B1336 — Door Ajar RR Circuit Open

How do I diagnose B1336 myself?

Start with a scan: confirm B1336, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the door ajar RR, and verify the suspect component against live data before buying parts.

What is the most common cause of B1336?

The most common causes are: blown fuse or failed relay, faulty switch, motor or actuator of the affected system, corroded or loose connectors.

How much does it cost to fix B1336?

BCM repair or replacement — $300–$900; Repair wiring or connectors — $80–$250; Replace the switch or actuator — $120–$450. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

What does OBD2 code B1336 mean?

OBD2 code B1336 flags a problem with the body electrical system (door ajar RR circuit open). The car is usually drivable while you plan the repair. Common culprits: blown fuse or failed relay, faulty switch, motor or actuator of the affected system, corroded or loose connectors.

Will B1336 clear itself?

Sometimes B1336 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

The right rear door might seem like a simple component, but it actually plays a role in your vehicle's body electrical system. Code B1336 indicates that the Body Control Module has detected an open circuit in the right rear door ajar circuit. In plain terms, the module is expecting to see a specific electrical signal from that door, but the signal never arrives because the circuit is broken somewhere along the path.

When you close a door, a small switch inside the latch tells the BCM that the door is shut. When you open it, the switch changes state. The BCM uses this information to control things like interior lighting, the security system, and door lock feedback. If the circuit feeding that switch goes open—meaning current cannot flow through it—the module logs B1336 and illuminates the check engine light (or a dedicated body fault indicator, depending on your vehicle). The module typically confirms this failure across multiple drive cycles before storing the code, which helps prevent false triggers from temporary electrical glitches.

The freeze frame data stored alongside B1336 is worth reviewing before you start tearing into wiring. That snapshot captures engine RPM, load, coolant temperature, and vehicle speed at the exact moment the fault was confirmed. If those conditions point to a specific scenario—like the vehicle being parked in cold weather with the door open—your diagnosis narrows considerably. Skipping this step often leads to replacing parts that were never actually faulty.

Symptoms of B1336

• Dashboard warning light or body module indicator turns on
• Engine performance remains unaffected in most vehicles
• Intermittent or complete loss of the associated function (power locks, windows, interior lighting, or wipers depending on how the circuit is used)
• Door ajar warning may stay lit even when all doors are properly closed
• Interior lights may fail to activate when the right rear door opens

Common Causes of B1336

• Blown fuse protecting the door ajar circuit — the most frequent culprit
• Broken or severed wire within the right rear door harness, especially near hinges or in the door jamb
• Connector pins that are backed out, unplugged, or corroded from moisture intrusion
• Internally failed door ajar switch inside the latch mechanism
• Wiring damaged by chafing against metal edges or degraded by exposure to wet conditions
• Faulty switch, actuator motor, or related component on the affected circuit
• Body Control Module itself malfunctioning or losing ground

How to Diagnose B1336

1. Connect an OBD2 scanner and verify that B1336 is stored. Save the freeze frame data before clearing anything — that record often points directly to the root cause when reviewed against the conditions present during your test drive.
2. Pull all related body electrical codes as well. A pattern of multiple B-codes may indicate a BCM power or ground issue rather than a problem isolated to the door circuit.
3. Visually inspect the wiring harness running to the right rear door. Focus on the door jamb pass-through where wires flex every time the door opens and closes. Look for cracked insulation, broken strands, and any signs of moisture damage or corrosion.
4. Perform a continuity test on the door ajar circuit from the BCM connector to the switch. With the meter connected, gently wiggle the harness—intermittent opens will show up as fluctuating resistance readings.
5. Check the switch itself for proper operation. Many door ajar switches can be accessed without removing the door panel; verify it reads closed when the door is shut and open when the door is cracked.
6. Inspect all connectors in the circuit for spread terminals, bent pins, or greenish corrosion buildup. Clean or repair as needed before reassembly.
7. Clear B1336, complete a drive cycle that recreates the freeze frame conditions, and verify the code does not return.

Repair Options and Pricing

Costs vary depending on which component is actually at fault. Here are typical scenarios at independent shop labor rates:

• BCM repair or replacement: $300–$900. BCMs sometimes fail outright, but many purported module failures turn out to be wiring or ground issues instead.
• Wiring or connector repair: $80–$250. Soldering a broken wire or replacing a corroded connector is usually straightforward if the damage is accessible.
• Door ajar switch or actuator replacement: $120–$450. The switch inside the door latch is a common failure point and relatively inexpensive to replace.

Total Cost to Fix B1336

Across all repair scenarios, expect to spend between $80 and $900. The wide range reflects how dramatically the cost changes depending on whether you need a simple fuse replacement or a full BCM swap. Professional diagnosis before purchasing parts almost always saves money—replacing expensive modules when the actual problem is a $5 fuse is an all-too-common mistake.

Can You Drive with B1336?

Generally safe to continue driving. Body electrical codes like B1336 rarely affect engine operation, transmission function, or braking systems. That said, if the fault impacts exterior lighting, wipers, or central locking, you may want to address it promptly to avoid driving in reduced visibility or leaving the vehicle unsecured.