B1736 — Mirror Driver Vertical Switch Circuit Short To Ground

B1736 — Mirror Driver Vertical Switch Circuit Short To Ground. A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: damaged wiring in door jambs or wet areas, body control module (BCM) fault, corroded or loose connectors.

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 B1736 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 B1736 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B1736 (parts and labor, USD, independent shop rates): Repair wiring or connectors: $80–$250; BCM repair or replacement: $300–$900; Replace the switch or actuator: $120–$450. Overall, fixing B1736 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

Will B1736 clear itself?

Sometimes B1736 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.

What does OBD2 code B1736 mean?

How much does it cost to fix B1736?

Repair wiring or connectors — $80–$250; BCM repair or replacement — $300–$900; 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 are the symptoms of B1736?

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

How do I diagnose B1736 myself?

Start with a scan: confirm B1736, 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 diagnostic system stores trouble code B1736, it's reporting a specific electrical fault in the driver's side mirror adjustment circuit. The code specifically points to the vertical (up and down) switch for the driver's mirror and indicates that the control module has detected an unintended path to ground where none should exist. In practical terms, the mirror switch circuit is essentially shorted to the vehicle's chassis ground, preventing the body control module from reading the switch input correctly.

The system at the center of this fault is the power mirror circuit managed by the body control module. When you press the mirror's up or down adjustment button, the BCM sends voltage through the switch to ground through the mirror motor, making it move. A short-to-ground condition means that somewhere in this circuit, the wiring or a component is making direct contact with ground before the switch command reaches its intended destination. The module monitors this circuit continuously during vehicle operation, and when sensor readings stay outside the expected parameters for the required number of drive cycles, it logs B1736 and turns on the appropriate warning light. The freeze frame data saved alongside the code captures the exact conditions at the moment of detection, which gives you valuable context for recreating the fault during diagnosis.

Understanding B1736 matters because mirror adjustment faults rarely appear in isolation. This code frequently shows up alongside other body system codes, which suggests the underlying issue might be broader than just the mirror switch. The good news is that body codes like B1736 generally do not impact engine performance or the vehicle's ability to drive safely, though they do point to an electrical system that needs attention.

Symptoms of B1736

The driver's side mirror fails to move vertically while horizontal adjustment continues working normally
The mirror adjustment switch may feel unresponsive or produce no result when pressed up or down
A dashboard warning light related to body systems illuminates after B1736 is stored
The fault may affect other functions sharing the same BCM circuit, including power windows, door locks, or interior lighting
Symptoms can be intermittent, with the mirror working correctly one moment and failing the next
The issue typically persists across multiple driving cycles until the underlying cause is addressed

Common Causes of B1736

Corrosion or looseness at the mirror switch connector or the door harness junction to the body
Chafed or broken wiring in the door jamb where flexing causes wire insulation to crack over time
A defective driver's mirror vertical adjustment switch with internally shorted contacts
Water intrusion into the mirror assembly or door panel causing moisture-related shorts
A faulty body control module unable to process switch inputs correctly
Blown fuse or failed relay that interrupts power to the mirror circuit

How to Diagnose B1736

Connect an OBD2 scanner and verify that B1736 is the primary stored code. Record all freeze frame data, paying close attention to vehicle speed, engine load, and temperature readings when the fault first appeared. This snapshot helps you recreate the exact conditions during test drives.
Look up any manufacturer technical service bulletins for your specific make, model, and year that reference B1736 or mirror adjustment faults. Factory-issued TSBs often document known issues with updated software calibrations or recommended repair procedures that save diagnostic time.
Perform a detailed visual inspection of the mirror switch, the mirror assembly wiring, and the door-to-body harness connector. Pull back any weatherstripping and examine the wiring entering the door hinge area, as this flex point is where wires most commonly suffer insulation damage from repeated opening and closing cycles.
Monitor live data from the mirror switch input on your scanner while physically operating the switch. The BCM should show the signal state changing as you press the up and down buttons. If the data never changes or shows an abnormal reading even with the switch disconnected, the problem lies in the wiring harness between the switch and module.
Test for short-to-ground conditions using a multimeter at the mirror switch harness with the switch disconnected. Measure resistance between the signal circuit and ground—you should see high resistance or OL (open loop) under normal conditions. A reading near zero ohms confirms a direct short to ground in the wiring.
Clear the code after your inspection and repair, then complete a full drive cycle that includes the conditions captured in the freeze frame data. Verify that B1736 does not return and that the mirror operates correctly before considering the diagnosis complete.

Repair Options for B1736

Addressing B1736 typically starts with the most accessible and affordable fixes before moving to component replacement. Cleaning and reseating the mirror switch connector runs about $30 to $75 including labor. Repairing damaged wiring or connectors in the door jamb area costs between $80 and $250 depending on the extent of the damage and whether trim panel removal is required. If the mirror switch itself is faulty, replacement parts and labor typically total $120 to $450 depending on the vehicle. Body control module repair or replacement is the most expensive scenario, ranging from $300 to $900 when both parts and professional labor are factored in.

Total Cost to Fix B1736

The actual repair cost for B1736 depends entirely on which component is responsible for the short-to-ground condition. Most vehicles will fall into one of the three main repair categories. Simple wiring or connector issues typically cost $80 to $250 to resolve. A failed mirror switch generally requires $120 to $450 for parts and labor. The body control module scenario represents the high end at $300 to $900. Independent shop labor rates average $80 to $150 per hour. An accurate electrical diagnosis before purchasing any parts is strongly recommended, as the least expensive repair is the correct one in the majority of B1736 cases.

Driving Safety Verdict

B1736 carries a short severity rating, meaning you can continue driving your vehicle while addressing this fault on your schedule. The mirror adjustment issue does not affect engine operation, transmission function, or braking systems. The main practical concern is reduced driver visibility if you cannot position the mirror correctly for your seating position. Exercise extra caution when changing lanes or reversing until you have confirmed that all mirrors are properly adjusted. The electrical fault itself will not cause drivability problems or leave you stranded.