B1660 — Seat Driver Front Up Circuit Open

OBD2 code B1660 flags a problem with the body electrical system (seat driver front up circuit open). The car is usually drivable while you plan the repair. Common culprits: blown fuse or failed relay, 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 B1660 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 seat driver front up 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 B1660 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B1660 (parts and labor, USD, independent shop rates): BCM repair or replacement: $300–$900; Repair wiring or connectors: $80–$250; Replace the switch or actuator: $120–$450. Overall, fixing B1660 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 B1660?

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.

Will B1660 clear itself?

Sometimes B1660 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 is the most common cause of B1660?

The most common causes are: blown fuse or failed relay, body control module (BCM) fault, corroded or loose connectors.

How do I diagnose B1660 myself?

Start with a scan: confirm B1660, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the seat driver front up, and verify the suspect component against live data before buying parts.

What does OBD2 code B1660 mean?

When your scan tool retrieves code B1660, it's reporting a specific fault within your vehicle's body electrical system: the driver seat up circuit has been detected as open. This falls under the B-series codes, which cover body control and comfort systems rather than engine management. The body control module (BCM) or a related control unit monitors this circuit constantly, and when it finds an unexpected break in the electrical path, it logs B1660.

An "open circuit" simply means current cannot flow through the expected pathway. In practice, this could stem from a severed wire, a connector that has backed out or corroded, a blown fuse, or a failed component like a switch or motor within the seat adjustment system. The module does not set the code instantly—it observes the condition across multiple drive cycles before confirming a genuine fault, which helps prevent false triggers from temporary electrical glitches.

When B1660 is stored, the module also captures freeze frame data: a snapshot of engine rpm, load, temperature, and vehicle speed at the exact moment the fault was detected. This information is invaluable during diagnosis because it tells you what conditions the vehicle was under when the problem occurred, guiding you toward the most likely source of the open circuit.

Symptoms of B1660

The driver seat up adjustment function fails to operate or works intermittently
Other body electrical functions (windows, locks, lighting) may also be affected if the fault shares a common circuit or ground
No effect on engine performance, transmission operation, or braking systems
Dashboard warning light illuminated (body/module indicator)
Seat may be stuck in a lowered position, reducing driver visibility and comfort
In some cases, adjacent seat functions (forward/back, recline) operate normally while the up circuit remains non-functional

Common Causes

Internally failed seat adjustment motor or actuator (most frequent culprit)
Broken or chafed wire within the seat harness, especially near seat tracks where flexing occurs
Blown fuse or failed relay that supplies power to the seat adjustment circuit
Connector pins that are corroded, bent, or completely backed out of the housing
Faulty driver seat switch with internally open contacts
Body control module internal failure affecting the seat circuit output
Wiring damaged by water intrusion in the floor pan or door sill areas

How to Diagnose B1660

Connect an OBD2 scanner and confirm B1660 is present, then record all freeze frame data—this tells you the vehicle speed, engine load, and temperature when the fault occurred.
Pull any additional stored codes. B1660 frequently appears alongside other body system codes that can point toward a shared power source, ground, or the BCM itself as the root cause.
Visually inspect the seat wiring harness and all connectors from the seat switch to the adjustment motor. Look for broken insulation, crushed wires near seat mounting bolts, and any signs of corrosion on connector pins.
Perform a continuity test on the seat up circuit with the harness disconnected at both ends. Wiggle the wiring along the seat track while monitoring—the meter will show an intermittent open if the wire is fractured internally.
Test the seat switch for continuity in both positions. An ohmmeter should show near-zero resistance when the switch is pressed and infinite resistance when released; any reading outside this indicates switch failure.
Verify battery voltage at the motor connector while someone presses the switch—if voltage is present but the motor does not run, the motor itself is failed.
After repairs, clear B1660 and complete a full drive cycle matching the freeze frame conditions to ensure the code does not return.

Repair Options and Costs

BCM repair or replacement: $300–$900
This is the most expensive scenario and should only be pursued after wiring and switches have been ruled out. Some shops offer BCM repair (reflashing or internal component replacement) at the lower end of the range.

Wiring harness repair or connector replacement: $80–$250
Often the actual problem, especially in vehicles with high mileage or a history of water intrusion. Splicing damaged wires and replacing corroded connectors typically costs on the lower end; full harness replacement runs higher.

Seat adjustment switch or motor replacement: $120–$450
Aftermarket switches range from $30–$80 plus labor; OEM units cost more. A replacement motor (often sold as a complete actuator assembly) typically runs $100–$250 for parts plus installation labor.

Total repair cost for B1660 typically falls between $80 and $900, depending on which component is at fault. Starting with visual inspection and switch testing before replacing expensive modules is the practical approach—an accurate diagnosis upfront saves hundreds.

Can You Drive With B1660?

B1660 is classified as a short severity code. The seat adjustment fault does not affect engine operation, steering, or braking, so the vehicle remains safe to drive in most conditions. The primary inconvenience is a non-functional seat height adjustment and the illuminated dashboard light. However, if the seat is stuck in an awkward position that obstructs your view or prevents proper distance from the steering wheel, address the issue before long trips. Central locking and exterior lighting faults paired with this code warrant sooner attention for security and visibility reasons.