Code No. P1A41: Main Battery Current Sensor (low) Abnormal






TROUBLE JUDGMENT
Check Conditions
  • The electric motor switch is "ON" position or while the main battery is charged.
  • The following diagnosis code is not set.

  1. P1A42: Power supply circuit of main battery current sensor abnormal
Judgement Criterion
  • The output voltage of the main battery current sensor (low) is less than 0.2 V.
or

  • The output voltage of the main battery current sensor (low) is more than 4.8 V.

FAIL-SAFE AND BACKUP FUNCTION

  • Use the main battery current sensor (high) to control and turn off the balancer drive when the main battery current sensor (high) is normal.

PROBABLE CAUSES

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

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-26 main battery connector

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

STEP 2. Check main battery current sensor itself.

  • Check main battery current sensor itself. (Refer to ).

Q. Is the check result normal?
Go to Step 3 .
Replace the main battery.

STEP 3. Perform resistance measurement at C-26 main battery connector.

  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 8 and earth.
OK: Continuity (2 Ω or less)

Q. Is the check result normal?
Go to Step 7 .
Go to Step 4 .

STEP 4. Connector check: C-109 BMU connector

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

STEP 5. Check harness between C-26 (terminal No. 8) main battery connector and C-109 (terminal No. 42) BMU connector



  • Check earthing line for open circuit and damage.

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

STEP 6. 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 7. Connector check: C-109 BMU connector

Q. Is the check result normal?
Go to Step 8 .
Repair.

STEP 8. Check harness between C-26 (terminal No. 2) main battery connector and C-109 (terminal No. 31) BMU connector



  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 9 .
Repair.

STEP 9. Perform voltage measurement at C-109 BMU connector

  • Measure BMU terminal voltage
  • Disconnect C-26 main battery connector
  • Electric motor switch: ON
  • Voltage between terminal No. 33 and earth.
OK: 0 - 0.1 V

Q. Is the check result normal?
Go to Step 10 .

    Check and repair harness between C-109 (terminal No. 33) BMU connector and C-26 (terminal No. 7) main battery connector.

    • Check output line for short circuit to power supply.

STEP 10. Check harness between C-26 (terminal No. 7) main battery connector and C-109 (terminal No. 33) BMU connector



  • Check output line for open circuit, short circuit to earth and damage.

Q. Is the check result normal?
Go to Step 11 .
Repair.

STEP 11. Perform resistance measurement at C-26 main battery connector.

  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 6 and earth.
OK: Continuity (2 Ω or less)

Q. Is the check result normal?
Go to Step 13 .
Go to Step 12 .

STEP 12. Check harness between C-26 (terminal No. 6) main battery connector and C-109 (terminal No. 43) BMU connector

  • Check the shield line for open circuit and damage.

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

STEP 13. 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 ).