Code No. P0515: Battery Temperature Sensor System <Euro5b>




OPERATION



  • A power voltage of 5 V is applied to the battery temperature sensor output terminal (terminal No. 2) from the engine-ECU (terminal No. 39).
  • The power voltage is earthed to the engine-ECU (terminal No. 155) from the battery temperature sensor (terminal No. 3).

FUNCTION



  • The battery temperature sensor converts the battery temperature into a voltage and inputs the signal to the engine-ECU.
  • In response to the signal, the engine-ECU controls charging and discharging.
  • The battery temperature sensor is a kind of resistor, which has characteristics to reduce its resistance as the battery temperature rises. Therefore, the sensor output voltage varies with the battery temperature, and becomes lower as the battery temperature rises.

TROUBLE JUDGMENT


Check Condition
  • Battery positive voltage is 8 - 16 V.
  • 2 seconds later after the ignition switch has been in "ON" position or the engine has started up.
Judgment Criterion
  • The battery temperature sensor output voltage is more than 4.88 V.


  • The battery temperature sensor output voltage is less than 0.99 V.

PROBABLE CAUSES



  • Failed battery temperature sensor
  • Open/short circuit or harness damage in battery temperature sensor circuit or loose connector contact
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

  • Item No. 402: Battery temperature sensor
OK: At ambient temperature (atmospheric temperature) of battery temperature sensor, or equivalent

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 2.

STEP 2. Connector check: A-152 battery current sensor connector

Q. Is the check result normal?

Go to Step 3.

Repair or replace the connector.

STEP 3. Check battery temperature sensor itself.

  • Check battery temperature sensor itself (Refer to GROUP 54A - Battery - Inspection - Battery Current Sensor Check ).

Q. Is the check result normal?
Go to Step 4.
Replace the battery current sensor.

STEP 4. Perform voltage measurement at A-152 battery current sensor connector.


  • Disconnect connector and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 2 and earth.
OK: 4.5 - 4.9 V

Q. Is the check result normal?

Go to Step 8.

Go to Step 5.

STEP 5. Connector check: C-105 engine-ECU connector

Q. Is the check result normal?

Go to Step 6.

Repair or replace the connector.

STEP 6. Check harness between A-152 (terminal No. 2) battery current sensor connector and C-105 (terminal No. 39) engine-ECU connector.



  • Check output line for open/short circuit.

Q. Is the check result normal?

Go to Step 7.

Repair the damaged harness wire.

STEP 7. M.U.T.-III data list

  • Item No. 402: Battery temperature sensor
OK: At ambient temperature (atmospheric temperature) of battery temperature sensor, or equivalent

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - Precautions Before Service - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ). After registering the injector identification code, carry out the forcible DPF regeneration. (Refer to GROUP 17 - Emission Control - Diesel Particulate Filter (DPF) System - Forcible DPF Regeneration ).

STEP 8. Perform resistance measurement at A-152 battery current sensor connector.


  • Disconnect connector and measure at harness side.
  • Resistance between terminal No. 3 and earth.
OK: Continuity (2 Ω or less)

Q. Is the check result normal?

Go to Step 11.

Go to Step 9.

STEP 9. Connector check: C-103 engine-ECU connector

Q. Is the check result normal?

Go to Step 10.

Repair or replace the connector.

STEP 10. Check harness between A-152 (terminal No. 3) battery current sensor connector and C-103 (terminal No. 155) engine-ECU connector.



  • Check earthing line for open circuit and damage.

Q. Is the check result normal?

Go to Step 7.

Repair the damaged harness wire.

STEP 11. Connector check: C-105 engine-ECU connector

Q. Is the check result normal?

Go to Step 12.

Repair or replace the connector.

STEP 12. Check harness between A-152 (terminal No. 2) battery current sensor connector and C-105 (terminal No. 39) engine-ECU connector.



  • Check output line for damage.

Q. Is the check result normal?

Go to Step 7.

Repair the damaged harness wire.