Booster Pedal Force switch circuit Failure
Your vehicle's brake booster pedal force sensor isn't communicating properly with the engine computer, similar to a light switch that won't send a signal to turn the light on or off. This prevents the system from detecting how hard you're pressing the brake pedal.
The ECU monitors the booster pedal force switch circuit for proper voltage signals indicating brake pedal position and pressure application. The sensor should toggle between open and closed circuit states as pedal force changes, with the ECU detecting valid signal transitions within expected timeframes.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Switch Signal Voltage | 0V to 5V with clean transitions | No signal, stuck voltage, or erratic fluctuations |
| Circuit Resistance | Less than 5 ohms when closed, greater than 100k ohms when open | Out-of-range resistance or open/short circuit detected |
Code C1287 is classified as a serious fault. If your check engine light is flashing — not just steady — pull over safely and do not continue driving. A flashing CEL indicates an active misfire or critical failure that can cause catalytic converter damage within minutes or permanent engine harm within miles. Contact a certified mechanic immediately. Do not attempt roadside repairs on high-severity codes unless you are trained to do so.
Once the fault is repaired, C1287 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.