EVAP Canister Purge Valve Inspection
Caution: Do not breathe the air through the EVAP component tubes
or hoses. The fuel vapors inside the EVAP components may cause personal injury.
- Remove the EVAP canister purge valve. Refer to
Evaporative Emission Canister Purge Solenoid Valve Replacement
.
- Use a DMM in order to measure the resistance of the EVAP canister
purge valve.
Measure
The EVAP canister purge valve resistance should be 27-33 ohms
at 20°C (68°F).
- Replace the EVAP canister purge valve if the resistance is not
within the specified range. The solenoid will damage the powertrain control
module (PCM) if the resistance value is less than 27 ohms.
- Check the PCM and replace if necessary. Refer to
Powertrain Control Module Replacement
.
- Check for continuity of
each terminal to the valve body.
- Replace the EVAP canister purge valve if continuity is present.
- Blow air into the inboard
port (1). The air should NOT flow through the outboard port (2).
- Apply battery voltage across the terminals of the EVAP canister
purge valve.
- Blow air into the inboard port (1). The air should flow
easily to the outboard port (2).
- Replace the EVAP canister purge valve if the valve failed either
test. Refer to
Evaporative Emission Canister Purge Solenoid Valve Replacement
.
EVAP Pressure Switching Solenoid Inspection
Caution: Do not breathe the air through the EVAP component tubes
or hoses. The fuel vapors inside the EVAP components may cause personal injury.
- Remove the EVAP pressure
switching solenoid. Refer to
Evaporative Emission Pressure Switching Solenoid Replacement
.
- Use a DMM in order to measure the resistance of the EVAP pressure
switching solenoid.
Measure
The EVAP pressure switching solenoid resistance is 37-44 ohms
at 20°C (68°F).
- Replace the EVAP pressure switching solenoid if the resistance
is not within the specified range. The solenoid will damage the PCM, if the
resistance value is less than 27 ohms.
- Check for continuity on
each terminal to the valve body.
- Replace the EVAP pressure switching solenoid if continuity is
present. Refer to
Evaporative Emission Pressure Switching Solenoid Replacement
.
- Blow air into the inboard
port (1). The air should NOT flow through the valve and out of the
outboard port (2).
- Apply battery voltage across the terminals of the EVAP pressure
switching solenoid.
- Blow air into the inboard port (1) and air should flow
through the valve and out of the outboard port (2).
- Replace the EVAP pressure switching solenoid if the solenoid failed
either test. Refer to
Evaporative Emission Pressure Switching Solenoid Replacement
.
EVAP Canister Vent Valve Inspection
Caution: Do not breathe the air through the EVAP component tubes
or hoses. The fuel vapors inside the EVAP components may cause personal injury.
- Disconnect the EVAP vent solenoid electrical connector.
- Use a DMM in order the measure the solenoid resistance value.
Measure
The resistance should be between 25-30 ohms at 20°C
(68°F).
- Replace the solenoid if the resistance is not within the specified
range. Refer to
Evaporative Emission Canister Vent Solenoid Valve Replacement
.
- Use a DMM in order the
check for continuity between each solenoid terminal and solenoid housing.
Measure
The DMM has to read infinite (OL).
- Replace the EVAP vent solenoid valve if the resistance is not
within specification. A shorted valve will cause damage to the PCM.
- Blow air through the
inboard port (2) of the EVAP vent valve. Air has to flow freely through
the outboard port (1).
- Replace the valve if the air does not flow through the inboard
port (2). Refer to
Evaporative Emission Canister Vent Solenoid Valve Replacement
.
- Apply battery voltage
across the solenoid terminals.
- Blow air through the inboard port (1) of the solenoid.
Air should NOT flow through the valve.
- Replace the solenoid if the solenoid fails any of the tests. Refer
to
Evaporative Emission Canister Vent Solenoid Valve Replacement
.
Fuel Tank Pressure (FTP) Sensor Inspection
Tools Required
J 23738-A Hand Vacuum
Pump
- Disconnect the electrical
connector (4) from the fuel tank pressure (FTP) sensor .
- Turn ON the ignition, with the engine OFF.
- Measure the voltage between the 5-volt reference circuit (2)
and the sensor ground circuit (1) with a DMM.
Measure
The DMM should read 5.0 volts.
- If the measured voltage is not 5.0 volts for both tests,
inspect for the following conditions:
• | An open or a high resistance in the 5-volt reference circuit of
the FTP sensor . |
• | An open or high resistance in the ground circuit of the FTP sensor
. |
- Measure the voltage from
the input circuit (1) of the FTP sensor to ground with the DMM.
Measure
The DMM should read 4.5-5.5 volts.
- If the measured voltage is not 4.5-5.5 volts inspect
for the following conditions:
• | An open or high resistance in the input circuit of the FTP sensor
. |
• | A short in the input circuit of the FTP sensor. |
- Turn OFF the ignition.
- Connect the electrical connector to the FTP sensor .
- Disconnect the vacuum hose to the FTP sensor.
- Connect a hand held vacuum/pressure pump (1) to the FTP sensor.
- Select the DC scale on the DMM.
- Connect one lead to the input circuit at C221 of the FTP sensor
, and connect the other lead to ground.
- Measure the output voltage under the following conditions:
• | Apply a vacuum of 2.0 kPa (15 mm Hg, 0.59 in. Hg)
to the FTP sensor with a J 23738-A
or an equivalent hand vacuum pump. |
Measure
1.3-2.1 volts
• | Release the vacuum from the FTP sensor. |
Measure
3.0-3.6 volts
• | Apply a pressure of 1.5 kPa (0.22 psi) to the FTP sensor. |
Measure
4.2-4.8 volts
- Replace the FTP sensor if the measured voltage is not within the
test values listed above. Refer to
Fuel Tank Pressure Sensor Replacement
.
- Connect the vacuum hose to the FTP sensor .
EVAP Canister Inspection
Tools Required
J 23738-A Hand Vacuum
Pump
Caution: Do not breathe the air through the EVAP component tubes
or hoses. The fuel vapors inside the EVAP components may cause personal injury.
- Remove the EVAP canister. Refer to
Evaporative Emission Canister Replacement
.
- Plug the port (4).
- Hold the port plugged through the all tests.
- Hold the port (5) closed.
- Blow air with a pressure of 1.7 kPa (0.5 in Hg/0.25 psi)
into port (1).
- Verify that air flows out of port (2).
- Hold the port (5)
and the port (2) closed.
- Blow air with a pressure of 1.7 kPa (0.5 in Hg/0.25 psi)
into port (1).
- Verify that air does not flow out of the port (3).
- Hold the port (3)
closed.
- Apply a vacuum of 3.5 kPa (1.0 in Hg/0.5 psi)
to port (5) with a J 23738-A
or an equivalent hand vacuum pump.
- Verify that the vacuum holds if the port (3) is closed.
- Open the port (3) and check for vacuum release.
- Hold the port (3)
closed and apply 3.5 kPa (1.0 in. Hg/0.5 psi)
of vacuum to port (1) with the J 23738-A
or an equivalent hand vacuum pump.
- Check that air flows into the port (5).
- Replace the EVAP canister if the EVAP canister purge valve failed
the above tests.
- Remove the plug from the EVAP port.
- Install the EVAP canister. Refer to
Evaporative Emission Canister Replacement
.
EVAP System Inspection
- Visually inspect the EVAP
lines, the hoses, and the connection for the following:
• | Any sharp bends or kinks |
• | Any deformed lines and hoses |
• | Any incorrect routing of lines and hoses |
- Repair or replace any lines and hoses as necessary.
- Inspect the fuel filler cap gasket for damage.
- Visually inspect the EVAP
canister for cracks.
- Replace the EVAP canister if the canister is damaged. Refer to
Evaporative Emission Canister Replacement
.