B1486 – Brake Pedal Input Circuit Ground Short

The ODBII code B1486 indicates a short circuit to ground in the brake pedal input circuit, which can affect the vehicle’s braking system and related safety features.

The severity of ODBII code B1486 is moderate.

Common Causes For: B1485 Brake Pedal Input Circuit Battery Short

• Damaged wiring or connectors
• Faulty brake pedal position sensor
• Short circuit in the brake pedal input circuit
• Corroded or loose ground connections
• Malfunctioning brake control module
• Water intrusion or moisture in the circuit

Common misdiagnosis for B1486 Brake Pedal Input Circuit Ground Short

• Faulty brake pedal switch
• Wiring harness issues
• Faulty brake control module
• Shorted wiring or connectors
• Malfunctioning ABS module
• Incorrectly installed aftermarket components
• Faulty engine control module (ECM) or powertrain control module (PCM)

Common Troubleshooting Steps

When dealing with an OBD-II code B1486, which indicates a “Brake Pedal Input Circuit Ground Short,” it’s important to follow a systematic approach to troubleshoot the issue. Here are common troubleshooting steps:

• Scan Tool Verification:
• Use an OBD-II scanner to confirm the presence of the B1486 code. Check for any other related codes that may provide additional context.
• Visual Inspection:
• Inspect the wiring and connectors related to the brake pedal input circuit. Look for signs of damage, corrosion, or loose connections.
• Check the brake pedal switch for proper installation and condition.
• Check Brake Pedal Switch:
• Test the brake pedal switch for proper operation. This can usually be done by checking for continuity when the brake pedal is pressed and released.
• If the switch is faulty, replace it.
• Inspect Ground Connections:
• Locate the ground connections associated with the brake pedal input circuit. Ensure they are clean, tight, and free of corrosion.
• Use a multimeter to check for continuity between the ground point and the vehicle’s chassis.
• Wiring Inspection:
• Trace the wiring from the brake pedal switch to the Engine Control Module (ECM) or Body Control Module (BCM). Look for any signs of shorts, frays, or breaks in the insulation.
• Use a multimeter to check for shorts to ground in the wiring.
• Check for Shorts:
• With the vehicle off, use a multimeter to check for continuity between the brake pedal input circuit wire and ground. If there is continuity, there is a short to ground that needs to be addressed.
• Test the Circuit:
• With the vehicle on, use a multimeter to measure the voltage at the brake pedal switch. Ensure that it is receiving the correct voltage and that the output signal is functioning as expected when the pedal is pressed.
• Inspect Related Components:
• Check other components that may be related to the brake system, such as the ABS module or traction control system, as they may also affect the brake pedal input circuit.
• Clear Codes and Test Drive:
• After addressing any issues found, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Consult Service Manual:
• If the issue persists, consult the vehicle’s service manual for specific diagnostic procedures and wiring diagrams related to the brake pedal input circuit. 1
• Professional Help:
• If you are unable to resolve the issue, consider seeking help from a professional mechanic or automotive technician who has experience with electrical systems. By following these steps, you should be able to identify and resolve the issue causing the B1486 code.