P0517-770

L110 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0516-769: Battery Temperature Sensor Circuit Low

DTC P0516-769 - Battery Temperature Sensor Circuit Low

DTC P0517-770 - Battery Temperature Sensor Circuit High

DESCRIPTION
- The auxiliary battery temperature sensor detects the auxiliary battery temperature. The resistance of the thermistor built into the auxiliary battery temperature sensor changes in accordance with changes in the auxiliary battery temperature. The lower the auxiliary battery temperature, the more the thermistor resistance. Conversely, the more the temperature, the lower the resistance. The auxiliary battery temperature sensor is connected to the hybrid vehicle control ECU. A voltage of 5 V is supplied to the auxiliary battery temperature sensor from the THB terminal of the hybrid vehicle control ECU through its internal resistor R. This means that resistor R and the auxiliary battery temperature 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
CAUTION:
- Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
- After disconnecting the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting, check the voltage at the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.
HINT:
- Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.
- Read freeze frame data using the Techstream. In the freeze frame data, some information about the engine conditions at the moment a malfunction occurred is recorded. This information can be helpful when troubleshooting.
- Characteristics of the thermistor resistance (reference value) are as follows.






PROCEDURE

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





(a) Check the connections of all hybrid vehicle control ECU connectors.
Result:
The connectors are connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
2. CHECK CONNECTOR CONNECTION CONDITION (BATTERY TEMPERATURE SENSOR CONNECTOR)
(a) Check the connection of battery temperature sensor connector.
Result:
The connector is connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
3. INSPECT BATTERY (BATTERY TEMPERATURE SENSOR)
(a) Disconnect connector X4 from the battery temperature sensor.





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





HINT: The battery temperature sensor is not available separately. If it requires replacement, replace the battery.

NG -- REPLACE BATTERY
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (HV CONTROL ECU - BATTERY TEMPERATURE SENSOR)





(a) Disconnect connector A54 from the hybrid vehicle control ECU.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):






Standard resistance (Check for short):





(c) Turn the power switch on (IG).
(d) Measure the voltage according to the value(s) in the table below.
Standard voltage (+B short):





NOTE: 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.

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