Code No. P1A42: Power Supply Circuit Of Main Battery Current Sensor Abnormal

TROUBLE JUDGMENT

Check Condition

The electric motor switch is "ON" position or while the main battery is charged.

Judgement Criterion

The power supply voltage of the main battery current sensor is more than 5.3 V.

or

The power supply voltage of the main battery current sensor is less than 4.7 V.

FAIL-SAFE AND BACKUP FUNCTION

Turn off the balancer drive.

PROBABLE CAUSES

The main battery current sensor is failed.
Open circuits of main battery current sensor circuit, short circuits to earth 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. Perform voltage measurement at C-26 main battery connector.

Disconnect connector, and measure at harness side.
Electric motor switch: ON
Voltage between terminal No. 2 and earth.

OK: 4.75 - 5.25 V

Q. Is the check result normal?

	Go to Step 6 .

	Go to Step 3 .

STEP 3. Connector check: C-109 BMU connector

Q. Is the check result normal?

	Go to Step 4 .

	Repair.

STEP 4. Check harness between C-26 (terminal No. 2) main battery connector and C-109 (terminal No. 31) BMU connector

Check power supply line for open circuit, short circuit to earth.

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. Check main battery current sensor itself.

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

Q. Is the check result normal?

	Go to Step 7 .

	Replace the main battery.

STEP 7. 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 5 .

	Repair.