B2150 — Power Supply #1 Circuit Short to Ground

OBD2 code B2150 flags a problem with the body electrical system (power supply #1 circuit short to ground). The car is usually drivable while you plan the repair. Common culprits: damaged wiring in door jambs or wet areas, body control module (BCM) fault, faulty switch, motor or actuator of the affected system.

body electrical

Is it safe to drive?

Short-term driving is OK Usually safe to drive — body codes rarely affect drivability. Exceptions: exterior lighting and wipers in bad weather, and central locking faults that can leave the car unsecured.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm B2150 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many B0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the body electrical system for damage, corrosion, chafing or poor contact.
Subsystem check Operate the affected function while watching its switch and motor PIDs in live data.
Subsystem check Inspect connectors and wiring at flex points (door jambs, tailgate hinges) — wires break there first.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm B2150 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B2150 (parts and labor, USD, independent shop rates): BCM repair or replacement: $300–$900; Replace the switch or actuator: $120–$450; Repair wiring or connectors: $80–$250. Overall, fixing B2150 usually costs between $80 and $900. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What are the symptoms of B2150?

Drivers most often notice: no impact on engine operation in most cases, the affected function (locks, windows, lighting, wipers) works intermittently or not at all, warning light on the dashboard.

Is it safe to drive with B2150?

Usually safe to drive — body codes rarely affect drivability. Exceptions: exterior lighting and wipers in bad weather, and central locking faults that can leave the car unsecured.

What does OBD2 code B2150 mean?

What is the most common cause of B2150?

The most common causes are: damaged wiring in door jambs or wet areas, body control module (BCM) fault, faulty switch, motor or actuator of the affected system.

How do I diagnose B2150 myself?

Start with a scan: confirm B2150, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the body electrical system, and verify the suspect component against live data before buying parts.

When your vehicle's body control module detects that Power Supply #1 is dropping to ground unexpectedly, it logs trouble code B2150. This is a body electrical fault, meaning the issue lives in the circuits that run your door locks, windows, lighting, wipers, and similar accessories. The ECU does not set B2150 off a single bad reading. Instead, it watches the condition repeat under specific operating parameters before triggering the check engine light or body module warning. That built-in confirmation loop keeps you from chasing ghost codes.

Understanding what Power Supply #1 actually supplies helps you narrow the problem fast. That circuit feeds one specific group of accessories through the body control module. When something pulls that supply rail to ground — either a short in the wiring or a failed component drawing current the wrong way — the module flags B2150. The freeze frame data stored alongside the code tells you engine load, RPM, coolant temperature, and vehicle speed at the moment the fault appeared. Replicating those exact conditions during testing is the key to catching an intermittent problem.

Symptoms of B2150

The fault typically does not affect engine performance or drivability in most vehicles
The accessory circuit connected to Power Supply #1 operates erratically or stops working entirely (door locks, windows, interior lighting, wipers, or other body functions depending on your make)
A warning light or indicator appears on the instrument cluster
Symptoms may come and go, especially if the underlying issue is moisture-related or vibration-induced
The affected system may work normally until specific conditions are met, then fail again

Common causes of B2150

Corroded or loose electrical connectors in the body harness, particularly in areas exposed to moisture
Damaged wiring insulation in door jambs, tailgate hinges, or other flex points where wires bend repeatedly
A faulty switch, window motor, lock actuator, or other load device on the affected circuit
Body control module itself has failed or developed an internal short
Blown fuse or failed relay feeding Power Supply #1 to the BCM

How to diagnose B2150 step by step

Plug in an OBD2 scanner and retrieve all stored codes. Confirm B2150 is present, then save the freeze frame data — this snapshot shows engine load, RPM, coolant temperature, and vehicle speed at the exact moment the module detected the fault.
Review any related trouble codes stored at the same time. Codes in the B0xxx range often point to the specific circuit or component that caused the short, and checking manufacturer TSBs for your vehicle may reveal a known issue or software fix.
Perform a hands-on visual inspection of the wiring harness and connectors tied to the body electrical system. Look for worn insulation, broken strands, corrosion, bent pins, or connectors that are not fully seated.
Operate the suspected affected function while monitoring live data. Watch switch state and motor/actuator PIDs on your scanner to see whether the command and feedback signals match what you expect.
Pay close attention to flex points — the passages where wiring runs through door jambs and around hinges. These areas flex every time you open and close the door, and broken strands here are a frequent source of intermittent shorts.
Clear the code, then drive the vehicle through a complete drive cycle that reproduces the freeze frame conditions. If B2150 returns, you have confirmed an active fault and can rule out a one-time electrical glitch.

Repair options and costs for B2150

Work from the simplest and cheapest possibilities toward the expensive components.

Wiring and connector repair — Fixing chafed wires, replacing damaged connectors, or sealing corroded terminals typically runs $80–$250 depending on labor time and whether splice connectors or new harness sections are needed.
Switch or actuator replacement — If a faulty window motor, lock actuator, or switch is pulling the circuit to ground, replacing the failed component costs $120–$450 for parts and labor.
BCM repair or replacement — When the body control module itself is the culprit, repair or swap ranges from $300–$900 depending on whether the module can be rebuilt or must be replaced with a new or refurbished unit.

Total repair cost for B2150 generally falls between $80 and $900. A methodical diagnosis that rules out wiring and connector problems before replacing the BCM will keep your bill at the lower end of that range. Parts pricing varies by make and model, and dealer labor rates sit higher than independent shop rates.

Can you keep driving with B2150?

B2150 is classified as short-term safe to drive. Body electrical faults rarely interfere with engine operation, transmission function, or braking. That said, the exceptions are worth noting. If Power Supply #1 feeds your exterior lighting, wipers, or central locking, those functions may be inoperative or unreliable. Driving at night with no headlights or through a storm with broken wipers creates a safety hazard of its own. Address the underlying fault promptly, even if the engine runs fine.