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Home >> Mazda >> 2011 >> RX-8 R3, 1.3 4 >> Repair and Diagnosis >> Engine Performance >> System >> On-Board Diagnostic [Engine Control System] >> DTC P0446
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DTC P0446

DTC P0446 EVAP system vent control circuit problem
DETECTION CONDITION 
  • The PCM monitors pump load current (EVAP line pressure) when the evaporative leak monitor is operating. If the decrease in pump load current is less than the specification after the reference current value has been obtained, the PCM determines that the change over valve in the EVAP system leak detection pump has a malfunction.

Diagnostic support note 
  • This is an intermittent monitor (EVAP system).
  • 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 (Mode 2/Mode 12) is available.
  • The DTC is stored in the PCM memory.
POSSIBLE CAUSE 
  • EVAP system leak detection pump connector or terminals malfunction
  • Change over valve malfunction (in EVAP system leak detection pump)
  • PCM connector or terminals malfunction
  • Short to power supply in wiring harness between EVAP system leak detection pump terminal C and PCM terminal 1V
  • PCM malfunction
G07878120
DIAGNOSTIC PROCEDURE

STEP INSPECTION ACTION
1 VERIFY FREEZE FRAME DATA (MODE 12) AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED 
  • Have the FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS (EVAP system related) been recorded?
 Yes Go to the next step.
No Record the FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2 VERIFY RELATED REPAIR INFORMATION AVAILABILITY 
  • Verify related Service Bulletins and/or on-line repair information availability.
  • Is any related repair information available?
 Yes Perform repair or diagnosis according to the available repair information.
  • If the vehicle is not repaired, go to the next step.
No Go to the next step.
3 INSPECT EVAP SYSTEM LEAK DETECTION PUMP CONNECTOR FOR POOR CONNECTION 
  • Turn the ignition switch off.
  • Disconnect the EVAP system leak detection pump connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
  • Is there any malfunction?
 Yes Repair or replace the connector and/or terminals, then go to Step 7.
No Go to the next step.
4 INSPECT CHANGE OVER VALVE (IN EVAP SYSTEM LEAK DETECTION PUMP) 
 Yes Replace the EVAP system leak detection pump, then go to Step 7.
(See EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM REMOVAL/INSTALLATION ).
No Go to the next step.
5 INSPECT PCM CONNECTOR FOR POOR CONNECTION 
  • Turn the ignition switch off.
  • Disconnect the PCM connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
  • Is there any malfunction?
 Yes Repair or replace the connector and/or terminals, then go to Step 7.
No Go to the next step.
6 INSPECT EVAP SYSTEM LEAK DETECTION PUMP CIRCUIT FOR SHORT TO POWER SUPPLY 
  • EVAP system leak detection pump and PCM connectors are disconnected.
  • Turn the ignition switch to the ON position (engine off).
  • Measure the voltage between EVAP system leak detection pump terminal C (wiring harness-side) and body ground.
  • Is the voltage B+? 
 Yes Repair or replace the wiring harness for a possible short to power supply, then go to the next step.
No Go to the next step.
7 VERIFY TROUBLESHOOTING OF DTC P0446 COMPLETED 
  • Make sure to reconnect all disconnected connectors.
  • Clear the DTC from the PCM memory using the M-MDS.

    (See AFTER REPAIR PROCEDURE ).

  • Perform the evaporative emission test using the M-MDS.

    (See ENGINE CONTROL SYSTEM OPERATION INSPECTION ).

  • Is the same DTC present?
    NOTE:
    • If the evaporative system test function is not available, perform the following procedure:
  • Perform the DRIVE MODE 6 (EVAP System Repair Verification Drive Mode).

    (See OBD-II DRIVE MODE ])

  • Is the PENDING CODE the same as the DTC present?
 Yes Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION ).
No Go to the next step.
8 VERIFY AFTER REPAIR PROCEDURE 
 Yes Go to the applicable DTC inspection.
(See DTC TABLE ).
No DTC troubleshooting completed.
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