Inspection Procedure 4: TC-SST-ECU Power Supply Circuit Malfunction

INSPECTION PROCEDURE 4: TC-SST-ECU power supply circuit malfunction

















CAUTION
Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

COMMENTS ON TROUBLE SYMPTOM
TC-SST-ECU power supply circuit, ground circuit, or TC-SST-ECU may have a problem.

PROBABLE CAUSES
^ Defective battery
^ Damaged harness wires and connectors
^ Malfunction of the ETACS-ECU
^ Malfunction of the shift lever-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Check the battery.

Q: Is the battery in good condition?
YES: Go to Step 2.
NO: Charge or replace the battery.

STEP 2. Measure the resistance at B-120 TC-SST-ECU connector.
Disconnect the connector, and measure the resistance between terminal No. 19 and ground at the wiring harness side.
OK: Continuity exists. (2 Ohms or less)

Q: Is the check result normal?
YES: Go to Step 5.
NO: Go to Step 3.

STEP 3. TC-SST-ECU connector check: B-120
Check for the contact with terminals.

Q: Is the check result normal?
YES: Go to Step 4.
NO: Repair the defective connector.

STEP 4. Check the wiring harness between B-120 TC-SST-ECU connector terminal No.19 and body ground.
Check the ground line for open circuit.

Q: Is the check result normal?
YES: Go to Step 5.
NO: Repair the wiring harness.

STEP 5. Measure the voltage at B-120 TC-SST-ECU connector.
Disconnect the connector, and measure the voltage between terminal No.6 and ground at the wiring harness side.
OK: Battery positive voltage

Q: Is the check result normal?
YES: Go to Step 8.
NO: Go to Step 6.

STEP 6. Inspection of the intermediate connector and TC-SST-ECU connector: A-54, B-120
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 wiring harness between B-120 TC-SST-ECU connector terminal No.6 and fusible link No.36.
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.

STEP 8. Scan tool diagnostic trouble code
Check the ETACS diagnostic trouble code.

Q: Is the DTC set?
YES: Perform the relevant troubleshooting.
NO: Go to Step 9.

STEP 9. Measure the voltage at B-120 TC-SST-ECU connector.
1) Disconnect the connector, and measure the voltage between terminal No.11 and ground at the wiring harness side.
2) Turn the ignition switch to the "ON" position.
OK: Battery positive voltage

Q: Is the check result normal?
YES: Go to Step 12.
NO: Go to Step 10.

STEP 10. Inspection of the intermediate connector, TC-SST-ECU connector, and ETACS-ECU connector: A-54, C-128, B-120, C-317
Check for the contact with terminals.

Q: Is the check result normal?
YES: Go to Step 11.
NO: Repair the defective connector.

STEP 11. Check the wiring harness between B-120 TC-SST-ECU connector terminal No.11 and C-317 ETACS-ECU connector terminal No.5.
Check the power supply line for short or open circuit.

Q: Is the check result normal?
YES: Go to Step 12.
NO: Repair the wiring harness.

STEP 12. Retest the system.

Q: Does a malfunction take place again?
YES: Replace the TC-SST assembly.
NO: Intermittent malfunction. (Refer to How to Cope with Intermittent Malfunction.)