P0517

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

DESCRIPTION

- The thermistor assembly (battery temperature sensor) detects the auxiliary battery temperature. The resistance of the thermistor assembly built into the thermistor changes in accordance with changes in the auxiliary battery temperature. The lower the auxiliary battery temperature, the higher the thermistor assembly resistance. Conversely, the higher the temperature, the lower the resistance. The thermistor is connected to the power management control ECU (HV CPU). A voltage of 5 V is supplied to the thermistor assembly from the THB terminal of the power management control ECU (HV CPU) through its internal resistor R. This means that resistor R and the thermistor assembly 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 power management control ECU (HV CPU) 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.
- Characteristics of the thermistor resistance (reference values) are as follows.






PROCEDURE

1. CHECK CONNECTOR CONNECTION CONDITION (POWER MANAGEMENT CONTROL ECU CONNECTOR) P0340

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

2. CHECK CONNECTOR CONNECTION CONDITION (THERMISTOR ASSEMBLY CONNECTOR)

(a) Check the connection of the thermistor assembly connector.





OK:

The connector is connected securely and there are no contact problems.

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

3. CHECK THERMISTOR ASSEMBLY

(a) Disconnect connector P61 from the thermistor assembly.

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





Standard Resistance:





Text in Illustration





(c) Connect the thermistor assembly connector.

NG -- REPLACE THERMISTOR ASSEMBLY
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - THERMISTOR ASSEMBLY)

(a) Disconnect connector P61 from the thermistor assembly.

(b) Disconnect connector F97 from the power management 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):





Text in Illustration





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

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

Standard Voltage:





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

(f) Turn the power switch off.

(g) Connect the thermistor assembly connector.

(h) Connect the power management control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE POWER MANAGEMENT CONTROL ECU Components