FixVault

DTC P0505: Notes

WARNING: This page is about a different car, the 2007 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.
DETECTION CONDITION AND POSSIBLE CAUSE (DTC P0505)

DTC P0505 Idle speed control system problem
DETECTION CONDITION 
  • The PCM cannot control idle speed toward target idle speed while KOER self test.
POSSIBLE CAUSE 
  • Drive-by-wire control system malfunction
  • Air cleaner element clogged
  • Air intake passage clogged
  • A/C relay control circuit malfunction
  • Generator control circuit malfunction
  • Low engine compression (Over capacity of blow-by gas)
  • PCM malfunction