The B1732 diagnostic trouble code (DTC) indicates a problem within the driver's seat adjustment system, specifically a short to ground in the circuit controlling the rear-down movement of the seat. This malfunction can prevent the driver from properly adjusting their seat, impacting comfort and potentially safety. Addressing this issue promptly is crucial to restore full seat functionality and prevent further electrical damage.
B1732 Diagnostic Trouble Code: Comprehensive Overview
| Category | Description | Possible Causes |
|---|---|---|
| Definition | B1732: Seat Driver Rear Down Switch Circuit Short to Ground | Short circuit in the rear down switch circuit: This is the most direct cause. A wire is making unintended contact with the vehicle's chassis or another ground point. |
| Faulty rear down seat switch: The switch itself may be internally shorted, providing a continuous ground even when not activated. | ||
| Damaged wiring harness: The wiring harness leading to the seat and switch can be damaged due to wear, chafing, or pinching, leading to a short to ground. Common locations are under the seat where movement can cause rubbing. | ||
| Corroded or loose connectors: Corrosion or loose connections within the seat motor or switch connector can create a path to ground. | ||
| Faulty seat control module (SCM): Although less likely, a malfunctioning SCM could incorrectly interpret signals or introduce a short internally. | ||
| Symptoms | Seat will not move down in the rear. | The rear portion of the driver's seat will be unresponsive when attempting to lower it. |
| Seat moves down in the rear without input. | The seat might move down without the driver pressing the switch, indicating a constant ground path. | |
| Blown fuses. | Repeatedly blown fuses in the seat control circuit are a strong indicator of a short to ground. | |
| Other seat functions malfunctioning. | Depending on the vehicle's wiring architecture, other seat adjustments may be affected. | |
| Battery drain (in severe cases). | A constant short to ground can drain the vehicle's battery over time, especially if the vehicle is left parked for extended periods. | |
| Diagnostic Steps | Visual inspection of wiring and connectors. | Check for obvious signs of damage, corrosion, or loose connections under the seat. |
| Testing the rear down switch. | Use a multimeter to check the switch's continuity and resistance. Confirm that the switch is not internally shorted. | |
| Testing the wiring harness for shorts. | Use a multimeter to check for continuity between the rear down switch circuit wire and ground. This confirms the short. | |
| Isolating the short by disconnecting components. | Disconnect the switch, then the motor, and then the SCM (if applicable) one at a time to see if the short disappears. This helps pinpoint the faulty component. | |
| Checking for voltage at the switch. | Verify that the switch is receiving the correct voltage when activated. | |
| Consulting wiring diagrams. | Use the vehicle's wiring diagram to trace the circuit and identify potential problem areas. | |
| Repair Procedures | Repairing or replacing damaged wiring. | Repair any breaks or chafing in the wiring harness, ensuring proper insulation. |
| Replacing the rear down seat switch. | If the switch is faulty, replace it with a new, OEM-quality switch. | |
| Cleaning or replacing corroded connectors. | Clean or replace any corroded connectors to ensure a solid electrical connection. | |
| Replacing the seat control module (SCM). | If the SCM is faulty, replace it with a new or refurbished unit. This is usually a last resort. | |
| Replacing blown fuses. | Replace any blown fuses with the correct amperage rating. If the fuse blows again immediately, the short is still present. | |
| Tools Required | Multimeter | For testing continuity, voltage, and resistance. |
| Wiring diagrams | To understand the circuit layout. | |
| Wire strippers and crimpers | For repairing or replacing wiring. | |
| Electrical tape or heat shrink tubing | For insulating repaired wiring. | |
| Socket set and wrenches | For removing seat components. | |
| Scan tool (optional) | For reading and clearing DTCs. | |
| Related DTCs | B1731: Seat Driver Rear Up Switch Circuit Short to Ground | Similar to B1732, but related to the rear-up switch circuit. |
| B1733: Seat Driver Rear Down Switch Circuit Open | Indicates an open circuit in the rear-down switch circuit. | |
| B1727-B1730: Related to other seat adjustment switches. | Indicates similar issues with other seat adjustment circuits. | |
| Severity | Medium | While not immediately impacting vehicle operation, it can affect driver comfort and safety. A persistent short can also lead to battery drain. |
| Cost to Repair | Variable | Depends on the cause. Replacing a switch is relatively inexpensive, while repairing a complex wiring harness or replacing the SCM can be more costly. Labor costs will also vary. |
Detailed Explanations
Definition: The B1732 code signifies that the vehicle's computer has detected an unwanted electrical connection to ground within the circuit that controls the rear-down movement of the driver's seat. This means that the electrical signal intended to activate the seat motor is being diverted to ground before reaching its destination.
Short circuit in the rear down switch circuit: This is the core issue. A wire carrying power or signal for the rear down seat function is making unintended contact with the vehicle's metal chassis or another grounded component. This provides an easy path for electricity to flow to ground, bypassing the intended circuit.
Faulty rear down seat switch: The physical switch that the driver uses to control the seat might be internally damaged. An internal short within the switch can cause it to constantly send a ground signal, even when the button is not pressed.
Damaged wiring harness: The wires that connect the switch to the seat motor and the seat control module are bundled together in a harness. This harness can be damaged by rubbing against the seat frame, getting pinched, or being exposed to extreme temperatures. This damage can expose the wires and cause them to short to ground.
Corroded or loose connectors: Electrical connectors are used to join different parts of the seat adjustment system. Over time, these connectors can corrode due to moisture or become loose due to vibration. Corrosion or looseness can create a path to ground, triggering the B1732 code.
Faulty seat control module (SCM): The SCM is the computer that controls the seat's various functions. Although less common, the SCM itself could be malfunctioning and causing the short to ground. This is often the last suspect after other components have been ruled out.
Seat will not move down in the rear: The most obvious symptom is the inability to lower the rear portion of the driver's seat. The motor simply will not respond when the driver presses the rear-down switch.
Seat moves down in the rear without input: In some cases, the seat might move down on its own without the driver activating the switch. This happens when the short to ground is constant, creating a perpetual signal to lower the seat.
Blown fuses: A short to ground draws excessive current, which can cause the fuse protecting the seat circuit to blow. If the fuse repeatedly blows after being replaced, it's a strong indication of a short circuit.
Other seat functions malfunctioning: Depending on the vehicle's electrical system design, a short in one seat circuit can sometimes affect other seat functions. This happens when multiple seat functions share a common ground or power source.
Battery drain (in severe cases): A severe and continuous short to ground can drain the vehicle's battery, especially if the vehicle is left parked for a long period.
Visual inspection of wiring and connectors: This is the first step in diagnosing the problem. Carefully inspect the wiring harness under the seat for any signs of damage, such as cuts, abrasions, or exposed wires. Also, check the connectors for corrosion or looseness.
Testing the rear down switch: Use a multimeter to test the switch's continuity. When the switch is not activated, there should be no continuity. When the switch is activated, there should be continuity. If the switch shows continuity even when not activated, it's likely shorted internally.
Testing the wiring harness for shorts: A multimeter can be used to check for continuity between the wire that carries the signal from the rear down switch and the vehicle's chassis ground. If there's continuity, it confirms a short to ground.
Isolating the short by disconnecting components: This involves systematically disconnecting components in the circuit, starting with the switch and moving towards the seat motor and the SCM. After disconnecting each component, recheck for the short to ground. When the short disappears, the last disconnected component is likely the source of the problem.
Checking for voltage at the switch: Use a multimeter to verify that the switch is receiving the correct voltage when activated. A lack of voltage can indicate a problem upstream in the circuit.
Consulting wiring diagrams: A wiring diagram is an essential tool for understanding the seat adjustment system's circuit layout. It helps trace the wiring and identify potential problem areas.
Repairing or replacing damaged wiring: If damaged wiring is found, it needs to be repaired or replaced. Use proper wiring techniques, such as soldering and heat-shrinking, to ensure a reliable and durable repair.
Replacing the rear down seat switch: If the switch is faulty, it needs to be replaced with a new, OEM-quality switch.
Cleaning or replacing corroded connectors: Corroded connectors should be cleaned with a wire brush or contact cleaner. Severely corroded connectors should be replaced.
Replacing the seat control module (SCM): Replacing the SCM should be a last resort, as it's often the most expensive repair. Before replacing the SCM, ensure that all other potential causes have been ruled out.
Replacing blown fuses: Replace any blown fuses with the correct amperage rating. If the fuse immediately blows again, the short to ground is still present and needs to be addressed.
Multimeter: A multimeter is a versatile tool used to measure voltage, current, and resistance. It's essential for diagnosing electrical problems.
Wiring diagrams: Wiring diagrams are schematics that show the layout of the vehicle's electrical circuits. They are invaluable for tracing wires and identifying components.
Wire strippers and crimpers: These tools are used to strip insulation from wires and crimp connectors onto them.
Electrical tape or heat shrink tubing: These materials are used to insulate repaired wiring and protect it from moisture and corrosion.
Socket set and wrenches: These tools are used to remove seat components, such as the switch, motor, and SCM.
Scan tool (optional): A scan tool can be used to read and clear DTCs. It can also provide additional information about the seat adjustment system.
B1731: Seat Driver Rear Up Switch Circuit Short to Ground: This code indicates a similar problem but related to the rear-up movement of the seat. The troubleshooting steps are similar.
B1733: Seat Driver Rear Down Switch Circuit Open: This code indicates an open circuit, meaning a break in the wiring, rather than a short to ground.
B1727-B1730: Related to other seat adjustment switches: These codes indicate similar problems with other seat adjustment circuits, such as the front-up/down or forward/backward adjustments.
Severity: The severity of the B1732 code is considered medium. While it doesn't typically affect the vehicle's ability to run, it can impact driver comfort and safety. A persistent short can also lead to battery drain.
Cost to Repair: The cost to repair the B1732 code can vary depending on the cause. Replacing a switch is relatively inexpensive, while repairing a complex wiring harness or replacing the SCM can be more costly. Labor costs will also vary.
Frequently Asked Questions
What does the B1732 code mean? The B1732 code indicates a short to ground in the driver's seat rear-down switch circuit, meaning the circuit is unintentionally connected to the vehicle's ground.
What are the symptoms of a B1732 code? Common symptoms include the rear portion of the driver's seat not moving down, the seat moving down without input, and blown fuses in the seat circuit.
Can I fix the B1732 code myself? Depending on your mechanical skills, you may be able to diagnose and repair the problem yourself. However, electrical troubleshooting requires a multimeter and knowledge of wiring diagrams.
How do I find the short to ground? Use a multimeter to check for continuity between the rear-down switch circuit wire and ground. Disconnect components one by one to isolate the short.
Is it safe to drive with the B1732 code? While generally safe to drive, the inability to adjust the seat properly can affect comfort and potentially safety. A persistent short can also drain the battery.
Conclusion
The B1732 code indicates a short to ground in the driver's seat rear-down switch circuit, which can prevent proper seat adjustment. Thorough diagnosis and repair, including visual inspection, electrical testing, and component isolation, are necessary to resolve the issue and restore full seat functionality. It is recommended to consult a qualified mechanic if you are not comfortable performing electrical troubleshooting.