Code No. P1A3D: AD reference voltage abnormality (MCU)


ELECTRIC MOTOR UNIT CONTROL SYSTEM CIRCUIT



DIAGNOSIS CODE SET CONDITIONS



PROBABLE CAUSES



  • Unstable voltage of the auxiliary battery
  • Malfunction of the MCU

DIAGNOSIS PROCEDURE

STEP 1. Use M.U.T.-III to confirm a diagnosis code of other systems.
Check if the diagnosis code is set to the EV-ECU.

Q. Is the diagnosis code set?
Carry out troubleshooting for the EV-ECU. (Refer to .) Then go to Step 2.
Go to Step 2.

STEP 2. Measure the voltage at E-06 MCU connector.
(1)Disconnect the E-06 MCU connector, and measure the voltage 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 - the body earth.
OK: Battery voltage

Q. Is the check result normal?
Replace the MCU. (Refer to .) Then go to Step 5.
Go to Step 3.

STEP 3. Connector check: E-06 MCU connector, C-112 joint connector

Q. Is the check result normal?
Go to Step 4.
Repair the damaged connector.

STEP 4. Check the wiring harness between E-06 MCU connector terminal No. 5 and C-112 joint connector terminal No. 7.
Check the power supply line for open circuit.

Q. Is the check result normal?
Go to Step 5.
Repair the wiring harness.

STEP 5. Diagnosis code recheck
Check again if the diagnosis code is set to the MCU.
(1)Erase the stored diagnosis code.
(2)Set the electric motor switch from the "LOCK" (OFF) position to the "ON" position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?
The diagnosis is complete.
Return to Step 1.