Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / B1A54 — Occupant Detection System - Sensor Circuit Fault

B1A54 — Occupant Detection System - Sensor Circuit Fault

Detailed page for trouble code B1A54.

34,378codes
59brands
11,887generic
22,491specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

B1A54

LAND ROVER B — Body

Occupant Detection System - Sensor Circuit Fault

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

Causes

  • Open or short in occupant detection sensor (seat mat) wiring or connector
  • Loose, corroded, or damaged connector at occupant detection sensor or restraint control module
  • Faulty occupant detection sensor (pressure/capacitive mat) or sensor element
  • Poor module ground or loss of reference/ supply voltage to sensor circuit
  • Water intrusion, contamination, or physical damage to seat cushion/mat
  • Faulty restraint/airbag control module or internal circuit fault

Symptoms

  • Occupant Detection System warning or SRS/Airbag warning illuminated on dash
  • Passenger airbag disabled/unavailable message or incorrect passenger status (occupied/unoccupied)
  • Stored DTC B1A54 (may be accompanied by related occupant detection or SRS codes)
  • Intermittent or inconsistent passenger classification on scan tool live data
  • Seat removal or movement related change in warning illumination

What to check

  • Read all stored and pending codes and freeze-frame data with a capable diagnostic tool; record live data for occupant classification values
  • Inspect seat cushion and underside for signs of moisture, damage, or foreign objects
  • Visually inspect connectors, terminals and harness routing through the seat rails and into the body for chafing, pinching or corrosion
  • Check for Technical Service Bulletins (TSBs) or software updates for occupant detection or SRS modules before replacing parts
  • Verify module power and ground circuits for proper voltage and continuity
  • Perform a wiggle test on the seat harness while watching live data to reproduce the fault

Signal parameters

  • Sensor power/reference: typically a regulated reference (commonly ~5 V) — verify exact value in service data
  • Signal output: variable analog or digital value proportional to seat load — should change noticeably when weight is applied/removed
  • Return/ground: low resistance to chassis ground (< a few ohms) for module ground points
  • Resistance/impedance of sensor mat: changes with load; specific ohm values are model-dependent — consult service manual for exact values
  • CAN/BUS messages: occupant classification/status messages present on vehicle network when system powered (use scan tool to view)

Diagnostic algorithm

  1. Connect a diagnostic scan tool capable of reading SRS/occupant detection live data; record DTCs and freeze-frame information
  2. Inspect seat and harness: remove lower trim to access sensor connectors; look for corrosion, water, damaged wires, pinched sections, or loose terminals
  3. Check for TSBs or software updates for the vehicle and install if indicated
  4. With battery charged, verify sensor supply/reference voltage at the sensor connector with harness connected; compare to service data
  5. Backprobe the sensor signal wire and observe live signal while applying/removing weight to the seat — look for expected change and for intermittent behavior
  6. Perform continuity and resistance checks on harness between sensor connector and module; wiggle harness to detect intermittent opens/shorts (do not move connectors while vehicle is energized without proper precautions)
  7. If harness and supply/ground are good, disconnect sensor and measure its resistance/impedance per service manual; if out-of-spec, replace the sensor/mat
  8. If sensor and wiring check good, inspect module connector and module grounds; verify module power supply and clean/repair corrosion
  9. After replacing any component or repairing wiring, clear codes, perform any required occupant detection module calibration or SRS system setup per manufacturer procedure, then verify no DTCs return and observe correct live data/occupant status
  10. If fault persists and wiring/sensor verified, consider module fault and follow manufacturer procedure for module testing/replacement (observe prescribed handling and safety for SRS components)

Likely causes

  • Broken or chafed wires in the seat harness (common at seat rail/hinge)
  • Connector pins pushed out, bent, or corroded at the sensor or module
  • Seat cushion/pressure mat degraded or torn allowing intermittent contact or shorting
  • Failed sensor element due to moisture ingress or impact damage
  • Poor ground at seat frame or vehicle chassis
  • Module reporting internal fault due to prior short or voltage spike

Fault status

⚠️ Status
Occupant Detection Sensor Circuit Fault — open/short/intermittent signal or out-of-range value detected. Passenger classification may be incorrect or disabled.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0 - 3.0 hours

Similar codes

B1A50 B1A51 B1A53 B1A55 B1A5B B1A5C
320

Browse 320 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

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 .