Code No.P1777 (P0770) Reduction solenoid valve system <5A/T>


SOLENOID VALVE SYSTEM CIRCUIT



OPERATION



DIAGNOSIS CODE SET CONDITIONS




PROBABLE CAUSES



  • Malfunction of reduction solenoid valve
  • Damaged harness wires and connectors
  • Malfunction of the A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q. Are diagnosis codes P1773 (P0750) and P1778 (P0740) set?
Go to Step 9.
Go to Step 2.

STEP 2. M.U.T.-III actuator test
Item 5: Reduction solenoid valve
OK: Operating sound can be heard.

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Go to Step 3.

STEP 3. Connector check: B-15 A/T control solenoid valve assembly connector
Check for the contact with terminals.

Q. Is the check result normal?
Go to Step 4.
Repair the defective connector.

STEP 4. Measure the resistance at A/T control solenoid valve assembly connector B-15.
Disconnect the connector, and measure the resistance between terminal No.8 and No.10 at the solenoid valve side.
OK: 2.7 - 3.4 Ω (A/T fluid temperature 20°C)

Q. Is the check result normal?
Go to Step 5.
Check the reduction solenoid valve and solenoid valve harness.

STEP 5. Measure the voltage at A/T-ECU connector C-20.
(1)Connect A/T control solenoid valve assembly connector B-15.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between A/T-ECU connector C-20 terminal No.51 and earth.
OK: 6 - 9 V

Q. Is the check result normal?
Go to Step 8.
Go to Step 6.

STEP 6. Connector check: B-11 intermediate connector, C-20 A/T-ECU connector
Check for the contact with terminals.

Q. Is the check result normal?
Go to Step 7.
Repair the defective connector.

STEP 7. Check the harness between A/T control solenoid valve assembly connector B-15 terminal No.8 and A/T-ECU connector C-20 terminal No.51.
Check the output line for short or open circuit.

Q. Is the check result normal?
Go to Step 8.
Repair the wiring harness.

STEP 8. M.U.T.-III actuator test
Item 5: Reduction solenoid valve
OK: Operating sound can be heard.

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Replace the A/T-ECU.

STEP 9. Connector check: B-15 A/T control solenoid valve assembly connector
Check for the contact with terminals.

Q. Is the check result normal?
Go to Step 10.
Repair the defective connector.

STEP 10. Measure the resistance at A/T control solenoid valve assembly connector B-15.
Disconnect the connector, and measure the resistance between terminal No.8 and No.10 at the solenoid valve side.
OK: 2.7 - 3.4 Ω (A/T fluid temperature 20°C)

Q. Is the check result normal?
Go to Step 11.
Check the solenoid valve harness.

STEP 11. Connector check: A-19X A/T control relay connector, B-10 intermediate connector
Check for the contact with terminals.

Q. Is the check result normal?
Go to Step 12.
Repair the defective connector.

STEP 12. Check the harness between A/T control solenoid valve assembly connector B-15 terminal No.10 and A/T control relay connector A-19X terminal No.3.
Check the power supply line for short or open circuit.

Q. Is the check result normal?
Go to Step 8.
Repair the wiring harness.