P0421MinorVehicle Speed and Idle Control

Code P0421 — Vehicle Speed and Idle Control

Diagnostic trouble code P0421 indicates a fault in the Vehicle Speed and Idle Control system. This code is detected by the vehicle's onboard diagnostic system and requires professional diagnosis.

Common Causes

  • ▸Faulty sensor or wiring
  • ▸Software or calibration issue
  • ▸Mechanical component failure