) Electrical testing (assuming no OEM wiring diagram is readily at hand)

• With ignition off, inspect key connectors for corrosion, bent pins, or foreign debris. Re-seat connectors firmly.
• Verify supply voltage to the suspected BCM input(s) and ensure stable battery voltage (typical 12.6-14.8 V when running, with no significant dips).
• Perform a data-stream check (when the vehicle is in a stable state) to observe the BCM inputs/outputs associated with the suspected circuit. Look for open circuits, short to ground, or short to voltage conditions.

5) Targeted testing based on the mapped circuit (vehicle-specific)

• If the B0117 mapping points to a particular sensor or switch, test that device per OEM service data (resistance/continuity, actuator operation, switch state, etc.).
• If the fault is in a door, switch, or interior circuit, test all related switches, door ajar inputs, and interlock circuits with a multimeter and, if possible, a scan-tool diagnostic mode that can read switch states.
• If the fault involves lighting or illumination circuits, inspect the affected lamps, ballast/control modules, and associated wiring for ground issues and short circuits.

6) Reproduce and confirm

• After repairs or component testing, clear the DTCs and operate the vehicle through normal cycles to confirm the fault does not return. Recheck for any related codes or new symptoms.
• If B0117 reappears, re-check the related circuit(s) and perform a more in-depth BCM diagnosis or software/firmware check as indicated by OEM data.

7) Consider software and hardware flow

• If the vehicle uses a modular Body Control Module that can be re-flashed or updated, verify whether there are OEM service bulletins (TSBs) addressing B-series body codes or BCM communication issues.
• If a BCM fault is suspected, factory diagnostics may be required to test, reprogram, or replace the module. Ensure you follow proper anti-static precautions and battery-maintenance practices during BCM work.

Probable Causes

Note: The probabilities below are not OEM-specific for B0117, since the exact meaning of B0117 is not provided . They reflect common patterns seen with body-related codes and are presented as practice guidance.

• Wiring harnesses and connectors (loose, corroded, pin damage, water intrusion, chafed insulation): 40-60%
• Grounding and power supply issues (poor grounds, battery/alternator intermittency affecting BCM inputs): 5-15%
• Body Control Module (BCM) or related module fault (software/firmware issues, communication faults, aging BCM): 10-20%
• Sensor(s) or switch(s) related to the mapped body circuit (faulty door switches, interior sensors, lighting control inputs, etc.): 15-25%
• Ancillary or aftermarket interference (non-OEM wiring, added components, improper repairs): 5-15%

Reference context and sources

• Code structure and category overview: OBD-II system and the existence of DTC categories including P (Powertrain) and B (Body). This is described in the OBD-II overview sections of .
• Emissions testing context for OBD-II: Highlights how diagnostics relate to emission frameworks and the monitoring of various parameters.
• Standard code information framework: The general concept that OBD-II codes are standardized by category (P, B, C, U) and that specific mappings may vary by vehicle/maker; OEMs and standard definitions provide the exact meaning for a given code.
• NHTSA data note: do not include NHTSA complaint data for B0117. If NHTSA data were available, it would be used to weight cause probabilities; in its absence, field experience is used as guidance.

What you should do next (practical checklist)

• Step 1: Confirm B0117 is current and read any related codes. Note freeze-frame data and history.
• Step 2: Determine vehicle-specific meaning of B0117 via OEM service information or trusted GitHub DTC mappings. This is essential to target the correct circuit.
• Step 3: Inspect wiring and connectors in the mapped body circuit. Check grounds and power feeds to the BCM and related modules.
• Step 4: Perform circuit testing appropriate to the mapped body subsystem (doors, lighting, interior electronics, etc.), using a meter and scan tool data.
• Step 5: If no fault is found in wiring, evaluate BCM behavior (reflash/firmware update if applicable, inspect for corrosion or water intrusion, consider module replacement if data indicates).
• Step 6: Clear codes, cycle the vehicle, and verify that B0117 does not recur. If it recurs, escalate with OEM guidance and consider professional BCM diagnostics.
• Step 7: Document findings, repair steps, and test results for service records and future diagnostics.

Safety Considerations

• Disconnect power and follow proper lockout/tagout procedures when working on BCMs or any high-current body circuits to avoid short circuits or shock hazards.
• Be mindful of airbag systems and other safety-critical body systems; follow OEM guidelines before disconnecting any related components.
• Use appropriate PPE and avoid static discharge when handling control modules and sensitive electronics.

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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