B1A58

Code

LAND ROVER B — Body

front control excitator seat relay failure

Brand: LAND ROVER

Type: B — Body

Views: UK: 3 EN: 5 RU: 4

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty front control excitator seat relay (stuck, burned contacts, open coil)
Blown fuse protecting the seat relay circuit
Open, shorted or corroded wiring between relay, seat actuator and control module
Poor or corroded connector or ground at relay or seat module
Faulty body/control module (BCM) driver transistor or relay driver circuit
Water ingress or mechanical damage to relay or seat wiring

Symptoms

Front seat excitator/actuator does not operate (no vibration/massage/actuation)
Intermittent seat excitator operation or only operates sometimes
Audible clicking from relay socket or no click when commanded
Seat stuck in one position or function unavailable
Malfunction indicator or information message on dash and stored DTC

What to check

Visually inspect relay, relay socket and associated fuse(s) for damage or corrosion
Check for water ingress or physical damage in seat area and harness
Use a scan tool to read the fault, attempt to command the seat excitator and watch live data/relay state
Swap the relay with a known-good same-type relay (if available) to see if function is restored
Inspect and tug-test connectors for corrosion, bent pins or poor contact
Check ground integrity at relay and seat module ground points

Signal parameters

Relay coil supply (battery feed): ~11–14 V (key on)
Switched relay output (to seat excitator): ~11–14 V when relay energized
Relay coil resistance (typical): ~50–200 Ω (manufacturer variation possible)
Control side: BCM/seat module command should provide ground or switch signal to energize coil when requested
No PWM/frequency expected for a simple on/off relay (steady DC when energized)

Diagnostic algorithm

Record freeze frame and all related codes with a diagnostic scanner; note conditions when code set.
Visually inspect relay, socket, fuse(s) and wiring for damage, corrosion or water ingress.
Check the fuse(s) protecting the seat relay circuit; replace if blown and retest.
Using the scan tool, command the seat excitator/relay ON while listening for relay click and observing live data.
Measure battery voltage at relay feed terminal (should be ~12 V).
With command active measure voltage at relay switched output to seat; if 12 V present at relay output but not at seat, suspect harness/connector fault.
Measure relay coil resistance (with relay removed) and verify the BCM control side produces the expected ground/drive when commanded.
Swap in a known-good relay of the same type to confirm relay fault if present.
Check continuity and insulation of wiring between relay and seat excitator; repair any opens/shorts and clean corroded connectors.
Verify and restore good grounds at relay and seat module.
If wiring and relay check good but control signal from BCM is absent or inconsistent, test BCM driver output and consider module reprogramming or replacement per manufacturer guidance.
Clear codes and re-test all functions; road-test or cycle power to ensure fault does not return.

Likely causes

Relay coil open or contacts burned (relay failure)
Blown fuse feeding the relay
Corroded connector or poor ground at relay socket
Open/short in harness to front seat excitator/actuator
BCM/seat module driver output failed

Fault status

⚠️ Status

Front control excitator seat relay failure — the relay or its switching circuit failed to operate or provide expected feedback. May be caused by relay, fuse, wiring/connectors, or controlling module driver fault. DTC stored when command-output mismatch or no relay activation detected.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

Your experience will help others

+100 karma for a short comment :)

Was this AI description helpful?

Your feedback helps improve AI descriptions.

👍 Like 0 👎 Dislike 0

Send to email