OBD Code B1336: Door Ajar RR Circuit Open

Q: What does OBD code B1336 mean?

Door Ajar RR Circuit Open. The rear right door's position sensor circuit is broken or disconnected, so the vehicle can't tell if that door is open or closed. It's like a light switch with a cut wire—the signal never reaches the control module.

Q: What are the symptoms of fault code B1336?

Door ajar warning light stays on continuously, Interior dome light may not function properly with door open/close, Vehicle may not lock or unlock rear right door remotely

Q: How do I fix OBD fault code B1336?

Inspect and reseat the connector at the rear right door latch for corrosion or loose pins.. Check the wiring between the door and body frame for cuts, pinches, or damaged insulation.. Replace the faulty latch switch if continuity tests confirm internal switch failure.

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What This Actually Means

In plain language — no jargon

The rear right door's position sensor circuit is broken or disconnected, so the vehicle can't tell if that door is open or closed. It's like a light switch with a cut wire—the signal never reaches the control module.

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Symptoms You May Notice

3 known symptoms for this code

Door ajar warning light stays on continuously

Interior dome light may not function properly with door open/close

Vehicle may not lock or unlock rear right door remotely

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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The body control module monitors the rear right door latch switch, which should toggle between open and closed circuit states. The ECU expects a valid voltage signal (typically 0V when closed, 12V when open) and flags a fault when the circuit remains open with no valid signal detected.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Door latch signal voltage	0V (closed) or 12V (open)	No signal or intermittent connection detected
Circuit continuity	Complete circuit with resistance <10 ohms	Open circuit with infinite resistance

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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex

1

Door latch switch connector

Inspect and reseat the connector at the rear right door latch for corrosion or loose pins.

2

Door latch wiring harness

Check the wiring between the door and body frame for cuts, pinches, or damaged insulation.

3

Door latch switch assembly

Replace the faulty latch switch if continuity tests confirm internal switch failure.

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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code B1336 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 B1336

What happens after you fix the fault

Once the fault is repaired, B1336 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.