Code No. P1A48: Output Circuit Of Main Battery Cooling Fan Relay 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
  • The PWM output signal of the main battery cooling fan is 100 % (while the fan is stopped) and the PWM output signal status of the main battery cooling fan is High (during the rotation).

FAIL-SAFE AND BACKUP FUNCTION

  • Not available

PROBABLE CAUSES

  • The main battery cooling fan is failed.
  • Short circuits to power supply system of main battery cooling fan circuit; poor contact of connector.
  • The BMU is failed.

DIAGNOSIS PROCEDURE

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

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

STEP 2. Perform voltage measurement at C-14 main battery cooling fan connector.

  • Disconnect the connector and measure the voltage at the female side.
  • Electric motor switch: ON
  • Voltage between terminal No. 2 and earth.
OK: 0 - 0.1 V

Q. Is the check result normal?
Go to Step 6 .
Go to Step 3 .

STEP 3. Connector check: C-107 BMU connector


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

STEP 4. 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 output line for short circuit to power supply.

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

STEP 5. M.U.T.-III diagnosis code.

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

STEP 6. M.U.T.-III diagnosis code.

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