Inspection Procedure 16: 4LLc operation detection switch system <4WD>
OPERATION
- A battery voltage is applied to the 4LLc operation detection switch output terminal (terminal 1) from the A/T-ECU (terminal 9) via the resistance in the unit.
- The 4LLc operation detection switch is grounded through the transfer case to the vehicle body.
COMMENTS ON TROUBLE SYMPTOM
PROBABLE CAUSES
- Malfunction of the 4LLc operation detection switch
- Damaged harness wires and connectors
- Malfunction of the A/T-ECU
DIAGNOSIS PROCEDURE |
STEP 1. M.U.T.-III data list |
Item 31: 4LLc operation detection 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 4LLc operation detection switch. |
| Refer to . |
Q.
Is the check result normal?
|
| Go to Step 3. |
|
| Replace the 4LLc operation detection switch. |
|
STEP 3. Measure the voltage at 4LLc operation detection switch connector B-05. |
| (1)Disconnect the connector, and measure the resistance between terminal 1 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 4. |
|
| Go to Step 5. |
|
STEP 4. M.U.T.-III data list |
| Item 31: 4LLc operation detection 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 5. Measure the voltage at A/T-ECU connector C-19. |
| (1)Disconnect 4LLc operation detection switch connector B-05. |
| (2)Turn the ignition switch to the ON position. |
| (3)Measure the voltage between A/T-ECU connector C-19 terminal No.9 and earth. OK: System voltage |
Q.
Is the check result normal?
|
| Go to Step 6. |
|
| Go to Step 8. |
|
STEP 6. Connector check: B-05 4LLc operation detection switch connector, A-115 and C-29 intermediate connector, C-19 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 4LLc operation detection switch connector B-05 terminal No.1 and A/T-ECU connector C-19 terminal No.9. |
| Check the power supply line for open circuit. |
Q.
Is the check result normal?
|
| Go to Step 4. |
|
| Repair the wiring harness. |
|
STEP 8. Connector check: B-05 4LLc operation detection switch connector, A-115 and C-29 intermediate connector, C-19 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 4LLc operation detection switch connector B-05 terminal No.1 and A/T-ECU connector C-19 terminal No.9. |
| Check the power supply line for short circuit. |
Q.
Is the check result normal?
|
| Go to Step 4. |
|
| Repair the wiring harness. |
|