B1726 — Seat Driver Rear Up Switch Circuit Open

How much does it cost to fix B1726?

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 does OBD2 code B1726 mean?

OBD2 code B1726 flags a problem with the body electrical system (seat driver rear up switch circuit open). The car is usually drivable while you plan the repair. Common culprits: damaged wiring in door jambs or wet areas, blown fuse or failed relay, faulty switch, motor or actuator of the affected system.

Will B1726 clear itself?

Sometimes B1726 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.

Is it safe to drive with B1726?

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 is the most common cause of B1726?

The most common causes are: damaged wiring in door jambs or wet areas, blown fuse or failed relay, faulty switch, motor or actuator of the affected system.

Your vehicle's body control module continuously monitors the electrical circuits that handle comfort and convenience features scattered throughout the cabin. B1726 gets triggered when the module expects to see a signal from the driver's seat rear up switch circuit but receives nothing at all. Instead of a normal voltage reading, the circuit shows an interruption—a complete break in the electrical path.

The driver's seat adjustment system relies on a series of switches, motors, and position sensors working together through the body control network. The rear up switch tells the module when you're trying to raise the rear portion of the seat cushion. When that circuit goes open, the module can't complete its diagnostic check and flags the fault after observing the condition for a set number of drive cycles. The stored freeze frame data captures engine RPM, load, temperature, and vehicle speed at the exact moment the problem first appeared, giving you a precise snapshot for troubleshooting.

A circuit open means electricity cannot flow through the expected path. This typically happens when a wire breaks somewhere along the harness, a connector comes loose or develops corrosion on its pins, a fuse blows in the feed circuit, or the switch itself fails internally and stops conducting. The module logs B1726 and illuminates the warning light once it confirms the fault persists across multiple ignition cycles.

Common Symptoms of B1726

• The rear up adjustment for the driver's seat does not respond when activated or works only intermittently
• The seat may also exhibit problems with other adjustment directions if wiring runs through the same area
• The check engine or body warning light remains illuminated on the dashboard
• Other comfort features sharing the same circuit—such as powered mirrors or lumbar adjustment—may also fail or behave erratically
• No changes occur in engine performance, fuel economy, or transmission behavior since the fault involves body electronics rather than drivetrain systems
• The seat may hold its current position but cannot be raised or adjusted using the affected controls
• Live data streams from the scan tool may show the switch status as stuck in one position or showing no response

What Causes B1726?

• A blown fuse or failed relay feeding voltage to the seat adjustment circuit
• A broken wire in the seat driver rear up switch harness, often near pinch points or moving components
• The seat driver rear up switch itself has failed internally and no longer completes the circuit
• A connector that is unplugged, has a backed-out terminal pin, or shows signs of corrosion blocking electrical contact
• Wiring insulation damaged by chafing against seat rails, door jambs, or wet areas prone to moisture intrusion
• A faulty motor or actuator controlling the seat adjustment mechanism
• The body control module itself has developed an internal fault affecting this circuit

How to Diagnose B1726

1. Connect an OBD2 scanner and verify that B1726 is stored as an active or pending code. Capture the freeze frame data—this shows what was happening with the engine when the fault first occurred and guides your inspection strategy.

2. Pull all stored diagnostic trouble codes from the module. Related codes often point to the underlying cause; for instance, multiple switch circuit codes might indicate a power supply problem rather than individual switch failures. Check manufacturer technical service bulletins for your specific make and model—some B1726 issues have documented factory fixes or software updates.

3. Perform a thorough visual inspection of the wiring harness and connectors associated with the seat adjustment circuit. Look for damaged insulation, corroded terminals, broken strands of wire, and any signs of water intrusion or prior repairs that may have been done incorrectly.

4. Use a multimeter to check continuity end-to-end on the seat driver rear up switch circuit. Apply light pressure while measuring to detect intermittent opens. Wiggle the harness at flex points—door jambs, seat tracks, and hinge areas—while watching for the resistance reading to fluctuate or spike.

5. Observe the switch input status in the scan tool's live data stream while an assistant operates the seat adjustment controls. The voltage or resistance should change predictably with each switch press; a flatline reading confirms the circuit is not responding.

6. Clear the code after your inspection and test drive, including conditions similar to those recorded in the freeze frame. If B1726 returns, the fault is confirmed and repairs will be necessary.

Repair Options and Costs

Addressing the most accessible and affordable possibilities first saves money and prevents unnecessary part replacements:

• Repair damaged wiring, replace corroded connectors, or fix loose terminals: $80–$250
• Replace the faulty seat driver rear up switch or associated actuator motor: $120–$450
• Body control module repair through a specialist or full replacement with programming: $300–$900

Total Repair Cost for B1726

The actual expense depends entirely on which component is responsible. Most independent shops charge between $80 and $900 for parts and labor combined. A methodical diagnostic approach identifies the root cause before you purchase replacement parts—the priciest scenario (BCM replacement) should never be your first assumption. Many B1726 faults trace back to nothing more than a blown fuse or loose connector.

Can You Drive with B1726?

In most cases, yes—body electrical faults rarely compromise engine operation or safety systems. The vehicle remains driveable, though the specific seat adjustment function will not work until repairs are made. The exception involves cases where the fault also affects exterior lighting, wipers in adverse weather, or central locking, which could create unsafe conditions. Use your judgment based on which features are affected, but there is no drivetrain risk.

Related OBD2 Codes

• B1700: B1700 — Seatbelt Passenger Pretensioner Circuit Short to Ground: Causes, Symptoms & Fix
• [B1701: Seat Driver Recline Forward Switch Circuit