B1503

Code

LAND ROVER B — Body

Right turn signal indicator - circuit failure

Brand: LAND ROVER

Type: B — Body

Views: UK: 16 EN: 45 RU: 25

AI status

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Page language: EN

Causes

Open or shorted wiring in the right turn signal circuit
Failed or burned-out bulb (incandescent) or failed LED module
Poor or corroded connector or ground
Blown fuse or faulty fusible link
Faulty Body Control Module (BCM) / instrument cluster driver
Aftermarket lamp or incorrect lamp load causing feedback errors

Symptoms

Right turn signal lamp does not illuminate (front or rear) when activated
Turn indicator warning on instrument cluster, possible rapid flashing (hyperflash) or no flash
DTC B1503 stored and may illuminate MIL or message on display
Intermittent operation or only works when wiring/connector is moved (wiggle symptom)

What to check

Confirm fault with a scan tool: read freeze frame, monitor lamp status and BCM outputs
Visually inspect right turn lamp, socket, connector, and wiring for damage or corrosion
Check related fuses and relays for continuity and proper seating
Measure voltage at the bulb/socket with turn signal ON (key ON, engine off acceptable)
Check continuity and resistance between bulb socket and BCM output and between socket ground and chassis
Swap known-good bulb or lamp assembly (or mirror/side repeater) to verify lamp type and operation

Signal parameters

Expected supply voltage: ~11–14 V with ignition ON and engine running
Bulb current (incandescent): typically 0.5–2.0 A; LED modules: 20–300 mA depending on design
Open-circuit: infinite resistance between bulb positive feed and BCM output; short to ground: near 0 Ω
Typical flash frequency: about 1–2 Hz (depends on vehicle/BCM)
Driver output: low-side or high-side switching depending on model—verify with service data

Diagnostic algorithm

Retrieve DTCs and freeze frame with a diagnostic scanner. Confirm B1503 is current or historic and clear codes to retest.
With turn signal selected RIGHT, observe lamp behavior and note hyperflash, no flash, or intermittent operation.
Visually inspect right turn lamp assembly, socket and harness for corrosion, damage, water ingress, or poor connection. Repair as needed.
Replace the bulb with a known-good bulb (or temporarily swap left/right) to exclude lamp failure. Re-test.
Check fuses and relays for the lighting circuit. Replace or reseat if suspect.
Back-probe the lamp positive feed and ground at the socket with a multimeter while activating the right turn signal. Confirm ~12 V at feed and good chassis ground. If voltage is absent, trace back toward BCM.
Check continuity and resistance from the socket to the BCM output pin and from socket ground to chassis ground. Repair any open/high-resistance circuits.
If short to ground or battery suspected, isolate sections of wiring and inspect harnesses for chafing, pinched areas, or water damage (common at doors, tailgate, rear quarter).
If wiring and lamp are good but no output present, use a scan tool to command the right indicator output from the BCM and measure the output. If BCM fails to command or measured output is abnormal, consult manufacturer service data for BCM/cluster testing and consider module replacement.
After repair, clear codes and retest multiple cycles of the turn signal to confirm fault does not return.

Likely causes

Right rear/side turn lamp burned out or LED module defective
Corroded lamp socket or damaged wiring near the lamp or hinge area
Loose or corroded ground at the lamp or chassis
Short to battery or to ground at lamp connector or intermediate splice
BCM output transistor or driver circuit failed for the right indicator
Blown fuse for lighting circuits or a poor fuse/relay contact

Fault status

⚠️ Status

B1503 — Right turn signal indicator circuit failure detected. Check lamp, wiring, connectors, fuses, and BCM driver.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-1.5 hours

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B1503 — Right turn signal indicator - circuit failure