[23A] AUTOMATIC TRANSMISSION (FF) - - TROUBLESHOOTING <A/T> - DIAGNOSTIC TROUBLE CODE PROCEDURES <4G63, 4G64> - Code No.31: Low-Reverse Solenoid Valve System | PRINT PAGE / INDEX / PRIOR / NEXT

Code No.31: Low-Reverse Solenoid Valve System
OPERATION Solenoid valve closes or opens according to the signals from the engine-A/T-ECU. The engine-A/T-ECU energizes or deenergizes solenoid valve, based on input signals such as throttle position sensor opening angle, inhibitor switch, etc.
DIAGNOSIS CODE SET CONDITIONS If the drive terminal voltage of the low-reverse solenoid valve is 3.0 V or less, it is judged that there is a short circuit or open circuit in the low-reverse solenoid valve, and diagnosis code 31 is set. If diagnosis code 31 is output 4 times, the transmission is fixed in 3rd as a fail-safe measure.
PROBABLE CAUSES Malfunction of low-reverse solenoid valve Damaged harness wires and connectors Malfunction of the engine-A/T-ECU
DIAGNOSIS PROCEDURE
STEP 1. MUT-II/III diagnosis code Q: Is diagnosis code 36 set? YES: Go to Step 9. NO: Go to Step 2.
STEP 2. MUT-II/III actuator test Item 01: Low-reverse solenoid valve OK: Operating sound can be heard. Q: Is the check result normal? YES: Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ). NO: Go to Step 3.
STEP 3. Connector check: B-21 A/T control solenoid valve assembly connector Check for the contact with terminals. Q: Is the check result normal? YES: Go to Step 4. NO: Repair the defective connector.
STEP 4. Measure the resistance at A/T control solenoid valve assembly connector B-21. Disconnect the connector, and measure the resistance between terminal No.6 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? YES: Go to Step 5. NO: Check the low-reverse solenoid valve and solenoid valve harness.
STEP 5. Measure the voltage at engine-A/T-ECU connector C-109. Connect A/T control solenoid valve assembly connector B-21. Turn the ignition switch to the ON position. Measure the voltage between engine-A/T-ECU connector C-109 terminal No.129 and earth. OK: System voltage Q: Is the check result normal? YES: Go to Step 8. NO: Go to Step 6.
STEP 6. Connector check: C-109 engine-A/T-ECU connector Check for the contact with terminals. Q: Is the check result normal? YES: Go to Step 7. NO: Repair the defective connector.
STEP 7. Check the harness between A/T control solenoid valve assembly connector B-21 terminal No.6 and engine-A/T-ECU connector C-109 terminal No.129. Check the output line for short or open circuit. Q: Is the check result normal? YES: Go to Step 8. NO: Repair the wiring harness.
STEP 8. MUT-II/III actuator test Item 01: Low-reverse solenoid valve OK: Operating sound can be heard. Q: Is the check result normal? YES: Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ). NO: Replace the engine-A/T-ECU.
STEP 9. Connector check: B-21 A/T control solenoid valve assembly connector Check for the contact with terminals. Q: Is the check result normal? YES: Go to Step 10. NO: Repair the defective connector.
STEP 10. Measure the resistance at A/T control solenoid valve assembly connector B-21. Disconnect the connector, and measure the resistance between terminal No.6 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? YES: Go to Step 11. NO: Check the solenoid valve harness.
TEP 11. Connector check: B-16X A/T control relay connector Check for the contact with terminals. Q: Is the check result normal? YES: Go to Step 12. NO: Repair the defective connector.
STEP 12. Check the harness between A/T control solenoid valve assembly connector B-21 terminal No.10 and A/T control relay connector B-16X terminal No.1. Check the power supply line for short or open circuit. Q: Is the check result normal? YES: Go to Step 8. NO: Repair the wiring harness.

[23A] AUTOMATIC TRANSMISSION (FF) - - TROUBLESHOOTING <A/T> - DIAGNOSTIC TROUBLE CODE PROCEDURES <4G63, 4G64> - Code No.31: Low-Reverse Solenoid Valve System | PRINT PAGE / INDEX / PRIOR / NEXT

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