Inspection Procedure 16: Overdrive switch system




OPERATION



COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES
  • Malfunction of the overdrive switch
  • Damaged harness wires and connectors
  • Malfunction of the A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list
Item 26: Overdrive switch (Refer to data list reference table ).

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Go to Step 2.

STEP 2. Check the overdrive switch.
Refer to .

Q. Is the check result normal?
Go to Step 3.
Replace the high/low detection switch.

STEP 3. Measure the voltage at overdrive switch connector C-129.


(1)Disconnect the connector, and measure the voltage between terminal 3 and earth at the wiring harness side.
(2)Turn the ignition switch to the ON position.
OK: System voltage

Q. Is the check result normal?

Go to Step 6.

Go to Step 4.

STEP 4. Connector check: C-129 overdrive switch connector, C-209 J/B connector




Check for the contact with terminals.

Q. Is the check result normal?

Go to Step 5.

Repair the defective connector.

STEP 5. Check the harness between overdrive switch connector C-129 terminal No.3 and J/B connector C-209 terminal No.5.




Check the power supply line for short or open circuit.

Q. Is the check result normal?

Go to Step 6.

Repair the wiring harness.

STEP 6. Measure the voltage at A/T-ECU connector C-20.
(1)Disconnect high/low detection switch connector C-129.
(2)Turn the ignition switch to the ON position.
(3)Overdrive switch: ON.

(4)Measure the voltage between A/T-ECU connector C-20 terminal No.57 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 7.

Go to Step 8.

STEP 7. M.U.T.-III data list
Item 26: Overdrive switch (Refer to data list reference table ).

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

STEP 8. Connector check: C-129 overdrive switch connector, C-52 <LHD>or C-34 <RHD> intermediate connector, C-20 A/T-ECU connector





Check for the contact with terminals.

Q. Is the check result normal?

Go to Step 9.

Repair the defective connector.

STEP 9. Check the harness between overdrive switch connector C-129 terminal No.5 and A/T-ECU connector C-20 terminal No.57.



Check the power supply line for short or open circuit.

Q. Is the check result normal?

Go to Step 7.

Repair the wiring harness.