B1321

Code

LAND ROVER B — Body

Exit from ambient lighting zone 3

Brand: LAND ROVER

Type: B — Body

Views: UK: 17 EN: 22 RU: 21

AI status

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Page language: EN

Causes

Open or short in the ambient lighting harness for zone 3
Faulty ambient lighting lamp/LED module or LED string in zone 3
Poor power or ground connection to the lighting zone or control module
Corroded/damaged connector or water ingress at lamp or harness
Faulty body control / lighting control module or driver transistor
Incorrect module programming or lost configuration after battery disconnect

Symptoms

Ambient/accent lighting for zone 3 is dim, off or flickering
Warning message or DTC present in diagnostic scan tool
Inconsistent brightness or zone behaves differently after door open/close
Other ambient lighting zones function normally (isolated to zone 3)

What to check

Use a diagnostic scanner to read B1321 and any related codes; note freeze-frame/live data
Visually inspect lamp/trim area for water, damage or loose connectors in zone 3
Check related fuses and relays for the interior lighting/BCM circuits
Backprobe power and ground at the lamp/LED module with connectors connected and check for stable 11–14 V supply and good ground
Inspect wiring harness for damage, pin corrosion, chafing where it passes through body panels or doors
Check module coding/software level and look for Technical Service Bulletins (TSBs) or software updates

Signal parameters

Expected supply voltage at lamp/driver: ~11–14 V (with ignition/accessory on)
Ground continuity: low resistance to battery negative (
Typical LED segment current: 20–500 mA per segment depending on design (use wiring diagram for exact values)
Control signal often PWM from BCM — frequency commonly 100–1000 Hz (refer to vehicle wiring/tech data)
CAN bus idle differential ~2.5 V each line (verify communication present if lighting controlled via CAN)

Diagnostic algorithm

Connect a capable scan tool, record B1321 and any related codes, note freeze-frame data and live parameters for ambient lighting.
Clear codes, reproduce the condition (cycle ignition/doors) and see if code returns; if intermittent, attempt to wiggle harness to reproduce.
Visual inspection: check the zone 3 lamp, surrounding trim, connector and harness for damage or moisture.
Verify fuses/relays for interior/ambient lighting circuits and check for proper supply voltage at fuse box.
With ignition on, backprobe the power and ground pins at the zone 3 lamp/LED module; confirm ~11–14 V and good ground. Measure current draw if possible and compare to expected values from wiring data.
If power/ground are OK, monitor the control/PWM signal from the BCM to the lamp; if absent or abnormal, check BCM outputs and communications (CAN/LIN).
Disconnect the lamp/LED module and measure the output from the BCM for open/short conditions (be careful to follow manufacturer service procedures).
If wiring and lamp check OK, perform BCM module diagnostics: check for software updates, reflash or reconfigure, and verify internal driver outputs. Replace the lamp/LED module or repair wiring as indicated.
After repairs, clear codes and verify system operation across cycles (doors, ignition) to confirm repair.

Likely causes

Damaged wiring or connector at the lamp/door/trim where zone 3 is located
Failed LED lamp or LED driver inside the trim module for zone 3
Loose or corroded ground or power feed at fuse/relay or connector
Moisture ingress causing intermittent short/open in the zone 3 circuit
Software/configuration fault in the body control module

Fault status

⚠️ Status

Ambient lighting — Exit from ambient lighting zone 3 detected (zone 3 control/feedback fault).

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5 - 2.0 hours

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B1321 — Exit from ambient lighting zone 3