P0516

HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM: P0516-769, P0517-770: Battery Temperature Sensor Circuit Low
P0517-770 - Battery Temperature Sensor Circuit High

DESCRIPTION

- The battery thermometer sensor detects the auxiliary battery temperature. The resistance of the thermistor built into the battery thermometer sensor changes in accordance with changes in the auxiliary battery temperature. The lower the auxiliary battery temperature, the higher the battery thermometer sensor resistance. Conversely, the higher the temperature, the lower the resistance. The battery thermometer sensor is connected to the hybrid vehicle control ECU. A voltage of 5 V is supplied to the battery thermometer sensor from the THB terminal of the hybrid vehicle control ECU through its internal resistor R. This means that resistor R and the battery thermometer sensor are connected in series. The voltage at the THB terminal and the resistance value change in accordance with changes in the auxiliary battery temperature. Based on this signal, the hybrid vehicle control ECU reduces the charging current when the auxiliary battery temperature is high to protect the auxiliary battery.









WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
- Read the freeze frame data using the Techstream. In the freeze frame data, some information is recorded about the engine conditions at the moment a malfunction occurred. This information can be helpful when troubleshooting.
- The characteristics of the battery thermometer sensor resistance (reference values) are as follows.






PROCEDURE

1. CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR) P0343

NG -- CONNECT SECURELY
OK -- Continue to next step.

2. CHECK CONNECTOR CONNECTION CONDITION (BATTERY THERMOMETER SENSOR CONNECTOR)

(a) Check the connections of the battery thermometer sensor connector.





OK:

The connectors are connected securely and there are no contact problems.

NG -- CONNECT SECURELY
OK -- Continue to next step.

3. INSPECT BATTERY THERMOMETER SENSOR

(a) Disconnect connector M14 from the battery thermometer sensor.

(b) Measure the resistance according to the value(s) in the table below.





Standard Resistance:





Text in Illustration





(c) Connect the battery thermometer sensor connector.

NG -- REPLACE BATTERY THERMOMETER SENSOR
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - BATTERY THERMOMETER SENSOR)

(a) Disconnect connector M14 from the battery thermometer sensor.

(b) Disconnect connector A58 from the hybrid vehicle control ECU.





(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Turn the power switch on (IG).

(e) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





NOTICE:
Turning the power switch on (IG) with the hybrid vehicle control ECU connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

(f) Turn the power switch off.

(g) Connect the battery thermometer sensor connector.

(h) Connect the hybrid vehicle control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. CHECK FOR INTERMITTENT PROBLEMS

(a) Check for intermittent problems Check for Intermittent Problems.

NG -- REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA

OK -- REPLACE HYBRID VEHICLE CONTROL ECU Components