Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / B1B55 — PS.seatbelt sensor circuit high

B1B55 — PS.seatbelt sensor circuit high

Detailed page for trouble code B1B55.

34,405codes
59brands
11,914generic
22,491specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

B1B55

MITSUBISHI B — Body

PS.seatbelt sensor circuit high

Brand: MITSUBISHI
Type: B — Body
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or damaged wiring in the passenger seatbelt buckle/sensor circuit
  • Short to battery/ignition voltage on the sensor signal wire
  • Corroded, loose or pushed-out connector at the buckle or ECU/module
  • Failed seatbelt buckle switch or sensor assembly
  • Poor or missing ground in related harness or ECU ground
  • Faulty restraint/seatbelt control module or instrument cluster input (less common)

Symptoms

  • Seatbelt warning light illuminated or flashing
  • Seatbelt reminder chime may stay on or behave incorrectly
  • Occupant classification or airbag/pretensioner warning may appear depending on system integration
  • Possible stored fault(s) in restraint control module

What to check

  • Read and record freeze-frame and live data with a diagnostic scanner (buckle status, system status). Clear code and attempt to reproduce.
  • Visual inspection of passenger seat area: connectors, wiring harness routing, and buckle assembly for damage, corrosion or looseness.
  • Backprobe the seatbelt sensor connector with ignition ON to measure signal voltage vs. reference and ground.
  • Check continuity between buckle sensor signal pin and the control module pin; check for short to battery (12V) and short to ground.
  • Inspect and wiggle wiring while monitoring live data/voltage to see intermittent changes.
  • Check ground points and related fuses for continuity.

Signal parameters

  • Typical expected behavior: signal should be within the module’s reference range (often 0–5 V logic); “low” when circuit is pulled to ground (buckled) and near reference when open/unbuckled. Exact values are vehicle-specific — consult the Mitsubishi service manual.
  • ‘Circuit high’ means the measured signal voltage is higher than the expected maximum (often near battery voltage or above the sensor/reference threshold, e.g., >4.5 V)
  • When key ON and sensor unbuckled, signal may show near reference voltage; when buckled signal typically drops toward 0–1 V. Confirm OEM spec values before replacing parts.

Diagnostic algorithm

  1. Connect a diagnostic scanner and record the code, freeze frame and live data for the passenger buckle/sensor channel. Note state of ignition (ON) and occupant conditions.
  2. Clear the code and try to reproduce. If code returns, proceed with physical inspection.
  3. Visually inspect the passenger seatbelt buckle, cable routing, and connectors for damage, corrosion or disconnected pins. Repair or reconnect as needed.
  4. With ignition ON (engine off), backprobe the sensor connector and measure signal voltage relative to chassis ground. Compare to expected reference from service info.
  5. Check for continuity of the signal wire between the buckle connector and the restraint module connector. Also check for shorts to 12V and to ground.
  6. Wiggle the harness and connectors while monitoring live data or voltage to detect intermittent faults.
  7. If the circuit shows a short to battery or open, repair wiring (replace harness section, repair pin/terminal, clean/replace connector).
  8. If wiring and connectors test OK but sensor signal is out of spec, replace the passenger buckle/sensor assembly. Follow OEM procedures when removing/installing restraint components.
  9. After repair or replacement, clear codes and verify normalization of live data and that the code does not return.
  10. If problem remains after replacing sensor and repairing wiring, consider module input fault — refer to dealer-level diagnostics or module bench testing.
  11. Safety note: follow Mitsubishi service procedures for handling SRS and restraint components (disconnect battery and observe required wait times where specified).

Likely causes

  • Disconnected or damaged connector at passenger buckle
  • Frayed/pinched signal wire that contacts 12V or another live circuit
  • Moisture/corrosion in connector causing high resistance or false voltage
  • Defective buckle switch or sensor element

Fault status

⚠️ Status
B1B55 — Passenger seatbelt sensor circuit HIGH: signal voltage above expected range (possible open/short to battery, connector/wiring or sensor fault).
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1B54 B1B56 B1B5A B1A00
406

Browse 406 MITSUBISHI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

MITSUBISHI

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .