Emissions - MIL ON/Multiple EVAP System DTC's Set
Engine01-030/03
2001-2005 Tribute, 1997-2004 B-Series - MIL ON
WITH DTCS P0442 P0455 P0456 P0457 P1442 OR CHECK
FUEL CAP LIGHT ON WITH DTC P0457
APPLICABLE MODEL(S)/VINS
2001-2005 Tribute
1997-2004 B-Series
DESCRIPTION
Some vehicles may exhibit a MIL (Malfunction Indicator Light) with DTC P0442, P0455, P0456, P0457 or P1442 or a Check Fuel Cap light illuminated with DTC P0457. These conditions may be caused by loose or leaking fuel cap or leaks anywhere in the evaporative emission system between the fuel tank and the engine.
NOTE:
^ Testing procedures described in this bulletin use the Mazda Evaporative Emission Tester P/N 134-01049. When using another tester follow the operating instructions for your tester.
^ Evaporative leaks may be caused by a loose, dirty or faulty fuel filler cap. Do not clean or replace the fuel filler cap until positively identifying it as the source of a leak through testing.
EVAPORATIVE VALVE OPERATION
The purging of fuel vapor stored in the charcoal canister is controlled by the EVAP charcoal canister where vapors are stored, one directs vapors to the intake manifold when the engine is running. So in order for this valve to purge vapors, the electronic valve must be commanded on by the PCM and the check valve must be opened by vacuum from a running engine.
PID = EVAPVM # )
A duty cycle of 0% = no flow and a duty cycle of 100% = full flow.
Electronic Vapor Management Valves are electronically controlled valves with only 2-ports: one leads to the EVAP charcoal canister where vapors are stored, one directs vapors to the intake manifold for combustion.
EVAPCV or EVAP Canister Vent valve: This valve mounted on or near the charcoal canister allows fresh air to be drawn into the fuel system to prevent fuel tank collapse during purging. It also allows the system to be sealed for leak testing the EVAP system.
PID EVAPCV # )
A duty cycle of 0% full flow or open to atmosphere and a duty cycle of 100% = no flow or closed for EVAP system testing.
NOTE:
This valve operation is exactly opposite the EVAP Canister Purge Valve and the Electronic Vapor Management Valve.
PROCEDURE 1:
Verifying A Very Small Leak (0.20" DTC P0456) Exists In The Evaporative Emission System Or After Repair Leak Test
NOTE:
^ Verify there is enough pressure in the gas bottle (only use inert gas such as Nitrogen or Argon) to perform testing (More than 670 kpa (100 psi)).
^ Verify there is adequate smoke generating fluid in the smoke machine reservoir.
^ Vehicle fuel tank must be between 1/4 and 3/4 full for accurate testing.
CAUTION:
Do not disturb the fuel filler cap or any other components in the evaporative emission system. Verify a leak exists before performing any repairs. A loose, leaking, improperly installed or dirty fuel filler cap can be the cause of a leak.
1. Test the evaporative emission system tester for leaks:
a. Position the control valve on the evaporative emission tester to the "TEST" position.
b. Place the tester hose on the "Self Test" fitting on the control panel.
c. Verify there are no leaks: the flow meter should indicate no flow (fixed at the bottom of the meter) if it is not fixed at the bottom, repair tester leaks before continuing.
2. Prepare the tester:
a. Adjust the regulated pressure using the (black) Low Pressure Regulator knob to 14 inches of water on the control panel pressure gauge.
b. Position the control valve on the evaporative emission tester to the "HOLD" position.
c. Remove the evaporative emission tester hose from the "Self-Test" port and connect it to the 0.20" calibrated leak orifice on the control panel of the Mazda Evaporative Emission Tester.
d. Position the control valve on the evaporative emission tester to the "TEST" position.
e. Observe the flow meter indicator ball. Position the flow meter flag so it aligns with the center of the indicator ball.
f. Position the control valve on the evaporative emission tester to the "HOLD" position.
g. Disconnect the tester hose from the 0.20 inch calibrated leak orifice.
3. Connect the tester hose to the EVAP Service Test Port on the vehicle.
NOTE:
Be careful when connecting the EVAP tester hose. On B-Series Trucks it is easy to cross thread due to the angle of the test fitting. On Tribute 2.3L be careful to route the EVAP tester hose so it does not contact the exhaust.
CAUTION:
Do not remove the schrader valve from either the EVAP Purge Valve or the Electronic Vapor Management valve, as this can permanently damage the valve.
4. Use WDS, ID the vehicle, then select Output State Control for Data logger PID, select the PID EVAPCV#) and at the bottom of the screen, select both MODE # ) and PER # ). Command the EVAP Canister Vent valve to 100% duty cycle to close it.
NOTE:
Perform testing and inspections efficiently. On some models, the EVAP Canister Vent valve may automatically open afier nine minutes of operation.
5. Position the control valve on the evaporative emission tester to the "TEST" position. NOTE: A leak free evaporative emission system will take less than 2-minutes to pressurize.
6. Determine whether the flow meter indicator ball is above or below the red indicator flag:
a. If the measurement is below the indicator flag, the system is leaking less than 0.20" and the system passed, go to STEP 7.
b. If the measurement is above the indicator flag, position the control valve on the evaporative emission tester to the "HOLD" position and locate any leaks by performing: PROCEDURE 2: Locating An Evaporative Emission System Leak Using Smoke.
7. Verify proper FTP sensor operation:
a. Position the control valve on the evaporative emission tester to the "HOLD" position.
b. Use WDS data logger and select the FTP (volts) PID.
c. Remove the fuel filler cap and turn the ignition switch to the run position.
d. Verify the FTP (volts) PID, it should be approximately 2.6 volts:
^ If FTP is greater than 2.8 volts or less than 2.4 volts, replace the FTP sensor and verify the FTP sensor operation from step "7a" above again.
^ If FTP is 2.6 volts, the sensor is in the correct range and the concern is not present.
e. Go to PROCEDURE 3: Checking The Canister Purge Valve For A No Flow Condition (P0455), and Checking FTP Sensor Operation
PROCEDURE 2: Locating An Evaporative Emission System Leak Using Smoke
NOTE:
Verify there is adequate smoke test fluid in the smoke tester reservoir.
1. Prepare for testing:
a. Locate the EVAP Canister Purge Valve or Electronic Vapor Management Valve in the engine compartment.
b. Identify the FUEL VAPOR TO INTAKE MANIFOLD hose and disconnect it.
2. Connect the Evaporative Emission system tester smoke machine battery cables to the vehicle's battery.
a. Press and hold the smoke button. The indicator ball in the flow meter will go all the way to the top indicating that the system is pressurizing.
b. Continue to hold the smoke button for 15 seconds or until the flow meter ball stops descending. It may take 3-5 minutes for the flow meter to settle (longer with lower fuel levels).
3. Position the control valve on the Mazda Evaporative Emission Tester to the "TEST" position.
4. Command the EVAP Canister Vent valve (EVAPCV # )) ON or 100% duty cycle.
NOTE:
Perform testing and inspections efficiently. On some models, you may lose pressure after nine minutes of CDCV operation. If this happens, repeat step 3 and 4 above then continue leak inspections.
5. If smoke begins to dissipate, press and hold the smoke button for 15 seconds.
6. Inspect the purge valve for leaks (especially the port of the hose which was disconnected in step 1):
^ If the purge valve leaks, stop testing and replace the purge valve before additional leak testing.
7. Check the rest of the evaporative emission system for leaks using the halogen test light:
a. Trace the hoses back from the engine compartment to the fuel tank and charcoal canister.
b. Wiggle lines and inspect areas in frame rails and on top of components.
c. Inspect around the charcoal canister, and the EVAP Canister Cut Valve.
d. Make sure to inspect for leaks at the Canister Drain Cut Valve fresh air inlet hose while the CDCV is closed. Locations vary see below:
^ 2001-2002 Tribute in the engine compartment near left front shock tower
^ 2003-2005 Tribute by the fuel filler neck
^ B-Series Truck inside the driver side frame rail near the charcoal canister
e. Inspect the fuel filler neck and valves and seals on top of the fuel tank.
8. After repairs are made, check for leaks using PROCEDURE 1: Verifying A Very Small Leak Exists In The Evaportive Emission System.
PROCEDURE 3: Checking The Canister Purge Valve For A No Flow Condition (P0455), and Checking FTP Sensor Operation
1. Warm the engine to operating temperature.
2. Using WDS: select Output State Control for Data logger PID, select the following PID's:
(EVAPVM # ) or EVMV # )), EVAPCV # ) and FTP volts. At the bottom of the screen, select both MODE # ) and PER # ) for all PIDs.
3. Start the vehicle.
4. Close the following valves using WDS:
a. EVAP Canister Vent valve: Switch the EVAPCV # ) ON or 100% duty cycle
b. EVAP Canister Purge Valve (EVAPVM # )) or Electronic Vapor Management Valve (EVMV#)): Switch it OFF or Zero% duty cycle or zero amps.
5. While monitoring the FTP volts PID on WDS:
^ Command the EVAP Canister Purge Valve (EVAPVM # )) or Electronic Vapor Management Valve (EVMV # )) ON or 100% duty cycle or 1.0 amp.
6. Determine condition:
^ If the FTP volts PID decreased and the engine RPM stumbles or the engine stalls, the test is passed, go to STEP 7.
^ If the engine RPM did not stumble or stall, replace the EVAP Vapor Management Valve and go to STEP 7.
^ If the FTP volts PID did not decrease (even if the engine RPM stumbles or the engine stalls), replace the FTP sensor and go to STEP 7.
7. Verify repair:
Perform an EVAP test using WDS or equivalent:
a. Select "Toolbox"
b. Select "Powertrain"
c. Select "Fuel"
d. Select "EVAP"
^ If test fails, return to PROCEDURE 1: Verifying A Very Small Leak Exists In The Evaporative Emission System Emission System Or After Repair Leak Test
^ If test passes, disconnect test equipment and return vehicle to customer.