Body Diagnostic Trouble Code B0058 indicates a fault reported in a vehicle’s occupant detection or restraint-related circuit. Under SAE J2012 conventions B-codes identify body system diagnostic conditions; B0058 names a signal or circuit issue within the occupant detection/restraints domain rather than a guaranteed failed part. Exact component mapping and definitions vary by make, model, and year, so you must confirm with basic electrical and network testing — power, ground, reference, and signal integrity checks plus electronic control unit (ECU) message presence — before replacing components.
What Does B0058 Mean?
This article follows SAE J2012 formatting: SAE J2012 defines DTC structure and some standardized descriptions, and the SAE J2012-DA digital annex publishes the standardized DTC wording. B0058 is a Body (B) class Diagnostic Trouble Code reporting a restraint/occupant-detection circuit condition recorded by a control module that monitors those circuits.
The code shown here does not include a hyphen suffix; it is presented without a Failure Type Byte (FTB). An FTB, if present (for example “-1A”), identifies a subtype or failure-mode detail such as source or occurrence pattern. Interpretation of B0058 varies by vehicle: some manufacturers map it to an occupant sensor mat circuit, others to seat-belt buckle sensors or harness integrity. The code is distinct as a circuit/signal plausibility or performance fault rather than a generic network communication or powertrain fault.
Quick Reference
- System: Body — occupant detection / restraint circuit
- Commonly associated with: occupant sensing mat, seat buckle sensor, or restraints control module (one possible cause)
- Typical symptom: airbag or restraints warning lamp illuminated
- Initial checks: scan for live data, verify ECU power/ground, confirm message presence on network
- Testing emphasis: measure voltage, resistance, signal waveform, and connector continuity before replacing parts
- Interpretation note: meaning can vary by make/model; consult OEM service data after basic tests
Real-World Example / Field Notes
Shop experience often shows B0058 appears as an illuminated restraints warning lamp with a recorded fault in the occupant-detection domain. One common field pattern is an intermittent lamp that clears after a key cycle but returns when the passenger seat is occupied or when the seat is adjusted; this behavior suggests an intermittent signal or poor connector contact rather than immediate module failure. Another frequent observation is water ingress or corrosion at seat connectors causing resistance changes in the occupant-sensing mat circuit — a wet connector can produce plausible but incorrect resistance readings that trigger a fault.
When a diagnostic scan tool shows the occupied/unoccupied state toggling unexpectedly in live data, that points to a sensor or harness problem commonly associated with the seat mat or buckle circuit. If live data for occupant presence is absent while other module messages remain on the Controller Area Network (CAN), check local power and ground to the restraints or occupant sensing module. If CAN messages for the restraints module are missing system-wide, broaden the scope to network/bus integrity — but do this only after confirming wiring and local supplies.
Field notes: technicians should always back up symptoms with measurements — static resistance checks on passive mats, voltage at the sensor connector with key on, and wiggle tests while watching live data. Log intermittent events with the scan tool if possible. Replace or repair connectors only after continuity, resistance, and supply tests indicate a fault; if wiring and connectors test good, then proceed to controlled bench or module-level testing per OEM guidance.
Follow a test-driven process when diagnosing B0058. Confirm power, ground, reference voltages, and Controller Area Network (CAN) message integrity with measured values and logical plausibility before concluding a module-level issue. Interpretation of B0058 often varies by make/model/year, so use basic electrical and network tests to confirm the fault path on the specific vehicle you are working on.
Symptoms of B0058
- Warning Lamp Airbag or restraint-related dash lamp illuminated or flashing intermittently.
- Communication Loss Module(s) intermittently not present or responding on the scan tool network tree.
- Diagnostic Errors Multiple stored faults or repeated occurrence after clearing codes.
- Intermittent Behavior Fault appears with vibration, door operation, or wiring movement.
- Noisy Bus Unstable live-data values or frequent network timeouts on live data display.
- Inhibited Function Some restraint features disabled or in a fallback mode (vehicle-specific).
Common Causes of B0058
Most Common Causes
Faulty or intermittent wiring/connectors between the restraint module and the vehicle network or power/ground. Corroded connector terminals, pin push-out, or poor mating can cause message loss and trigger B0058. Loss of a stable reference or low battery voltage under load is commonly associated. Software interpretation varies by manufacturer, so the same symptom set can point to different physical nodes on different vehicles.
Less Common Causes
Internal module input-stage faults after external wiring tests pass, CAN bus termination or wiring short to chassis, or a secondary module intermittently injecting invalid messages. Rarely, a manufacturing defect or water intrusion in a harness splice may produce the same code. Always confirm with targeted measurements before concluding an internal module failure.
Diagnosis: Step-by-Step Guide
Tools: OBD-II scan tool with module tree and live-data logging, digital multimeter, oscilloscope (or CAN bus analyzer), backprobe pins or harness clips, wiring diagrams/service manual, jumper/ground leads, insulated test probes, and a flashlight or mirror for connector inspection.
- Connect the scan tool and read stored codes and freeze-frame data. Note occurrence count, FTB presence, and any accompanying network faults.
- Observe live data and module list. Confirm which restraint and network nodes appear or are missing; log timestamps while you manipulate vehicle conditions.
- Check battery voltage at rest and during key-on/engine-start; confirm stable supply to restraint and associated Body Control Module (BCM) circuits.
- Inspect connectors for the restraint harness and nearby junctions for corrosion, bent pins, or moisture. Wiggle connectors while watching live data for intermittent changes.
- Measure power and ground pins at the module connector with a DMM; verify reference voltages and ground continuity to chassis. Compare to expected nominal ranges for the vehicle.
- Use an oscilloscope or CAN bus analyzer to view Controller Area Network (CAN) differential signals while the scan tool requests messages. Look for missing frames, dominant/recessive noise, or asymmetric waveform shapes indicating wiring or termination faults.
- Perform continuity checks between module connectors and the central junctions per wiring diagrams; check for shorts to chassis or low insulation resistance that may appear only when harness is stressed.
- Clear codes and re-run tests; if fault returns, note exact conditions (door open, ignition cycle, vibration). Use prolonged logging or road-test logging to reproduce intermittent faults.
- If all external wiring, power, ground, and network integrity tests pass but the fault persists, capture detailed oscilloscope logs and compare message payload plausibility. At this stage, consider that the module may have a possible internal processing or input-stage issue, but only after external inputs test good.
- Document findings and consult OEM diagnostic notes if available; provide measured values when seeking replacement module approval or warranty support.
Professional tip: Use an OEM-capable scan tool and an oscilloscope while reproducing the fault; capture On-Board Diagnostics (OBD-II) Mode 06 data, freeze-frame, and long-duration logs to correlate the event with voltage, CAN, or sensor waveform anomalies. Back-probe or use a breakout harness to measure reference, signal, power and ground simultaneously while flexing the harness. Photograph and record measured values and waveforms — replacement of a control module is justified only after power, ground, wiring continuity, and signal plausibility tests pass.
Possible Fixes & Repair Costs
Low-cost fixes usually address connector, grounding, or corrosion issues found during electrical checks. If continuity and reference voltage tests show intermittent contact or high resistance, a connector clean and secure can clear the fault. Mid-range repairs cover targeted sensor or wiring harness repairs where resistance, short-to-ground, or open circuits were confirmed with a multimeter and wiggle testing. High-cost scenarios involve replacement of an airbag inflator wiring assembly or the airbag control module after all external inputs—power, ground, reference voltage, and signal integrity—have been proven good and data logging shows internal fault signatures.
- Low: $75–$200 — justified by failed continuity, visible corrosion, or loose connector found during inspection and fixed without parts replacement.
- Typical: $250–$800 — justified by measured open/short in a harness, damaged squib resistance out of expected range, or a replaced sensor assembly after bench and in-vehicle verification.
- High: $900–$2,200+ — justified only after tests confirm wiring, power, and grounds are good and the module shows input-stage or internal processing errors requiring module replacement and safe disposal of restraint components.
Factors affecting cost: accessibility of connectors/inflators, whether airbag inflation devices require dealer parts, labor rates, and whether programming is needed after module replacement. Always base the repair on measured failures: continuity, resistance, voltage, CAN message presence, and Mode $06/UDS data where available.
Can I Still Drive With B0058?
You can often drive short distances, but you should treat the vehicle as having a reduced or disabled restraint function until the fault is resolved. Test-driven checks—confirming whether the airbag indicator lamp is illuminated and whether diagnostic data show the restraint system disabled—tell you if deployment is inhibited. If the lamp is on or the system reports disabled, avoid highway speeds and heavy traffic and drive directly to a repair facility for diagnosis.
What Happens If You Ignore B0058?
Ignoring this code can leave the occupant restraint system unready for a crash (reduced or inhibited deployment) and may prevent proper occupant protection. Continued driving risks both safety and increased repair complexity if damage or corrosion worsens over time.
Related Codes
- B0019 – Occupant Restraint Airbag Circuit Fault
- B0018 – Body Circuit Fault — Restraint Sensor Signal
- B0017 – Body Circuit Signal Integrity Fault
- B0016 – Occupant Sensing Circuit Fault (SRS)
- B0014 – Occupant Restraint Circuit Fault
- B0011 – Occupant Restraint Circuit Fault
- B0009 – Restraint System Circuit Fault
- B0008 – Supplemental Restraint System Circuit High
- B0007 – Supplemental Restraint System Circuit Fault
- B0006 – Restraint Deployment Commanded Too Long
Key Takeaways
- B0058 is a body (B-series) code indicating a restraint system circuit fault—interpretation varies by vehicle and requires electrical/network tests.
- Diagnosis must be test-driven: power, ground, reference voltage, continuity, resistance, CAN/message presence, and Mode $06 checks.
- Replace or repair only after measurements justify the action; module replacement is only considered after external inputs test good.
- Drive cautiously and seek diagnosis promptly if the restraint indicator is lit or system shows disabled status.
Vehicles Commonly Affected by B0058
B0058 is commonly seen across many passenger cars and SUVs; it is often reported on Toyota, Honda, and Ford models due to wide global volume and similar restraint system architectures. Vehicles with multiple airbag squibs, seatbelt pretensioners, and distributed sensor networks can show this code more frequently when connectors age or when CAN wiring is compromised. Interpretation and exact component mapping vary by make, model, and year—confirm with basic electrical and network tests.
FAQ
Can I clear B0058 and see if it returns?
You can clear the code with a scan tool to test whether the fault is intermittent, but clearing is only a diagnostic step—not a repair. If the code returns after clearing, record freeze-frame and live-data, then perform electrical tests (continuity, resistance, reference voltage) and network checks. Use wiggle tests and re-scan to reproduce the fault before replacing any component.
Can a bad battery or low voltage cause B0058?
Yes; supply voltage outside the expected range can cause restraint system anomalies. Measure battery resting voltage and cranking voltage, and check local module supply and ground pins for stable voltages. If low or noisy supply is found, stabilize and retest. Only after stable power and grounds are confirmed should you proceed to signal and continuity diagnostics or consider module-level issues.
Is this code always an airbag module failure?
No. B0058 indicates a circuit or signal fault in the restraint system; it does not universally mean the airbag control module is bad. Most often the cause is wiring, connector corrosion, or a sensor/squib anomaly. Module replacement is only justified after power, ground, wiring continuity, and input signals are verified good and diagnostic data point to an internal processing or input-stage issue.
How will a technician confirm the failing circuit?
A technician uses a test-driven approach: retrieve freeze-frame and live-data, verify airbag lamp status, check reference voltages, perform continuity and resistance measurements on suspect circuits, and monitor CAN or diagnostic messages. Wiggle testing and backprobing harnesses while observing changes in data help pinpoint intermittent faults. Repair actions must match measured failures, not assumptions.
Is it expensive to repair B0058?
Cost depends on the confirmed fault: connector cleaning is inexpensive, wiring harness repair is moderate, and inflator or module replacement is costly. The final price is justified by your diagnostic results—continuity faults support harness repair, abnormal squib resistance supports component replacement, and confirmed internal module errors support module replacement after all external inputs test good.