Introduction
The B1987 Diagnostic Trouble Code (DTC) indicates a malfunction within the pedal position adjustment system, specifically related to the motor responsible for moving the pedals forward or rearward. This code signifies that the vehicle's computer has detected a stall condition within this motor, meaning it's either not moving when commanded or is drawing excessive current while attempting to move, indicating a potential obstruction or internal failure. Addressing this issue promptly is crucial for maintaining driver comfort and safety, as it directly impacts the ability to achieve an optimal driving position.
Comprehensive Table: B1987 Pedal Forward / Rearward Motor Stalled
| Topic | Description | Potential Causes |
|---|---|---|
| Code Definition | B1987: Pedal Forward / Rearward Motor Stalled - This DTC indicates that the vehicle's computer has detected a stall condition within the motor responsible for adjusting the pedals forward or rearward. The stall can be due to the motor being unable to move, drawing excessive current, or failing to respond to commands. | - Obstructed Pedal Movement: Physical obstruction preventing pedal movement (e.g., object lodged in the mechanism). - Faulty Pedal Position Sensor: Inaccurate readings from the sensor can cause the motor to stall trying to reach an impossible position. - Damaged or Worn Pedal Adjustment Mechanism: Physical damage to the rails, gears, or other components of the pedal adjustment system hindering movement. - Low Battery Voltage: Insufficient voltage supply can prevent the motor from operating correctly or cause it to stall. |
| Symptoms | - Pedal adjustment system is inoperative (pedals do not move forward or rearward). - Pedal may be stuck in a fixed position. - Warning light (e.g., check engine light, pedal adjustment system light) illuminated on the dashboard. - Unusual noises (e.g., grinding, clicking) emanating from the pedal adjustment mechanism during attempted operation. - Intermittent operation of the pedal adjustment system. | - Wiring Issues: Damaged, corroded, or loose wiring connections to the motor or control module. - Faulty Pedal Adjustment Motor: Internal failure of the motor itself (e.g., worn brushes, shorted windings). - Faulty Pedal Adjustment Control Module: Malfunction within the control module responsible for commanding the motor. - Mechanical Binding: A seized or binding component within the pedal assembly. |
| Diagnostic Steps | 1. Visual Inspection: Check for any obvious obstructions, damage to wiring, or loose connections. 2. Voltage Check: Verify proper voltage supply to the pedal adjustment motor. 3. Motor Test: Directly test the motor by applying voltage to see if it operates. 4. Sensor Check: Use a scan tool to monitor the pedal position sensor readings. 5. Control Module Check: Use a scan tool to check for any other related DTCs or communication issues. 6. Mechanical Inspection: Manually inspect the pedal adjustment mechanism for binding or damage. | - Software Glitches: Rare instances where the vehicle's software controlling the pedal adjustment system may have a glitch. - Incorrect Calibration: The system may require recalibration after repairs or component replacement. - Overload Protection: The system may be designed to shut down and stall the motor if it detects excessive resistance or current draw to prevent damage. - Environmental Factors: Extreme temperatures or humidity can affect the performance of the motor and electrical components. |
| Common Tools Required | - Scan tool (capable of reading and clearing DTCs). - Multimeter (for voltage and continuity testing). - Basic hand tools (screwdrivers, wrenches). - Wiring diagram (specific to the vehicle). - Inspection mirror and flashlight. | N/A |
| Potential Solutions | - Remove any obstructions preventing pedal movement. - Repair or replace damaged wiring. - Replace the faulty pedal adjustment motor. - Replace the faulty pedal position sensor. - Replace the faulty pedal adjustment control module. - Repair or replace damaged components of the pedal adjustment mechanism. - Recalibrate the pedal adjustment system (if necessary). | N/A |
| Related DTCs | - B1986: Pedal Forward / Rearward Motor Circuit Malfunction - B1988: Pedal Forward / Rearward Motor Overcurrent - B1989: Pedal Forward / Rearward Motor Position Sensor Circuit Malfunction - B1990: Pedal Position Sensor Calibration Error | N/A |
Detailed Explanations
Code Definition: The B1987 code specifically pinpoints a problem with the pedal adjustment motor. It's crucial to understand that the "stall" refers to the motor's inability to function as intended, which can stem from various underlying issues. Ignoring this code can lead to a permanently fixed pedal position, compromising driver comfort and potentially safety.
Symptoms: The symptoms associated with the B1987 code are fairly straightforward. The most obvious symptom is the inability to adjust the pedals. You might also notice a warning light illuminating on your dashboard, which is a clear indicator of a system malfunction. Unusual noises should also raise suspicion, as they often point to mechanical problems within the adjustment mechanism. Intermittent operation is a common symptom, where the pedals work sometimes but not others, which can make the diagnosis more challenging.
Diagnostic Steps: A systematic approach is key to diagnosing the root cause of the B1987 code. The first step should always be a visual inspection to identify any obvious problems. Next, voltage checks are crucial to ensure the motor is receiving the proper power supply. Testing the motor directly can help determine if it's functioning correctly in isolation. A scan tool is essential for checking the pedal position sensor and the control module. Finally, a manual inspection of the mechanical components is necessary to identify any binding or damage.
Common Tools Required: Having the right tools will make the diagnostic and repair process much smoother. A scan tool is indispensable for reading and clearing DTCs and monitoring sensor data. A multimeter is essential for performing voltage and continuity tests. Basic hand tools like screwdrivers and wrenches are needed for disassembly and reassembly. A wiring diagram specific to your vehicle is crucial for tracing circuits and identifying components. Finally, an inspection mirror and flashlight can help you see into tight spaces and identify hidden damage.
Potential Solutions: The solution to the B1987 code depends on the underlying cause. Removing any obstructions is the simplest fix. Repairing or replacing damaged wiring is often necessary. Replacing a faulty motor, sensor, or control module are common solutions. In some cases, repairing or replacing damaged mechanical components is required. Finally, recalibrating the system may be necessary after certain repairs.
Related DTCs: Understanding related DTCs can provide valuable context and help narrow down the problem. Codes like B1986 (Motor Circuit Malfunction), B1988 (Motor Overcurrent), B1989 (Position Sensor Circuit Malfunction), and B1990 (Position Sensor Calibration Error) can offer clues about the specific nature of the issue and guide your diagnostic efforts.
Obstructed Pedal Movement: This is perhaps the simplest cause to diagnose and resolve. An object, such as a floor mat, a dropped item, or even debris, can physically impede the movement of the pedals. Carefully inspect the area around the pedals and remove any obstructions you find.
Faulty Pedal Position Sensor: The pedal position sensor provides feedback to the control module about the pedal's position. If this sensor is faulty, it can send inaccurate readings, causing the motor to stall as it attempts to reach a position that the system believes is incorrect. Testing the sensor with a scan tool is crucial to identify this issue.
Damaged or Worn Pedal Adjustment Mechanism: The pedal adjustment mechanism consists of rails, gears, and other components that allow the pedals to move smoothly. Over time, these components can become worn or damaged, leading to binding or resistance. A thorough visual inspection is essential to identify any physical damage or excessive wear.
Low Battery Voltage: The pedal adjustment motor requires a certain amount of voltage to operate correctly. If the battery voltage is low, the motor may not have enough power to move the pedals, causing it to stall. Check the battery voltage and charging system to ensure they are functioning properly.
Wiring Issues: Damaged, corroded, or loose wiring connections can interrupt the flow of electricity to the motor, causing it to stall. Carefully inspect the wiring harness and connectors for any signs of damage or corrosion. Repair or replace any damaged wiring as needed.
Faulty Pedal Adjustment Motor: The motor itself can fail due to worn brushes, shorted windings, or other internal problems. If the motor is faulty, it will need to be replaced. You can test the motor directly by applying voltage to it to see if it operates.
Faulty Pedal Adjustment Control Module: The control module is responsible for commanding the motor to move the pedals. If the control module is faulty, it may not send the correct signals to the motor, causing it to stall. A scan tool can be used to check for any DTCs related to the control module.
Mechanical Binding: A seized or binding component within the pedal assembly can prevent the motor from moving the pedals. This can be caused by corrosion, lack of lubrication, or physical damage. Manually inspect the pedal adjustment mechanism for any signs of binding.
Software Glitches: While rare, software glitches can sometimes cause the pedal adjustment system to malfunction. In these cases, a software update or reprogramming may be necessary. Consult with a qualified technician to determine if a software update is available for your vehicle.
Incorrect Calibration: The pedal adjustment system may require recalibration after repairs or component replacement. This ensures that the system knows the correct positions of the pedals. Follow the manufacturer's instructions for recalibrating the system.
Overload Protection: The system may be designed to shut down and stall the motor if it detects excessive resistance or current draw to prevent damage. This is a safety feature that protects the motor and other components.
Environmental Factors: Extreme temperatures or humidity can affect the performance of the motor and electrical components. In very cold weather, the motor may not be able to operate as efficiently. In very humid conditions, corrosion can develop on electrical connections.
Frequently Asked Questions
What does the B1987 code mean? It indicates a stalled motor in the pedal adjustment system, preventing the pedals from moving forward or backward.
Can I fix the B1987 code myself? Potentially, if you have mechanical aptitude and diagnostic tools, starting with visual inspections and basic tests. However, complex repairs may require a professional.
What are the most common causes of the B1987 code? Obstructions, faulty motors, wiring issues, and sensor problems are frequent culprits.
How do I test the pedal adjustment motor? You can directly apply voltage to the motor to see if it operates, but be sure to consult your vehicle's wiring diagram first.
Will the B1987 code affect my vehicle's safety? It can compromise driver comfort and potentially safety if the pedals are stuck in an uncomfortable or unsafe position.
Conclusion
The B1987 DTC indicates a malfunction in the pedal adjustment system, specifically a stalled motor. A systematic diagnostic approach, starting with visual inspections and progressing to more complex tests, is essential for identifying the root cause and implementing the appropriate repair, ensuring driver comfort and safety.