Inspection Procedure 1: MCU power supply system



ELECTRIC MOTOR UNIT CONTROL SYSTEM CIRCUIT







PROBABLE CAUSES



  • Malfunction of the MCU
  • Open circuit, short circuit to earth system, damage, or connector poor contact in the MCU power supply circuit

DIAGNOSIS PROCEDURE


STEP 1. Connector check: E-06 MCU connector


Q. Is the check result normal?

Go to Step 2.
Repair the damaged connector.

STEP 2. Measure the voltage at E-06 MCU connector.


(1)Disconnect the connector and measure at the wiring harness side.
(2)Turn the electric motor switch to the ON position.
(3)Measure the voltage between the E-06 MCU connector No.5 and the earth.
OK: Battery voltage

Q. Is the check result normal?

Go to Step 4.

    Go to Step 3.

STEP 3. Check the wiring harness between E-06 MCU connector terminal No. 5 and B-112 joint connector.


Check the power supply line for open circuit and short circuit.
note Before the wiring harness check, check the C-102 intermediate connector and C-112 joint connector, then repair if necessary.

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .)
Repair the wiring harness.

STEP 4. Measure the resistance at E-06 MCU connector.


(1)Disconnect the connector and measure at the wiring harness side.
(2)Measure the resistance between the E-06 MCU connector terminal No. 10 and the body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 6.
Go to Step 5.

STEP 5. Check the wiring harness between E-06 MCU connector terminal No. 10 and the body earth.


Check the earth wires for open circuit.
note Before the wiring harness check, check the C-104 earth connector, and repair if necessary.

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .)
Repair the wiring harness.

STEP 6. Check the trouble symptom.


Check that the MCU function works normally.

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .)
Replace the MCU.