B1659 — Seat Driver Front Up Circuit Failure

B1659 — Seat Driver Front Up Circuit Failure. 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, faulty switch, motor or actuator of the affected system, blown fuse or failed relay.

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 B1659 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 B1659 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B1659 (parts and labor, USD, independent shop rates): Repair wiring or connectors: $80–$250; Replace the switch or actuator: $120–$450; BCM repair or replacement: $300–$900. Overall, fixing B1659 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 B1659?

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 B1659 mean?

What is the most common cause of B1659?

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

Will B1659 clear itself?

Sometimes B1659 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 are the symptoms of B1659?

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

When your scan tool retrieves code B1659, it tells you the body control system has detected a fault in the driver seat upward-adjustment circuit. This is a body-electrical problem, not an engine or powertrain issue. The control module continuously monitors voltage and ground paths for the seat motor that moves your seat up and down; when the signal falls outside expected parameters, the module logs B1659 and illuminates a warning light.

The seat adjustment system relies on a motor, a switch, and wiring that connects them to the body control module. When you press the "up" button, the switch sends a request to the module, which then energizes the motor. The module watches this loop for proper operation. If it sees an open circuit, a short, or resistance that doesn't match the calibration, B1659 gets set—typically across multiple drive cycles to rule out transient glitches. The stored freeze-frame data captures engine RPM, load, coolant temperature, and vehicle speed at the moment of failure, which helps you recreate the conditions during testing.

Common symptoms of B1659

The driver's seat fails to move upward when you activate the switch, or moves only intermittently
The seat may move in other directions but not up, indicating a circuit-specific failure
A dashboard warning light appears after the fault is detected
No changes to engine performance, transmission function, or braking systems
In some cases, adjacent seat functions (forward/back or recline) continue to operate normally

What causes B1659?

Damaged wiring or connectors in the seat adjustment circuit, especially in high-flex areas under the seat or in the door sill
A failed seat adjustment switch that no longer completes the control signal
A burned-out seat motor windings or seized motor mechanism
Corrosion or moisture intrusion at electrical connectors, common in vehicles with carpet spills or high humidity exposure
A faulty body control module that misinterprets valid signals or fails to supply power to the motor circuit
A blown fuse or failed relay that supplies voltage to the seat adjustment circuit

How to diagnose B1659

Connect an OBD2 scanner and confirm B1659 is stored in the body control module. Save the freeze-frame data—this snapshot shows what the engine was doing when the fault first appeared and guides your road test later.
Pull all related codes from the same module. Codes for adjacent seat functions or other body systems often point to a shared wiring problem or a failing module.
Search for TSBs specific to your make, model, and year using the manufacturer's website or NHTSA database. Many B-series codes have documented factory fixes or software calibrations.
Visually trace the seat wiring harness. Focus on the floor area under the seat where harness flexing occurs, and check connectors for pushed pins, corrosion, or broken wires.
Test the seat switch with a multimeter for continuity when pressed, and verify the motor's resistance is within specification if accessible.
Clear the code, operate the seat through a complete adjustment cycle, and road-test under conditions matching the freeze frame to confirm the fault does not return.

How to fix B1659

Address the least expensive components first to avoid unnecessary spending:

Repair frayed wiring or corroded connectors — typically $80–$250
Replace the seat adjustment switch or motor assembly — typically $120–$450
Repair or replace the body control module — typically $300–$900

How much does it cost to fix B1659?

Final cost depends on which part is actually at fault. Here are common repair scenarios at independent shop rates (parts and labor, USD):

Wiring repair or connector replacement: $80–$250
Switch or motor replacement: $120–$450
BCM diagnosis, repair, or replacement: $300–$900

Across all scenarios, expect to spend between $80 and $900 to resolve B1659. The most likely culprit is wiring or connectors, not the expensive module, so a thorough diagnosis before purchasing parts will keep your total bill low.

Can you drive with B1659?

Yes—B1659 generally poses no drivability risk. Your engine, transmission, and brakes remain unaffected. The main inconvenience is a non-adjustable seat and an illuminated warning light. Address the fault before extended trips if your seating position is compromised.