Evaporative Emission Control System Diagnosis w/o ORVR

Caution: Do not breathe the air through the EVAP component tubes or hoses. The fuel vapors inside the EVAP components may cause personal injury.

Important: Perform a careful visual inspection of the evaporative emission (EVAP) control system components and the connecting hoses before diagnosis of an EVAP system malfunction.

Important: The EVAP canister purge system does not perform purging unless the engine is sufficiently warmed up and the heated oxygen sensor (HO2S) is fully activated.

1. Allow the engine to cool to room temperature.
2. Start the engine.
3. Disconnect the purge hose from the EVAP canister.
4. Place a finger against the end of the disconnected hose and check for vacuum. Vacuum should not be felt when the engine coolant temperature is less than the normal operating temperature.
5. Connect the purge hose to the EVAP canister and warm the engine up to a normal operating temperature.
6. Disconnect the purge hose from the EVAP canister.
7. Place a finger over the disconnected hose and check for vacuum. Vacuum should be felt with the engine running at a normal operating temperature and at 1,500 RPM.

1. Disconnect the vacuum hoses from the EVAP canister.
2. Blow air into the tank pipe of the EVAP canister. There should be no restriction of air flow through the purge pipe and the air pipe.
3. Replace the EVAP canister if the EVAP canister fails the above inspection. Refer to Evaporative Emission Canister Replacement .
4. Connect the vacuum hoses to the EVAP canister.

1. Disconnect the electrical connector from the EVAP canister purge valve .
2. Using a digital multimeter (DMM) (1), measure the resistance of the EVAP canister purge valve (2) between both terminals. The resistance should be 28-36 ohms at 20°C (68°F).
3. Replace the EVAP canister purge valve if the resistance is not 28 to 36 ohms at 20°C (68°F). If the resistance is within specification, proceed to Step 4.



4. Disconnect the purge valve vacuum hoses from the intake manifold and the vacuum pipe from the EVAP canister.
5. Blow air into the purge valve vacuum hose that was disconnected from the vacuum pipe. Air should NOT pass through the EVAP canister purge valve and exit from the intake manifold hose.
6. Connect 12 volts DC to the terminals of the EVAP canister purge valve.
7. Blow air into the purge valve vacuum hose that was disconnected from the EVAP canister. Air should pass through the EVAP canister purge valve and exit from the intake manifold hose.
8. Replace the EVAP canister purge valve if the EVAP canister purge valve failed this inspection. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .
9. Connect the purge valve vacuum hoses and the electrical connector.

1. Remove the EVAP canister vent valve. Refer to Evaporative Emission Canister Vent Solenoid Valve Replacement .
2. Using a DMM, measure the resistance of the EVAP canister vent valve between both terminals. The resistance should be 25-30 ohms at 20°C (68°F).
3. Replace the EVAP canister vent valve if the resistance is not 25-30 ohms at 20°C (68°F). If the resistance is within specification, proceed to Step 4.



4. Disconnect the EVAP canister vent valve hose from the EVAP canister.
5. Blow air into the vent valve hose that was disconnected from the EVAP canister. Air should pass through the EVAP canister vent valve.



6. Connect 12 volts DC to the terminals of the EVAP canister vent valve .
7. Blow air into the vent valve vacuum hose that was disconnected from the EVAP canister. Air should not pass through the vent valve and exit from the other end.
8. Replace the EVAP canister vent valve if the vent valve failed this inspection. Refer to Evaporative Emission Canister Vent Solenoid Valve Replacement .
9. Connect the vent valve vacuum hoses and the electrical connector.

1. Disconnect the electrical connector from the EVAP tank pressure control valve.
2. Using a DMM, measure the resistance of the pressure control valve between both terminals. The resistance should be 28-36 ohms at 20°C (68°F).
3. Replace the pressure control valve if the resistance is not 28-36 ohms at 20°C (68°F). If the resistance is within specification, proceed to Step 4.



4. Disconnect the EVAP tank pressure control valve vacuum hoses from the intake manifold and the vacuum pipe from the fuel tank pressure control valve.
5. Blow air into the EVAP tank pressure control valve vacuum hose that was disconnected from the vacuum pipe. Air should not pass through the EVAP tank pressure control valve and exit from the intake manifold hose.



6. Connect 12 volts DC to the terminals of the EVAP tank pressure control vacuum valve .
7. Blow air into the EVAP tank pressure control valve vacuum hose that was disconnected from the vacuum pipe. Air should pass through the EVAP tank pressure control valve and exit from the intake manifold hose.
8. Replace the EVAP tank pressure control valve if the EVAP tank pressure control solenoid valve failed this inspection. Refer to Evaporative Emission Tank Pressure Control Solenoid Valve Replace .
9. Connect the EVAP tank pressure control valve vacuum hoses and the electrical connector.

1. Connect a length of the hose to the fuel tank pressure control valve vacuum port marked TANK.
2. Blow hard into the hose. Air should pass slowly through to the side marked CAN of the fuel tank pressure control valve (1).
3. Remove the hose from the TANK side and connect it to the CAN side of the fuel tank pressure control valve.
4. Blow easily into the hose. Air should pass through to the side marked TANK of the fuel tank pressure control valve (2).
5. Use a J 23738-A Vacuum Pump in order to apply the vacuum to the vacuum port.
6. With vacuum applied, blow into the hose marked TANK. Air should pass easily through to the side marked CAN of the fuel tank pressure control valve (3).
7. Replace the fuel tank pressure control valve if the valve fails any of the above inspections. Refer to Fuel Tank Pressure Control Valve Replacement .

Evaporative Emission Control System Diagnosis with ORVR

Caution: Do not breathe the air through the EVAP component tubes or hoses. The fuel vapors inside the EVAP components may cause personal injury.

Important: Perform a careful visual inspection of the evaporative emission (EVAP) control system components and the connecting hoses before diagnosis of an EVAP system malfunction.

Important: The EVAP canister purge system does not perform purging unless the engine is sufficiently warmed up and the heated oxygen sensor (HO2S) is fully activated.

1. Allow the engine to cool to room temperature.
2. Start the engine.
3. Disconnect the purge hose from the EVAP canister.
4. Place a finger against the end of the disconnected hose and check for vacuum. Vacuum should not be felt when the engine coolant temperature is less than the normal operating temperature.
5. Connect the purge hose to the EVAP canister and warm the engine up to a normal operating temperature.
6. Disconnect the purge hose from the EVAP canister.
7. Place a finger over the disconnected hose and check for vacuum. Vacuum should be felt with the engine running at a normal operating temperature and at 1,500 RPM.

1. Disconnect the vacuum hoses from the EVAP canister.
2. Blow air into the tank port (1) of the EVAP canister. There should be no restriction of air flow through the purge pipe (2) and the air port (3).
3. Replace the EVAP canister if the EVAP canister fails the check above. Refer to Evaporative Emission Canister Replacement .
4. Connect the vacuum hoses to the EVAP canister.

1. Disconnect the electrical connector from the EVAP canister purge valve .
2. Using a digital multimeter (DMM) measure the resistance of the EVAP canister purge valve between both terminals. The resistance should be 28-36 ohms at 20°C (68°F).
3. Replace the EVAP canister purge valve if the resistance is not 28-36 ohms at 20°C (68°F). If the resistance is within specification, proceed to Step 4.
4. Disconnect the purge valve vacuum hoses.
5. Blow air into the lower port of the purge valve. Air should NOT pass through the EVAP canister purge valve and exit from the upper port.



6. Connect 12 volts DC to the terminals of the EVAP canister purge valve.
7. Blow air into the lower port (1) of the purge valve. Air should pass through the EVAP canister purge valve and exit from the upper port (2).
8. Replace the EVAP canister purge valve if the valve failed this inspection. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .
9. Connect the purge valve vacuum hoses and the electrical connector.

1. Remove the EVAP canister vent valve. Refer to Evaporative Emission Canister Vent Solenoid Valve Replacement .



2. Using a DMM, measure the resistance of the EVAP canister vent valve between both terminals. The resistance should be 25-30 ohms at 20°C (68°F).
3. Replace the EVAP canister vent valve if the resistance is not 25-30 ohms at 20°C (68°F). If the resistance is within specification, proceed to Step 4.



4. Blow air into the vent valve port that was connected to the EVAP canister air filter. Air should pass through the EVAP canister vent valve.



5. Connect 12 volts DC to the terminals of the EVAP canister vent valve .
6. Blow air into the vent valve port that was connected to the EVAP canister air filter. Air should not pass through the vent valve and exit from the other end.
7. Replace the EVAP canister vent valve if the vent valve failed this inspection.
8. Install the EVAP canister vent valve. Refer to Evaporative Emission Canister Vent Solenoid Valve Replacement .

Important: The fuel tank pressure control valve that is original equipment manufacture (OEM) is black on the fuel tank side port, and orange on the canister side port.

1. Connect a hose to the fuel tank side of the pressure control valve on the fuel tank.
2. Blow hard into the hose. Some air should pass through the valve from the fuel tank side to the canister side when blown hard.



3. Remove the hose from the fuel tank side, and connect the hose to the canister side of the pressure control valve.
4. Blow easily into the hose. Even lightly blown air should pass smoothly through the valve from the canister side to the fuel tank side.
5. Replace the fuel tank pressure control valve if the valve fails any of the above inspections. Refer to Fuel Tank Pressure Control Valve Replacement .