Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / B1B87 — seat height speed sensor of the engine / position motor relay

B1B87 — seat height speed sensor of the engine / position motor relay

Detailed page for trouble code B1B87.

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

B1B87

LAND ROVER B — Body

seat height speed sensor of the engine / position motor relay

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

Causes

  • Faulty seat height position sensor (speed/position transducer)
  • Failed position motor relay or relay coil circuit
  • Blown fuse or poor power supply to relay/sensor
  • Open, shorted, corroded or pinched wiring / connector
  • Poor ground connection at seat or module
  • Mechanical obstruction or seizure of seat height motor/gears

Symptoms

  • Seat height will not adjust or moves intermittently
  • Seat moves more slowly than normal or stops mid-travel
  • Audible relay clicking or repeated relay operation when adjusting seat
  • DTC B1B87 (and possibly related seat position codes) stored in memory
  • Other seat adjustment functions may be affected or behave erratically
  • Possible blown fuse or tripped circuit protection

What to check

  • Read freeze-frame and full DTC list with a capable scan tool; note any related codes
  • Visually inspect seat, rails, motor, sensor and relay connectors for corrosion, damage or water
  • Check fuses and power supply circuits for the seat adjustment system
  • Wiggle test harnesses while operating seat to try to reproduce fault
  • Verify good ground at seat and module grounding points
  • Listen for relay operation when commanding seat height; observe motor activity

Signal parameters

  • Supply voltage to relay coil: ~12 V when energized (vehicle battery voltage)
  • Position/speed sensor supply: typically battery/ignition-switched 12 V or reference 5 V (consult wiring diagram)
  • Position/speed sensor signal: typically 0–5 V analog or pulse train; should change smoothly as seat moves
  • Relay contact voltage to motor: ~12 V when relay closed
  • Motor current draw: varies by design (often 1–10 A); high current indicates seizure or binding
  • Resistance: relay coil resistance (ohms) and sensor resistance (if applicable) per service data

Diagnostic algorithm

  1. Retrieve and record DTC and freeze-frame data. Note related codes and events.
  2. Attempt to reproduce the fault (operate seat height) and observe symptom, listen for relay clicks.
  3. Visually inspect wiring, connectors, fuses and relay for corrosion, damage or water ingress. Repair as needed.
  4. With ignition on, probe relay socket: verify coil supply and ground when seat height command issued. If no coil voltage, check upstream control and fuse.
  5. Check relay contact output to motor when commanded. If coil energizes but no output, replace relay or inspect relay contacts and wiring.
  6. Measure position/speed sensor supply and signal while moving the seat. Signal should change smoothly; an open/short or noisy signal indicates sensor/harness issue.
  7. Measure motor current while operating seat. Excessive current suggests mechanical binding or a failing motor; near-zero current with relay energized suggests open wiring or motor failure.
  8. Perform continuity checks from the module/relay to the motor and sensor. Repair any opens/shorts found.
  9. If wiring, relay and motor/sensor check good, consider swapping with a known-good relay (if available) and re-test. If fault persists, evaluate the seat control/body control module per manufacturer procedures.
  10. After repairs, clear codes and verify the system works over multiple cycles. Re-scan to confirm no reoccurrence.

Likely causes

  • Corroded connector at seat height sensor or relay
  • Failed position motor relay (stuck/open or coil not energizing)
  • Broken or shorted wire in harness to sensor or relay
  • Seized height motor causing overcurrent or no movement
  • Sensor output out of range (open circuit or short to supply/ground)

Fault status

⚠️ Status
Seat height speed/position sensor or position motor relay circuit fault detected. Check sensor, relay, wiring, power and ground; possible mechanical fault in height motor.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1B86 B1B88 B1B89 B1B90 B1A16
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 .