B1708 — Seat Driver Recline Rearward Switch Circuit Short To Ground #

Note: The code label may vary depending on the vehicle manufacturer (OEM). Always refer to your vehicle’s official service documentation for precise terminology.

• Seat Recline Rearward Switch Circuit Shorted to Ground (Ford, Lincoln)
• Driver’s Seat Recline Switch Rearward Circuit Low (Toyota, Lexus)
• Seat Back Adjust Rearward Switch Short to Ground (GM, Chevrolet, Buick)

Summary of B1708 #

The B1708 diagnostic trouble code (DTC) indicates that the driver’s seat recline rearward switch circuit is experiencing a short to ground. In simple terms, this electrical fault means that the circuit responsible for moving the seatback rearward is unintentionally connected to the vehicle’s ground, causing abnormal function or inoperability. This code is set by the Body Control Module (BCM) or Seat Control Module (SCM) when it detects a voltage lower than expected in the switch circuit. While not a critical safety code, it can impact driver comfort and seat adjustability, especially in vehicles with memory or powered seat features. Addressing this code promptly helps ensure proper seat operation and avoids further electrical issues.

Common Symptoms for Code B1708 #

When a B1708 code is present, drivers may notice subtle to obvious changes in seat operation. Some symptoms are immediate, while others develop as the fault persists. Watch for any of the following:

• Driver seat will not recline rearward when using the switch
• Intermittent or no response from the seatback adjustment switch
• Seat memory functions fail to adjust seatback angle properly
• Warning light or seat adjustment error message on the dashboard (on some models)
• Clicking or relay noises when attempting to move the seat

Most Likely Causes for B1708 #

A “short to ground” in the seat recline switch circuit can stem from several sources. The frequency of each cause can vary by vehicle age, use, and environment. Here’s what technicians often find, listed from most to least common:

1. Damaged or pinched seat wiring harness under the seat track
2. Faulty recline rearward switch (mechanical or internal electrical fault)
3. Corrosion or water intrusion at switch or connector terminals
4. Seat control module (SCM) malfunction
5. Poor ground connections or broken ground wires nearby

Step-by-Step Diagnostic for B1708 #

Diagnosing a B1708 code requires patience and attention to detail. The following steps will help you pinpoint the issue effectively:

1. Scan the vehicle with a professional OBD-II/EOBD tool to confirm code presence and check for related seat or BCM codes.
2. Visually inspect the seat wiring harness for signs of damage, pinching, chafing, or exposed wires, especially where the harness flexes with seat movement.
3. Check the seat recline switch for physical damage, sticking, or signs of moisture/corrosion at the switch or its connector.
4. Test circuit continuity using a multimeter: Disconnect the seat switch and check for continuity to ground on the rearward switch wire. Any unexpected continuity indicates a short.
5. Inspect the seat control module and ground points under the seat for loose connectors, corrosion, or water damage.
6. Refer to OEM wiring diagrams to trace and isolate the affected circuit if the problem is not visually apparent.

Possible Repairs for B1708 #

Once the fault is identified, repairs should focus on restoring the seat switch circuit’s integrity. The following solutions correspond to the most common causes:

• Repair or replace damaged wiring under the seat; use high-quality automotive wire and connectors.
• Replace the seat recline rearward switch if it tests faulty or shows physical/internal damage.
• Clean and protect switch/connector terminals from corrosion; apply dielectric grease before reassembly.
• Replace or reprogram the seat control module if diagnosed as faulty (OEM procedure recommended).
• Restore or repair ground connections as needed, ensuring a solid and corrosion-free ground.

Is It Safe to Drive with Code B1708? #

Yes, but with limitations: Driving with a B1708 code does not pose an immediate safety risk since it does not affect primary vehicle operation or critical safety systems. However, you may not be able to adjust the driver seatback, which can impact driving comfort, especially on long journeys or for multiple drivers. Prompt repair is recommended to restore seat functionality and prevent further electrical faults.

Vehicles Most Affected by B1708 #

While the B1708 code is most often associated with vehicles equipped with electrically adjustable driver seats, it can appear in a wide range of models. The following vehicles are commonly reported with this DTC:

• Ford F-Series, Explorer, Taurus
• Lincoln MKZ, Navigator
• Chevrolet Silverado, Tahoe
• Buick Enclave
• Toyota Camry, Avalon
• Lexus ES, RX
• Some Nissan and Infiniti models with power seats

Common Mistakes & Best Practices for B1708 #

Technicians and DIYers sometimes fall into common traps when addressing a B1708 code. To ensure efficient and lasting repairs, keep these points in mind:

• Don’t replace the seat switch or module without first verifying wiring integrity. Many faults are due to pinched or damaged wires under the seat.
• Avoid forcing seat movement while the fault is present, as this can cause further damage to wiring or seat motors.
• Always disconnect the vehicle battery before working on seat wiring to prevent accidental airbag deployment (especially in seats with side airbags).
• Use OEM wiring diagrams and connector pinouts to ensure proper diagnosis and repair.
• Check for water leaks or moisture under the seat, especially after heavy rain or spills.

B1708 Quick FAQ #

Still have questions? Here are answers to what drivers and technicians ask most often about B1708:

• Q: Will clearing the code with a scan tool fix the problem?
  A: No. Clearing the code without addressing the underlying short will only result in the code returning as soon as the seat switch circuit is tested again.
• Q: Can a blown fuse cause a B1708 code?
  A: Not directly. B1708 specifically refers to a short to ground in the switch circuit, not an open circuit. However, repeated shorts can eventually blow seat circuit fuses.
• Q: Is it safe to attempt wiring repairs myself?
  A: If you have basic electrical skills and follow safety guidelines (battery disconnected, verify airbag locations), minor wire repairs are manageable. For complex or module-related faults, professional service is recommended.