Code No. P1AC3: Main Battery Cooling Fan Failed (stop abnormal)






TROUBLE JUDGMENT
Check Conditions
  • The main battery cooling fan relay is turned ON.
  • The following diagnosis codes are not set.

  1. P1A47: Power supply of main battery cooling fan relay abnormal (short circuits to power supply system, open circuits)
  2. P1A4E: Power supply of main battery cooling fan relay abnormal (short circuits to earth system)
Judgement Criterion
  • For more than 5 seconds, the PWM output signal of the main battery cooling fan is 100 % (while the fan stops). The output of the rotational speed is more than 0.7 V (more than 493 r/min or equivalent).

FAIL-SAFE AND BACKUP FUNCTION

  • Not available

PROBABLE CAUSES

  • The main battery cooling fan is failed.
  • Open circuits of main battery cooling fan relay circuit, short circuits to power supply system or damage; poor contact of connector.
  • The BMU is failed.

DIAGNOSIS PROCEDURE


STEP 1. Connector check: C-107 BMU connector, C-14 main battery cooling fan connector

Q. Is the check result normal?
Go to Step 2 .
Repair.

STEP 2. Check harness between C-14 (terminal No. 2) main battery cooling fan connector and C-107 (terminal No. 13) BMU connector
note Before checking harness, check intermediate connector C-102, and repair if necessary.

  • Check signal line for open circuit and damage.

Q. Is the check result normal?
Go to Step 3 .
Repair.

STEP 3. Perform voltage measurement at C-107 BMU connector

  • Measure the BMU terminal voltage.
  • Disconnect C-14 main battery cooling fan connector.
  • Electric motor switch: ON
  • Voltage between terminal No. 21 and earth.
OK: 0 - 0.1 V

Q. Is the check result normal?

    Check intermediate connector C-102, and repair if necessary. If intermediate connector is normal, check and repair harness between C-14 (terminal No. 3) main battery cooling fan connector and C-107 (terminal No. 21) BMU connector.

    • Check output line for short circuit to power supply.
Go to Step 4 .

STEP 4. M.U.T.-III diagnosis code

Q. Is the diagnosis code set?
Go to Step 5 .
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 5. After replacing the main battery, reconfirm the diagnosis code.

  • After replacing the main battery, reconfirm whether the diagnosis codes are set.

Q. Is the diagnosis code set?
Replace the BMU.
Check end.