2000 Mazda B3000 SX, AutomaticFACTORY OEM SERVICE PROCEDURE

EVAP System Malfunction

DTC P0451, P0461 DETECTION CONDITION AND POSSIBLE CAUSE

DTC P0451, P0461 EVAP SYSTEM MALFUNCTION
DETECTION CONDITION 
  • P0451 indicates the fuel tank pressure changes greater than 14 in-H2O in 0.10 seconds (sensor circuit noisy).
  • P0461 indicates the fuel level input noisy.
POSSIBLE CAUSE 
  • Intermittent open or short in the FTP sensor circuit (P0451).
  • Intermittent open or short in the FLI circuit (P0461).
HINT  Fuel Tank Pressure Sensor Description 
  • Used to measures the fuel tank pressure during the EVAP monitor test and to control excessive fuel tank pressure by forcing the system to purge.

Fuel Level Input Description 
  • Indicates the fuel level in the tank.
  • Hard wire signal input to the PCM from the fuel pump (FP) module.
DTC P0451, P0461 INSPECTION

STEP INSPECTION ACTION
1 PCM QUICK TEST
  • Was PCM Quick Test performed? 
 Yes If any other DTC is present, go to applicable DTC Troubleshooting.
If only DTC P0451 and/or P0461 are present, refer to TEST 4: INTERMITTENT .
No Perform PCM Quick Test.
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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
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