B1644 — Mirror Passenger Right Circuit Open

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 B1644 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 Do a continuity test end-to-end on the mirror passenger right circuit and wiggle the harness while measuring — intermittent opens show up as fluctuating readings.
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 B1644 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B1644 (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 B1644 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

Is it safe to drive with B1644?

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 much does it cost to fix B1644?

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.

What are the symptoms of B1644?

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.

What does OBD2 code B1644 mean?

Mirror Passenger Right Circuit Open (B1644): a body electrical fault affecting the body electrical system. The car is usually drivable while you plan the repair. Most often caused by corroded or loose connectors, faulty switch, motor or actuator of the affected system, blown fuse or failed relay.

Will B1644 clear itself?

Sometimes B1644 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.

When your vehicle's body control module logs code B1644, it has detected an open circuit condition in the passenger-side mirror system. This is a body electrical fault, not an engine or drivetrain issue. The term "open" describes a break in the electrical pathway — current simply cannot flow through the circuit the module expects to find working. That broken path could be a severed wire, a connector that has come apart or suffered corrosion at its pins, a blown fuse, or a mirror assembly with an internal failure. The key point is that something physical is preventing electricity from reaching or returning from the passenger mirror.

The body control module does not set this code after a single bad reading. Automotive ECUs are designed to confirm faults across multiple drive cycles before triggering the malfunction indicator lamp. When B1644 is stored, the freeze frame data captures the vehicle's operating conditions at the moment of failure — engine load, RPM, coolant temperature, and vehicle speed. That snapshot tells you exactly what circumstances to reproduce when you begin testing. Use it. If the code set at 60 mph with the engine at operating temperature, you need those same conditions to confirm whether your repair actually resolved the issue.

Common Symptoms

The passenger mirror fails to adjust in any direction or remains frozen in one position
Heated mirror function (if equipped) stops working
The malfunction indicator lamp may illuminate on the instrument cluster
Engine performance and drivability are unaffected in most cases
Other body electrical functions — locks, windows, other mirrors — typically continue operating normally
In some instances, the problem manifests intermittently before becoming constant

What Causes B1644?

A broken or chafed wire within the passenger mirror harness (the most frequent culprit)
A loose, backed-out, or corroded electrical connector at the mirror assembly or BCM
A blown fuse dedicated to the mirror circuit
An internally failed mirror motor or heating element
Damage to wiring at flex points such as the door jamb, where wires bend repeatedly
A faulty body control module that fails to properly manage the circuit
Water intrusion causing corrosion on connectors or terminals in wet areas

How to Diagnose B1644

Connect an OBD2 scanner and verify that B1644 is present. Record the freeze frame data before clearing anything — you will need those conditions to validate any repair.
Scan for any other body-related trouble codes. Related codes frequently point to the underlying cause, such as a shared power supply or ground issue affecting multiple circuits.
Perform a thorough visual inspection of the wiring harness and connectors tied to the passenger mirror. Look for damaged insulation, burn marks, broken strands, and any sign of moisture or corrosion.
Use a multimeter to check continuity end-to-end on the mirror circuit. Apply light pressure and gently wiggle the harness during testing — an intermittent open will show up as fluctuating resistance or an outright open reading.
Operate the mirror switch while monitoring voltage and ground at the mirror connector. This tells you whether the BCM is sending the correct signals and whether the problem lies upstream or within the mirror itself.
Examine connectors and wiring at door hinge areas and any other flex points. These locations endure constant movement and are where wires most commonly fail from fatigue.
Clear the code, then drive the vehicle through a complete drive cycle that reproduces the freeze frame conditions. If B1644 returns, the fault is still present.

Repair Options

Depending on the root cause, here is what you can expect to spend on parts and labor at an independent repair shop:

Repair damaged wiring or clean/replace connectors: $80–$250
Replace the mirror switch or mirror actuator motor: $120–$450
Repair or replace the body control module: $300–$900

Always address the least expensive and most common possibilities first. In the vast majority of cases, B1644 stems from a wiring issue or a loose connector — not a failed BCM.

How Much Does It Cost to Fix B1644?

The total bill hinges entirely on which component is actually responsible. Body control module work sits at the high end of the range, while connector repairs or wire splices represent the low end. Most repairs for this code fall between $80 and $900. Spending time on proper diagnosis before purchasing parts is the smartest move — the most expensive scenario is rarely the first place to look.

Can You Drive with B1644?

B1644 does not affect engine operation, so the vehicle remains mechanically drivable. Body electrical codes typically pose no direct threat to the drivetrain. That said, a nonfunctional passenger mirror reduces rearward visibility, which matters when changing lanes or backing up. If the fault involves exterior lighting or wipers, weather conditions become a genuine safety concern. Address this code before long highway trips or poor weather.