B2250 — All Doors Unlock Relay Circuit Failure

What does OBD2 code B2250 mean?

All Doors Unlock Relay Circuit Failure (B2250): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by faulty switch, motor or actuator of the affected system, body control module (BCM) fault, corroded or loose connectors.

What is the most common cause of B2250?

The most common causes are: faulty switch, motor or actuator of the affected system, body control module (BCM) fault, corroded or loose connectors.

Will B2250 clear itself?

Sometimes B2250 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.

How do I diagnose B2250 myself?

Start with a scan: confirm B2250, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the all doors unlock relay circuit, and verify the suspect component against live data before buying parts.

How much does it cost to fix B2250?

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

When your vehicle's engine control module detects a problem in the door unlock relay circuit, it logs trouble code B2250. This is a body electrical fault rather than an engine issue, which means the powertrain itself usually continues operating normally. The module monitors voltage and ground signals at the unlock relay, and when those readings fall outside acceptable parameters for multiple drive cycles, B2250 gets stored alongside a freeze frame snapshot capturing engine speed, load, coolant temperature, and vehicle speed at the exact moment the failure occurred.

Understanding why B2250 triggers requires a quick look at how modern door lock systems work. The body control module coordinates locking and unlocking by energizing relays that direct power to the door actuators. When a switch is pressed, the BCM receives the signal and toggles the appropriate relay. If that relay fails electrically—through an open coil, welded contacts, or a broken feed—the circuit goes open and the module detects the abnormality immediately. The stored freeze frame helps you recreate the failure conditions during diagnosis, making troubleshooting more efficient.

Symptoms of B2250

The most obvious sign is a dashboard warning light, typically the check engine or body system indicator. In most cases, the engine runs and drives exactly as it should—the fault lives in the comfort and security side of the vehicle. Specific symptoms include one or more doors failing to unlock, intermittent operation where locks work sometimes and fail other times, or complete loss of the central locking function. Depending on which specific circuit shares the failing relay, you might also notice problems with windows, interior lighting, or wipers operating abnormally or not at all.

Common Causes

The unlock relay circuit can fail for several reasons. By far the most frequent culprit is a simple electrical failure within the relay itself—contacts corrode, coils open up, or solder joints crack from vibration and thermal cycling. A blown fuse in the same circuit produces identical symptoms, so that's always worth checking first. Wiring damage ranks second, particularly in the door jamb areas where flexing eventually breaks individual conductors while the harness insulation stays intact. Water intrusion accelerates both relay and wiring failures, which is why puddle-prone vehicles see these faults more often. The body control module can fail, though that's less common than peripheral component issues. Finally, a faulty door switch or worn actuator motor can draw excessive current and take out the relay or fuse upstream.

Diagnostic Procedure

Start by connecting a scan tool and pulling all stored codes. Confirm B2250 is present, then record the freeze frame data before clearing anything—this information reveals the driving conditions when the fault appeared. Next, search for any related body system codes; often the unlock circuit shares pathways with other functions, and those related codes point directly to the failing component. Check manufacturer TSB databases using your VIN, as many B0xxx series faults have published software corrections or known issues.

Visually inspect all connectors in the door unlock circuit. Pull each one apart and look for corrosion, bent pins, or moisture residue. Pay special attention to the driver's door harness where it flexes every time the door opens and closes—this is where broken wires hide. With the connectors still mated, monitor live data for the lock motor while commanding it on and off; voltage and current readings that sag or drop completely indicate a weak circuit. Replace the relay only after confirming the fuse is good and wiring checks out—swapping relays without verification wastes money if the problem lies elsewhere.

Repair Options and Costs

Once you've isolated the failure point, repair costs vary significantly depending on what needs fixing. The body control module itself runs $300 to $900 when replacement is necessary, though BCM repair shops sometimes offer board-level fixes at the lower end. Replacing a faulty door lock switch or actuator motor typically costs $120 to $450 per component. Wiring repairs fall between $80 and $250 depending on whether you need new connectors, splices, or a complete harness section.

The total bill to resolve B2250 generally lands somewhere between $80 and $900. Getting the diagnosis right before buying parts makes the biggest difference in your final cost. The cheapest possible fix—a bad fuse or corroded connector—costs under a hundred dollars, while full BCM replacement represents the maximum scenario. Work through the simple checks first and you'll almost certainly spend less than the worst-case estimate.

Can You Drive with B2250?

This fault rates as a low-severity issue for most drivers. Your engine, transmission, and brakes remain unaffected, so the vehicle stays fully drivable in normal conditions. The main exceptions involve safety-related systems: if the code affects exterior lighting, you're legally impaired at night or in poor visibility. Wiper failure during rain or snow creates a genuine hazard. Central locking that leaves doors unlocked or locks you out entirely presents a security concern. For purely cosmetic or convenience functions, drive normally but schedule repairs before these secondary problems escalate.

Related OBD2 Codes

• B2200: No Communication to TV Module (No Fitting of TV)
• B2201: No Communication With Traffic MasterModule
• B2202: No Communication to VICS Module (No Fitting of VICS)
• B2203: CD-ROM Error
• B2204: GPS Antenna Connection Open or Short
• B2205: GPS Receiver Error