STEP 1. Using scan tool (M.U.T.-IIISE), check the data list.
STEP 2. Measure the resistance at the electric parking brake ECU connector and the electric parking brake switch connector.
(1) Disconnect the connector and measure at the wiring harness side.
(2) Measure the resistance between the electric parking brake ECU connector HSW terminal and the electric parking brake switch connector terminal No.8.OK: Continuity exists (2 ohms or less).
(3) Measure the resistance between the electric parking brake ECU connector HSW terminal and body ground.OK: No continuity.
Is the check result normal?
Go to Step 3. The signal circuit may be open or short to ground. Repair the wiring harness wires or connectors between the electric parking brake switch and the electric parking brake ECU.
STEP 3. Check the brake auto hold switch.
STEP 4. Retest the system
STEP 5. Measure the resistance at the electric parking brake ECU connector and the electric parking brake switch connector.
(1) Disconnect the connector and measure at the wiring harness side.
(2) Measure the resistance between the electric parking brake ECU connector HIND terminal and the electric parking brake switch connector terminal No.11.OK: Continuity exists (2 ohms or less).
(3) Measure the resistance between the electric parking brake ECU connector HIND terminal and body ground.OK: No continuity.
Is the check result normal?
Go to Step 6. The signal circuit may be open or short to ground. Repair the wiring harness wires or connectors between the electric parking brake switch and the electric parking brake ECU.
STEP 6. Measure the voltage at the electric parking brake switch connector.
(1) Disconnect the electric parking brake switch connector and measure at the wiring harness side.
(2) Measure the voltage between the terminal No.5 and body ground.OK: Battery voltage
Is the check result normal?
Go to Step 7. The power supply circuit may be open. Repair the wiring harness wires or connectors between the electric parking brake switch connector and the fusible link.
STEP 7. Check the brake auto hold Indicator.
STEP 8. Using scan tool (M.U.T.-IIISE), check the data list.
STEP 9. Retest the system