2006 Mazda MX-5 Miata BaseFACTORY OEM SERVICE PROCEDURE

DTC P0446: Notes

DETECTION CONDITION AND POSSIBLE CAUSE (DTC P0446)

DTC P0446 Change over valve (COV) (EVAP system leak detection pump) stuck close
DETECTION CONDITION 
  • The PCM monitors pump load current (EVAP line pressure), while evaporative leak monitor is operating. When the decrease in pump load current is less than the specification after the reference current value has been obtained, the PCM determines change over valve (COV) in EVAP system leak detection pump has a malfunction.
Diagnostic support note 
  • This is an intermittent monitor (CCM).
  • The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
  • PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
  • FREEZE FRAME DATA is available.
  • The DTC is stored in the PCM memory.
POSSIBLE CAUSE 
  • Damaged COV (in EVAP system leak detection pump.)
  • Short to power circuit between the EVAP system leak detection pump terminal C and PCM terminal 1 V
  • Damaged PCM
G04317722Courtesy of MAZDA MOTORS CORP.
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