DTC P0442, P0455, P0456

DTC P0442	P0442: EVAP system leak detected (small leak)
DTC P0455	P0455: EVAP system leak detected (gross leak/no flow)
DTC P0456	P0456: EVAP system leak detected (very small leak)
DETECTION CONDITION	The PCM measures the pump load current (EVAP line pressure) after a specified period has elapsed since the EVAP system is sealed when monitoring conditions are met. If the load does not reach the reference load value, or the rate of the load increase is lower than the specification within a specified period, the PCM determines that the EVAP system has a very small leak. MONITORING CONDITIONS The ignition switch is turned off. IAT: 5-35°C {41-95°F} Battery voltage: 10.9 V or above Atmospheric pressure: 72.2 kPa {542 mmHg, 21.3 inHg} or above Fuel tank level: 15-85% Time from engine off: 5 h or more Diagnostic support note This is an intermittent monitor (EVAP system). The MIL illuminates if the PCM detects 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	DTC P0442, P0456 After-market EVAP hardware (such as fuel-filler cap) not conforming to required specifications Small holes or cuts in fuel vapor hoses/tubes Change over valve stays partially open on closed command Damaged, cross-threaded or loosely installed fuel-filler cap EVAP system component seals leaking Purge solenoid leaking DTC P0455 After-market EVAP hardware (such as fuel-filler cap) not conforming to required specifications Disconnected or cracked change over valve, purge solenoid valve outlet tube, or EVAP return tube. Loose, malfunctioning, damaged or missing fuel-filler cap Loose fuel vapor hose/tube connections to EVAP system components Change over valve stuck open Damaged charcoal canister

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.
1		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. Are any related Service Bulletins available?	Yes	Perform repair or diagnosis according to the available Service Bulletins. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	VERIFY RELATED PENDING CODE AND STORED DTC Turn the ignition switch off then to the ON position (Engine off). Verify related PENDING CODE and stored DTC. Are any other DTCs present?	Yes	Go to the appropriate DTC troubleshooting. (See DTC TABLE ).
3		No	Go to the next step.
4	PRELIMINARY EVAP SYSTEM TEST Perform the EVAP system leak inspection using the M-MDS. Verify that all PIDs are within the following specifications: NOTE: To successfully perform this procedure, all PIDs must be within specification before proceeding to the next step. Select the following items from the initialization screen of the M-MDS. Select "Powertrain". Select "Fuel". Select "EVAP Test". Verify that ECT and IAT are within the specification on the confirmation screen. To successfully perform this procedure, ECT and IAT must be within the specification before proceeding to the next step. The fuel level must be maintained within 15%-85% . The PCM will cancel the EVAP test If the fuel level is lower than 15% or higher than 85% . Allow the M-MDS to run the EVAP test. Are DTCs besides P0455, P0442 or P0456 present?	Yes	Go to the appropriate DTC troubleshooting. (See DTC TABLE ).
4		No	Go to the next step.
5	VERIFY EVAP DTCs Did the M-MDS EVAP test produce DTCs P0455, P0442 or P0456?	Yes	Go to the next step.
5		No	Go to Step 8.
6	SECONDARY EVAP SYSTEM TEST Tighten the fuel-filler cap then perform the EVAP system leak inspection using the M-MDS again. Verify that all PIDs are within the following specifications: NOTE: To successfully perform this procedure, all PIDs must be within the specification before proceeding to the next step. Select the following items from the initialization screen of the M-MDS. Select "Powertrain". Select "Fuel". Select "EVAP Test". Verify that ECT and IAT are within the specification on the confirmation screen. To successfully perform this procedure, ECT and IAT must be within the specification before proceeding to the next step. The fuel level must be maintained within 15%-85% . The PCM will cancel the EVAP test If the fuel level is lower than 15% or higher than 85% . Allow the M-MDS to run the EVAP test. Does the M-MDS still indicate that an EVAP system leak exists?	Yes	Go to the next step.
6		No	Fuel-filler cap was not properly tightened. Go to Step 11.
7	VISUALLY INSPECT COMPONENTS FOR LEAKS Visually inspect for cut or loose connections to the fuel vapor hoses/tubes in the following locations: Charcoal canister to EVAP leak detection pump Charcoal canister to evaporative emission valve component Evaporative emission valve component to the fuel tank (if applicable) Check for fuel-filler pipe damage Is a concern with a hose, tube, connection or valve visually evident?	Yes	Repair or install a new component if necessary. Afterwards, verify that the leak is repaired by performing diagnostic Step 8.
7		No	Go to the next step.
8	CALIBRATE THE LEAK TESTER FOR DIAGNOSIS Verify that the control valve on the panel is in the HOLD position then open the nitrogen bottle valve. Connect the vehicle interface hose (part of the SST) to the SELF-TEST port located on the control panel. Hand tighten the fitting. (Do not overtighten). Turn the control valve to the TEST position; the gauge should read 331-381 mm {13-15 in} of water. NOTE: If the gauge is not reading in this range, adjust the pressure by turning the black knob on the low pressure regulator at the nitrogen bottle. After verifying the regulator is properly calibrated, turn the control valve to the HOLD position. Verify that the gauge holds pressure and that the flow meter reads no flow. Does the gauge hold pressure and the flow meter read no flow?	Yes	Go to the next step.
8		No	Refer to the tester operator's manual for tester repair instructions.
9	PRESSURIZE THE EVAP SYSTEM WITH NITROGEN Verify that the control valve on the panel is in the HOLD position. Remove the fuel-filler cap from the vehicle. If the fuel-filler cap is not a MAZDA part or equivalent, replace it. NOTE: INSPECT FUEL-FILLER CAP AND FILLER NECK Visually inspect for damage, insufficient sealing, rust, cracks or warps for fuel-filler cap and fuel-filler neck Repair or replace if necessary Connect the receiver assembly (SST : 134-01051) to the vehicle cap test hose assembly (part of the SST ) and the fuel-filler cap from the vehicle. Connect the cap adaptor (SST : 134-01050) to the vehicle cap test hose assembly (part of the SST ) and to the fuel-filler neck. Connect the vehicle interface hose (part of the SST ) to the center fitting of the vehicle cap test hose assembly (part of the SST ). Connect M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Request PCM on-board device control (Mode 08) using M-MDS to close the change over valve. NOTE: The change over valve is closed for 10 min unless either of the following is done: The engine is started. The ignition switch is turned to the off position. Verify the valve on the nitrogen bottle is still open. Turn the control valve to the open position and let the system fill. You should note a drop in the gauge pressure along with the flow meter being pegged at maximum flow for several minutes depending on how full or empty the fuel tank is, and how long it takes to completely fill and pressurize the evaporative emissions system hoses. Does the test indicate that a leak exists?	Yes	Disconnect the purge solenoid valve hose (to intake manifold side), then go to the next step.
9		No	Go to Step 11.
10	LOCATE LEAKAGE POINT Verify that the control valve on the panel is in the HOLD position and the valve on the nitrogen bottle is open. Connect the 12 volt power connector leads on the smoke generation unit to the vehicle's battery. Make sure to connect the red lead to the positive (+) terminal or power, and black lead to vehicle's chassis ground. Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off) Request PCM on-board device control (Mode 08) using the M-MDS to close the change over valve. NOTE: The change over valve is closed for 10 min unless either of the following occur: The engine is started. The ignition switch is turned to the off position. Turn the control valve to the open position. NOTE: NEVER depress the remote smoke trigger before opening the nitrogen tank valve and setting the tester control valve to TEST. Press the remote smoke trigger on the smoke generation unit and let the system fill with smoke. NOTE: It may be necessary to lift the vehicle to provide sufficient clearance underneath to conduct a proper visual inspection of the fuel and EVAP system. Use a 12-volt, 400, 000 candle power spotlight (part # 4410000-100) or equivalent to help locate the smoke. Is a leak detected?	Yes	Repair or install a new component if necessary, then go to the next step.
10		No	Check all EVAP connections. Conduct diagnosis of intermittent concerns, then go to the next step.
11	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE ). Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE ).
11		No	DTC troubleshooting completed.