B140A

Code

LAND ROVER B — Body

Flat seat fold switch

Brand: LAND ROVER

Type: B — Body

Views: UK: 9 EN: 14 RU: 7

AI status

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Page language: EN

Causes

Failed or intermittent flat seat fold switch
Damaged wiring harness (open, short to ground or power)
Corroded or loose connector at the switch
Poor ground or supply at the switch
Water ingress or contamination in switch/connector
Faulty body control module (rare) or module software issue

Symptoms

Seat fold function inoperative or intermittent
No response when using flat/seat fold switch
Related warning or message on dash (seat stowed error)
DTC B140A stored in diagnostic module
Possible LED/indicator for seat fold not illuminating

What to check

Retrieve freeze-frame and full DTC list with a diagnostic scanner; note related codes
Visual inspection of switch, seat area and wiring for damage, corrosion or water
Check related fuses and relays for continuity and correct operation
Wiggle test wiring while operating switch to reproduce fault
Measure supply voltage and ground at the switch connector with ignition on
Check switch terminal continuity/resistance while operating switch

Signal parameters

Switch supply: typically battery voltage with ignition/accessory on (approx. 11–14 V)
Switch output: toggles between near battery voltage and open/ground depending on design
Closed switch: low resistance (close to 0 Ω between relevant terminals)
Open switch: high resistance / open circuit
Intermittent: fluctuating voltage or inconsistent continuity when actuated

Diagnostic algorithm

Connect a diagnostic scanner, confirm B140A and any other related codes; record freeze-frame data.
Attempt to reproduce the fault while observing switch operation and any dash messages.
Perform a visual inspection of the switch, connector and visible wiring for damage, corrosion or water entry. Repair any visible wiring damage.
Check fuses and supply: with ignition on, verify battery voltage at the switch power terminal (approx. 11–14 V). Repair supply issues if absent.
Check ground: verify good chassis ground at switch connector. Clean/tighten grounding if needed.
Test switch continuity: disconnect connector and measure resistance between switch terminals while operating the switch (closed = near 0–5 Ω; open = OL or very high).
Back-probe signal circuit: observe voltage change at the signal terminal when actuating the switch. Look for stable transitions to/from expected voltage/ground.
If wiring appears intact but signal not reaching module, perform continuity check from switch connector to module connector; repair shorts/opens as found.
If wiring and switch test good, check for module input faults or software updates. Reprogram or replace module only after confirming wiring and switch condition.
Replace the switch if it fails bench/vehicle tests. Clear codes and road-test / operate seat fold several cycles to confirm repair. Re-scan to ensure code does not return.

Likely causes

Faulty switch or internal contacts worn/fouled
Connector corrosion or pin damage at seat switch
Broken or chafed wire in harness where it flexes
Blown fuse or loss of supply/ground to switch
Intermittent wiring due to water ingress

Fault status

⚠️ Status

Flat seat fold switch circuit fault detected (B140A).

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-1.5 hours

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Repair manuals

Manual library for LAND ROVER

413

Browse 413 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

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