MIL ON - P0442/P0455/P0456

Applicable Models

                                                                        
Some vehicles may exhibit a MIL ON condition with DTCs P0442, P0455,    
and/or P0456 stored in memory.  See the following list for possible     
causes.                                                                 
                                                                        
Capture freeze frame data, then clear all DTCs.  Run the WDS evaporative
system test to confirm the leak.  If vehicle fails, use the Mazda       
approved, EVAP Tester (Model #134-01049) to further diagnose.  Activate 
Mode 8 to manually close the Change Over Valve (COV).  Note that        
the purge solenoid valve is Normally Closed.  Run the gas leak test and 
the smoke test to confirm leak location.                                
                                                                        
On Mazda3, the following conditions have been found:                    
                                                                        
o STUCK OPEN PURGE SOLENOID VALVE - Confirm by removing purge           
  solenoid control valve hose at the intake manifold, then inspect      
  to see if smoke exits from the hose.  If smoke is seen, this          
  indicates a valve that is stuck open.                                 
                                                                        
  Note:  If hose is not removed, smoke may not be seen anywhere, and    
  it will appear the vehicle has no leak.                               
                                                                        
o MISSING "BASKET" SEAL - A smoke test will reveal if a basket seal     
  is missing from a quick disconnect fitting.                           
                                                                        
                                                                        
*** Published in M-tips newsletter Jan/Feb 2004.