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Home >> Mitsubishi >> 1989 >> Galant L4-2.0L SOHC >> Repair and Diagnosis >> Powertrain Management >> Emission Control Systems >> Evaporative Emissions System >> Canister Purge Solenoid >> Testing and Inspection

Canister Purge Solenoid: Testing and Inspection

System Schematic:






To test the Purge Control Solenoid Valve, located on the engine compartment firewall, proceed as follows.


System Test

1. Mark and disconnect the vacuum hose (black with red stripe) from the solenoid valve and attach a hand vacuum pump.
2. Plug the vacuum nipple on the throttle body that the hose was removed from.
3. With the engine cold (below 60°C 140°F) and idling, apply 50 kPa (14.8 in.Hg) vacuum and verify that valve maintains vacuum.
4. Run engine at 3,000 RPM and repeat procedure, valve should still maintain vacuum.
5. Run engine until it reaches operating temperature (above 70°C 158°F) and let it idle.
6. Apply 50 kPa (14.8 in.Hg) vacuum and verify that valve maintains vacuum.
7. Stop engine and restart. Run engine at 3,000 RPM, within 3 minutes of starting engine repeat procedure, valve should leak vacuum.
8. Run engine at 3,000 RPM. 3 minutes after starting engine repeat procedure, valve should maintain vacuum momentarily and then leak.
Note: The vacuum will leak continuously if the altitude is 2,200m (7,200ft) or higher, or the intake air temperature is 50°C (122°F) or lower.


Component Test

1. Mark and disconnect the vacuum hose (black with red stripe) from the solenoid valve.
2. Disconnect the electrical harness connector.
3. Connect a manual vacuum pump to the nipple the red striped hose was removed from.
4. Attempt to apply a vacuum while voltage is applied to the solenoid valve, verify that the valve does not hold vacuum.
5. Remove power from the solenoid valve and verify that the solenoid valve holds vacuum.

6. Measure the resistance between the two terminals of the solenoid valve, and verify that the resistance is between 36 and 44 ohms at 20 degrees C (68 degrees F).

HARNESS TEST

1. Disconnect the solenoid connector and turn on the ignition.
2. Using a voltmeter, measure the power supply voltage between the harness connector terminal 2 and ground.

Voltage: System Voltage.

3. Turn off the ignition and disconnect the ECU connector. Using an Ohmmeter, check for continuity (short) to ground, between the ECU harness connector terminal 52 and the Purge Control Solenoid harness connector terminal 1.

Continuity: Should Not Exist.


4. Using an Ohmmeter, check for continuity between the ECU harness connector terminal 52 and the Purge Control Solenoid harness connector terminal 1.

Continuity: Should Exist.

If any of the previous tests produce unsatisfactory results, the harness will need to be repaired or replaced. Once repairs have been completed, road test the vehicle to confirm that the repair has corrected the problem.

If the same problem reoccurs, it is possible that there is an intermittent failure of the component or the ECU. Check for looseness at all harness junctions and test for an intermittent failure.

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