B1655 — Seat Driver Rear Up Circuit Failure #

Note: The exact wording for this Diagnostic Trouble Code (DTC) may vary depending on the vehicle manufacturer. Always refer to your OEM (Original Equipment Manufacturer) service documentation for precise terminology.

• Seat Driver Rear Up Circuit Malfunction (Ford, Mazda)
• Seat Height Adjustment Rear Up Circuit Fault (Toyota, Lexus)
• Driver Seat Rear Height Actuator Circuit Error (GM, Chevrolet)

Summary of DTC B1655 #

The B1655 code indicates a problem in the electrical circuit controlling the rear upward movement of the driver’s seat. This circuit typically includes the seat adjustment switch, wiring harness, connectors, and the seat motor actuator that raises the rear portion of the seat cushion. When the Body Control Module (BCM) or Seat Control Module (SCM) detects an open, short, or other irregularity in this circuit, it triggers B1655 and may disable seat adjustment functions for safety. While this issue does not usually affect drivability, it can impact comfort and ergonomics, especially for drivers with specific seat positioning needs. Prompt diagnosis ensures continued comfort and prevents further electrical complications.

Common Symptoms for DTC B1655 #

When B1655 is active, you may notice specific changes in how your power seat behaves. Symptoms are typically limited to seat adjustment, but can sometimes overlap with other electronic seat features. Here are the most frequent warning signs:

• Driver’s seat rear height fails to move upward when using the adjustment switch
• No response or unusual noises from the seat motor when attempting rear-up adjustment
• Intermittent seat movement or seat stops partway through adjustment
• Illuminated seat adjustment warning light (if equipped)
• Other seat adjustment directions may function normally

Probable Causes for B1655 (from Most to Least Common) #

B1655 is generally triggered by disruptions in the seat’s rear-up circuit. These disruptions can arise from a variety of sources, ranging from simple wiring issues to failed components. Here’s a prioritized list based on how frequently each cause is observed:

1. Faulty seat adjustment switch (worn or broken internal contacts)
2. Damaged wiring harness (chafed, pinched, or corroded wires in the seat area)
3. Loose or corroded electrical connectors between switch, seat motor, and control module
4. Malfunctioning rear-up seat motor/actuator (internal failure or burned-out motor)
5. Seat Control Module (SCM) or Body Control Module (BCM) fault (rare, but possible)
6. Blown fuse related to seat adjustment circuit

Step-by-Step Diagnosis for B1655 #

Diagnosing B1655 requires patience and attention to electrical detail. Begin with the simplest possibilities and work progressively toward more complex causes. Always disconnect the battery before working with seat wiring to avoid accidental airbag deployment.

1. Confirm the code with a scan tool and check for related seat adjustment DTCs.
2. Inspect the seat adjustment switch for physical damage, sticking, or lack of tactile feedback.
3. Check all visible wiring from the seat switch to the seat motor for pinching, chafing, or corrosion—especially under the seat where movement is frequent.
4. Test connectors for secure fit and absence of corrosion or bent pins.
5. Using a multimeter, verify continuity in the rear-up circuit between the switch and the seat motor.
6. Apply direct battery voltage (with proper precautions) to the seat rear-up motor to see if it operates independently.
7. If all hardware checks out, inspect and test the Seat Control Module or Body Control Module for faults (consult OEM service data for procedures).

Possible Repairs for B1655 #

Once the root cause is identified, repair should address the faulty component or connection. It’s essential to retest the system after each step to confirm the issue is resolved.

• Replace the seat adjustment switch if internal contacts are worn or broken
• Repair or replace damaged wiring harnesses beneath or around the seat
• Clean, tighten, or replace electrical connectors as needed
• Replace the rear-up seat motor/actuator if it fails direct power testing
• Replace or reprogram the Seat Control Module or Body Control Module (rare; follow OEM guidance)
• Replace any blown fuses and investigate root cause to prevent recurrence

Is It Safe to Drive with Code B1655? #

Yes, you can continue driving with code B1655 in most cases. This fault does not affect engine, transmission, or safety systems. However, if you rely on specific seat height adjustments for comfortable or safe driving, and the seat remains in an awkward or unsafe position, you should have it repaired promptly. Never attempt seat repairs while driving or with the ignition on, as this may trigger airbag-related issues.

Vehicles Most Commonly Affected by B1655 #

While B1655 is a generic OBD-II code, it most often appears on vehicles with electric seat height adjustment features—particularly mid-range and luxury models from the late 1990s onward. Some manufacturers and platforms see this code more frequently due to seat design or wiring routing.

• Ford (Fusion, Escape, Explorer, F-150 series)
• Mazda (CX-5, Mazda6, Mazda3 with power seats)
• Toyota (Camry, Avalon, Highlander, Lexus ES/GS/LS)
• General Motors (Chevrolet Malibu, Impala, Cadillac, GMC trucks with powered seats)
• Hyundai and Kia (Sonata, Santa Fe, Sorento)

Common Mistakes & Best Practices for B1655 #

Diagnosing electrical seat issues can be tricky. Avoid common pitfalls and follow these best practices to ensure an accurate and safe repair.

• Don’t assume the seat motor is faulty without testing power/ground at the connector.
• Do not overlook simple wiring issues—damaged wires under the seat are a leading cause.
• Never work on seat wiring or connectors with the ignition on; disconnect the battery first to avoid airbag deployment.
• Always retest the system after repairs and clear the code with a scan tool.
• Consult OEM wiring diagrams to confirm circuit routing and connector locations.

Quick FAQ for Code B1655 #

Here are fast answers to some of the most common questions about B1655:

• Q: Will my seat memory function still work if B1655 is present?
  A: Other seat memory positions may still operate unless they require the rear-up circuit; some systems disable memory features for safety if a fault is detected.
• Q: Can a blown fuse alone trigger B1655?
  A: Yes, a blown fuse in the seat circuit can cause this code, but it’s important to find and fix the root cause of the fuse failure.
• Q: Is it expensive to fix B1655?
  A: Repair costs vary. Simple wiring or switch issues are typically inexpensive; seat motor or module replacements can be pricier, especially on luxury models.