B1660 — Seat Driver Front Up Circuit Open #

Note: The exact wording of this code may vary depending on the vehicle manufacturer. Below are known label variations for B1660:

• Seat Driver Front Up Circuit Open (Ford, Mazda, Nissan, Toyota, Honda, GM, Hyundai/Kia)
• Driver’s Seat Height Adjustment Circuit Open (Toyota, Lexus)
• Front Power Seat Height Sensor Circuit Open (GM, Cadillac)
• Seat Height Motor Circuit Open (Hyundai, Kia)

Summary of Code B1660 #

The B1660 diagnostic trouble code (DTC) signals an electrical open condition in the circuit responsible for raising or adjusting the front height of the driver’s seat. This code is set by the Body Control Module (BCM)—the computer managing many interior and comfort features—when it detects that the seat height adjuster motor (or its associated wiring) is no longer forming a complete circuit. In simple terms, the BCM is expecting a flow of electricity to a particular part of the seat adjustment system, but the circuit is “open,” similar to flipping a light switch off. This can be due to a wiring break, a failed switch, or a faulty motor. The code’s presence means that the seat’s up/down adjustment may not function as intended, impacting comfort and sometimes safety for the driver.

Common Symptoms for B1660 #

When the B1660 code is active, drivers and technicians may notice several telltale signs. The most prominent issue is a non-functional driver’s seat height adjustment, but there can be additional warnings or inconveniences. Below are the typical symptoms:

• Driver’s seat front up/down adjustment does not work
• Power seat motor makes no sound or movement when the up/down switch is pressed
• No response from seat height control switch
• Potential seat adjustment warning light illuminated (on some vehicles)
• Seat moves in other directions (back/forth, recline) but not up/down

Likely Causes of B1660 (in order of frequency) #

This code can result from a handful of electrical or mechanical issues. Based on frequency and real-world diagnostics, here’s what typically causes B1660:

1. Broken or damaged wiring between the BCM and the seat height motor
2. Faulty seat height adjustment motor (also called the “front up motor”)
3. Defective seat adjustment switch (the switch you press to move the seat up or down)
4. Disconnected or corroded connector at the seat motor or switch
5. Blown fuse in the seat adjustment circuit
6. Internal BCM fault (rare, but possible)

Step-by-Step Diagnostic Process for B1660 #

Diagnosing code B1660 efficiently requires a systematic approach, starting with the simplest possibilities and moving toward more complex issues. Here’s how a professional technician would tackle it:

• Verify the code: Use a scan tool to confirm B1660 is current and not a stored or history code. Clear the code and see if it returns after using the seat adjustment.
• Check seat function: Manually test the driver’s seat up/down adjustment and note if other seat movements function normally.
• Inspect fuses: Locate and inspect all fuses related to power seat operation; replace if blown.
• Perform a visual inspection: Examine wiring and connectors under the seat for damage, pinching, corrosion, or disconnection.
• Test switch operation: Use a multimeter or scan tool to check if the up/down switch is sending a signal when pressed.
• Test motor operation: Apply direct battery voltage to the seat height motor to see if it runs. If it doesn’t, replace the motor.
• Check continuity: Using a wiring diagram, test for continuity between the BCM, switch, and motor. Repair any open circuits.
• Scan BCM for related codes: Look for other codes that may indicate a broader BCM or communication issue.

Possible Repairs for B1660 #

Once the cause is pinpointed, the appropriate repair can be carried out. Here’s what technicians typically do, based on the underlying issue:

• Repair or replace damaged wiring between the seat and BCM
• Replace the seat height adjustment motor if it fails direct power testing
• Replace the seat adjustment switch if it’s not sending the proper signal
• Reconnect or replace corroded connectors under the seat
• Replace blown fuses and investigate why the fuse blew
• In rare cases, replace the BCM if all other components check out and no wiring faults are found

Is It Safe to Drive with Code B1660? #

Yes, you can generally drive with code B1660 present, but with limitations. This code does not affect the core safety or drivability of your vehicle. However, it does mean the driver’s seat up/down adjustment feature will not work, which can be uncomfortable or even unsafe if you cannot reach the pedals or see the road properly due to improper seat positioning. If you share your vehicle with other drivers of different heights, it’s best to address the issue promptly.

Vehicles Most Commonly Affected by B1660 #

This code appears most frequently in vehicles equipped with power-adjustable seats, particularly those from the following manufacturers:

• Ford (F-150, Fusion, Explorer, Expedition, Taurus)
• Mazda (Mazda3, Mazda6, CX-5, CX-9)
• Toyota (Camry, Avalon, Highlander, RAV4, Lexus ES/GS series)
• Nissan (Altima, Maxima, Murano, Pathfinder)
• GM (Chevrolet Malibu, Impala, Cadillac CTS, Buick Enclave)
• Hyundai/Kia (Sonata, Santa Fe, Tucson, Optima, Sorento)

Common Mistakes & Best Practices for B1660 #

Even experienced mechanics can make errors when troubleshooting this code. Here’s what to watch out for—and how to avoid unnecessary repairs:

• Replacing the seat motor or switch without checking the wiring first
• Overlooking a simple blown fuse or loose connector
• Not testing seat functions after repairs to confirm the fix
• Ignoring other related seat or BCM fault codes that could point to a broader issue
• Failing to check for pinched or damaged wires under the seat, especially after seat removal or interior work

Quick FAQ for B1660 #

Q: Can I adjust my seat in other directions if I have code B1660?
A: Yes, typically only the up/down function is affected. Forward/backward and recline adjustments usually work, but always verify all seat operations.

Q: Will clearing the code with a scan tool fix the problem?
A: No, clearing the code will remove the warning temporarily, but if the underlying electrical issue is not fixed, the code will return as soon as you attempt to use the seat height adjustment again.

Q: Is this an expensive repair?
A: Costs vary depending on the root cause. Simple wiring or connector repairs are inexpensive, while replacing motors or switches can be more costly, especially if OEM (Original Equipment Manufacturer) parts are required.