Code No. P0443: Purge Control Solenoid Valve System












OPERATION



  • Power is supplied to the purge control solenoid valve (terminal No. 2) from the engine control relay (terminal No. 2).
  • The engine-ECU (terminal No. 37) makes the power transistor in the unit be in ON position, and that makes currents go on the purge control solenoid valve (terminal No. 1).

FUNCTION



  • In response to a signal from the engine-ECU, the purge control solenoid valve controls the flow rate of the purge air to be introduced into the inlet manifold.

TROUBLE JUDGMENT


Check Conditions
  • Engine is being cranked.
  • Battery positive voltage is 10 - 16.5 V.
Judgment Criteria
  • The purge control solenoid valve coil surge voltage (battery positive voltage + 2 V) is not detected.
  • The engine-ECU monitors for this condition once during the drive cycle.
Check Conditions
  • Battery positive voltage is 10 - 16.5 V.
  • ON duty cycle of the purge control solenoid valve is 10 - 90 %.
  • More than 1 second has elapsed after the abovementioned conditions have been met.
Judgment Criterion
  • The purge control solenoid valve coil surge voltage (battery positive voltage + 2 V) is not detected for 1 second after the purge control solenoid valve is turned off.

PROBABLE CAUSES



  • Failed purge control solenoid valve
  • Open/short circuit or harness damage in purge control solenoid valve circuit or loose connector contact
  • Failed engine-ECU

DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III actuator test



  • Item 10: Purge control solenoid valve
OK: Operating sound can be heard and the valve vibrates

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 2 .

STEP 2. Connector check: B-31 purge control solenoid valve connector


Q. Is the check result normal?

Go to Step 3 .
Repair or replace the connector.

STEP 3. Perform resistance measurement at B-31 purge control solenoid valve connector.



  • Disconnect connector, and measure at solenoid valve side.
  • Resistance between terminal No. 1 and No. 2.
OK: 22 - 26 Ω (at 20°C)

Q. Is the check result normal?

Go to Step 4 .
Replace the purge control solenoid valve.

STEP 4. Perform voltage measurement at B-31 purge control solenoid valve connector.



  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 2 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 6 .
Go to Step 5 .

STEP 5. Connector check: A-33X engine control relay connector


Q. Is the check result normal?


    Check intermediate connector A-13, and repair if necessary. If intermediate connector is normal, check and repair harness between B-31 (terminal No. 2) purge control solenoid valve connector and A-33X (terminal No. 2) engine control relay connector.

    • Check power supply line for open/short circuit.
Repair or replace the connector.

STEP 6. Connector check: B-29 engine-ECU connector


Q. Is the check result normal?

Go to Step 7 .
Repair or replace the connector.

STEP 7. Check harness between B-31 (terminal No. 1) purge control solenoid valve connector and B-29 (terminal No. 37) engine-ECU connector.



  • Check output line for open/short circuit and damage.

Q. Is the check result normal?

Go to Step 8 .
Repair the damaged harness wire.

STEP 8. Check harness between B-31 (terminal No. 2) purge control solenoid valve connector and A-33X (terminal No. 2) engine control relay connector.


note Before checking harness, check intermediate connector A-13, and repair if necessary.

  • Check power supply line for damage.

Q. Is the check result normal?

Go to Step 9 .
Repair the damaged harness wire.

STEP 9. M.U.T.-III actuator test



  • Item 10: purge control solenoid valve
OK: Operating sound can be heard and the valve vibrates

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Replace the engine-ECU.