The B1660 diagnostic trouble code (DTC) signals an issue within the driver's seat's vertical adjustment system, specifically an open circuit in the "up" direction motor control. This means the seat may not move upwards, potentially affecting driving comfort and visibility. Addressing this problem promptly is crucial for both safety and convenience.
This article delves into the specifics of the B1660 code, covering its potential causes, diagnostic procedures, and possible solutions. Understanding this code can empower you to troubleshoot the issue yourself or communicate effectively with a mechanic.
| Component | Description | Potential Causes |
|---|---|---|
| Seat Adjustment Motor (Up) | The electric motor responsible for raising the driver's seat. | Blown fuse for the seat motor circuit. Open circuit in the wiring harness between the seat motor and the seat control module (SCM). Corroded or loose electrical connectors. Faulty seat adjustment switch (specifically the "up" function). Damaged or internally shorted seat adjustment motor. Faulty Seat Control Module (SCM). Wiring harness damage due to abrasion or pinching. Incorrect voltage to the seat motor circuit. |
| Wiring Harness | The collection of wires that connect the seat adjustment motor, switch, and Seat Control Module (SCM). | Open circuit due to broken or cut wires. Short circuit to ground or power. Corroded or damaged connectors. Loose connections. * Wire chafing against metal components. |
| Seat Control Module (SCM) | The electronic module that controls the seat adjustment functions. | Internal SCM failure. Corrupted software within the SCM. Damaged SCM connector pins. Loss of power or ground to the SCM. |
| Seat Adjustment Switch | The switch used to control the seat's up/down movement. | Faulty switch contacts preventing proper signal transmission. Internal switch damage. Loose or corroded switch connector. Mechanical binding within the switch mechanism. |
| Fuses and Relays | Protective components in the electrical circuit. | Blown fuse protecting the seat motor circuit. Malfunctioning relay controlling the seat motor power. * Corroded fuse or relay contacts. |
| Ground Connection | The electrical connection providing a return path for the circuit. | Loose or corroded ground connection. Broken ground wire. * Insufficient ground connection resulting in voltage drop. |
| Power Supply to SCM | The power source for the Seat Control Module. | Low voltage to the SCM. Intermittent power supply to the SCM. * Wiring issues affecting the SCM power supply. |
Detailed Explanations
Seat Adjustment Motor (Up): This motor is responsible for physically raising the driver's seat. It receives power from the Seat Control Module (SCM) when the "up" switch is activated. A failure within the motor itself, such as worn brushes or a shorted winding, can prevent it from functioning and trigger the B1660 code.
Wiring Harness: The wiring harness serves as the communication pathway between the seat adjustment motor, the seat adjustment switch, and the Seat Control Module (SCM). Damage to the wiring, such as cuts, breaks, or corrosion, can disrupt the electrical circuit and cause an open circuit, leading to the B1660 code. Thorough inspection of the wiring harness is crucial for identifying any potential issues.
Seat Control Module (SCM): The SCM is the brain of the seat adjustment system. It receives signals from the seat adjustment switch and controls the power to the seat adjustment motors. If the SCM malfunctions, it may not be able to properly control the "up" motor, resulting in the B1660 code. Replacing the SCM is typically a last resort after other potential causes have been ruled out.
Seat Adjustment Switch: This switch allows the driver to control the seat's vertical movement. When the "up" position is selected, the switch sends a signal to the SCM, which then activates the "up" motor. A faulty switch can prevent the signal from reaching the SCM, leading to the B1660 code.
Fuses and Relays: Fuses protect the electrical circuits from overcurrent, while relays act as electrically controlled switches. A blown fuse or a malfunctioning relay in the seat motor circuit can interrupt the power supply to the motor, causing the B1660 code. Checking and replacing any blown fuses or faulty relays is a simple first step in troubleshooting.
Ground Connection: A solid ground connection is essential for the proper functioning of any electrical circuit. A loose or corroded ground connection can create resistance in the circuit, leading to voltage drops and potentially causing the B1660 code. Ensure the ground connection for the seat adjustment system is clean, tight, and free of corrosion.
Power Supply to SCM: The Seat Control Module requires a stable and adequate power supply to function correctly. If the voltage to the SCM is low or intermittent, it may not be able to properly control the seat adjustment motors, leading to the B1660 code.
Troubleshooting Steps
- Check the Fuse: Locate the fuse for the seat adjustment system (refer to your vehicle's owner's manual). Inspect the fuse to see if it is blown. If so, replace it with a fuse of the same amperage rating.
- Inspect the Wiring Harness: Carefully examine the wiring harness that connects the seat motor, switch, and SCM. Look for any signs of damage, such as cuts, breaks, or corrosion. Pay close attention to areas where the wiring might be pinched or rubbing against metal components.
- Check Connectors: Inspect all electrical connectors in the seat adjustment system. Make sure they are securely connected and free of corrosion. Clean any corroded connectors with electrical contact cleaner.
- Test the Seat Adjustment Switch: Use a multimeter to test the seat adjustment switch for continuity. Verify that the switch is sending a signal to the SCM when the "up" position is selected.
- Test the Seat Adjustment Motor: Use a multimeter to test the seat adjustment motor for continuity. You can also try applying direct power to the motor to see if it runs. Caution: Disconnect the motor from the vehicle's wiring harness before applying direct power.
- Check the Ground Connection: Locate the ground connection for the seat adjustment system. Make sure it is clean, tight, and free of corrosion.
- Scan for Other DTCs: Use an OBD-II scanner to check for any other DTCs that may be related to the B1660 code. Other codes can provide clues about the underlying cause of the problem.
- Inspect the Seat Control Module (SCM): Visually inspect the SCM for any signs of damage, such as burnt components or corroded connector pins. If you suspect the SCM is faulty, you may need to have it tested by a qualified technician.
- Check Power Supply to SCM: Using a multimeter, verify that the SCM is receiving the correct voltage and ground. Refer to your vehicle's service manual for the correct voltage specifications.
Frequently Asked Questions
- What does the B1660 code mean? It indicates an open circuit in the driver's seat "up" adjustment motor control circuit.
- Can I fix this myself? Potentially, if you have basic electrical knowledge and tools. Start with the simple checks like fuses and wiring.
- How much will it cost to fix? The cost varies depending on the cause. A blown fuse is inexpensive, while replacing the SCM can be costly.
- Is it safe to drive with this code? It's generally safe, but the seat may not adjust properly, affecting driving comfort and visibility.
- What tools do I need to diagnose this? You'll need a multimeter, basic hand tools, and possibly an OBD-II scanner.
- Where is the seat control module located? Its location varies by vehicle make and model. Consult your vehicle's service manual.
Conclusion
The B1660 DTC signifies an open circuit in the driver's seat's upward adjustment mechanism. By systematically checking components like fuses, wiring, the adjustment switch, and the motor itself, you can often identify and resolve the issue. If the problem persists, seeking professional assistance from a qualified mechanic is recommended to ensure proper diagnosis and repair.