B1505

Lamp Turn Signal Right Circuit Short To Battery

Body Chassis/Safety Turn Signal Lamp 🟢 Low — Fix at next service ✅ Safe to Drive
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What This Actually Means

In plain language — no jargon

The right turn signal lamp circuit is shorted directly to battery power, causing excessive current flow. Think of it like a wire touching the positive terminal of a battery—electricity flows where it shouldn't, triggering the fault.

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Symptoms You May Notice

3 known symptoms for this code
Right turn signal lamp stays on continuously or is abnormally bright
Turn signal does not flash or flash pattern is erratic
Possible blown fuse or burnt wiring smell near the lamp circuit
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The body control module monitors the turn signal lamp circuit voltage and current draw. It expects a specific voltage drop and current pulse pattern when the turn signal is activated. A short to battery causes the voltage to remain high and current to exceed normal limits, triggering the fault code.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
Lamp circuit voltage 0V (off) or 12V with controlled current draw when activated Constant 12V+ with excessive current draw indicating direct battery short
Current draw 0.5–2.0 A during normal operation >2.0 A sustained or continuous draw
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
Fuse for turn signal circuit
Replace the blown fuse with the correct amperage rating to isolate the fault temporarily and prevent component damage.
2
Wiring harness and connectors
Inspect the right turn signal wiring from the switch to the lamp for damaged insulation, exposed wires, or loose connectors touching ground or power.
3
Right turn signal lamp assembly
Replace the lamp unit if the internal socket or wiring is damaged and shorted to the housing or power contact.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code B1505 is a low-severity fault. Your vehicle is generally safe to drive to a workshop for diagnosis. However, do not ignore it indefinitely — low-severity codes often indicate developing problems that become expensive if neglected. Book a diagnostic appointment within 2–4 weeks. If you notice any additional symptoms (rough running, power loss, unusual smells), treat it as higher priority.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.
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How to Clear Code B1505

What happens after you fix the fault

Once the fault is repaired, B1505 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.

The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.

✅ Safe to Clear When
  • Fault has been diagnosed and repaired
  • You want to confirm the repair worked
  • Code appeared after a sensor was cleaned
⚠️ Do Not Clear When
  • Preparing for an emissions/PUC test
  • Root cause is still undiagnosed
  • Check engine light is flashing
Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.