HYBRID CONTROL SYSTEM, Diagnostic DTC:P0516-769, P0517-770

DESCRIPTION

• The thermistor assembly 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 assembly is connected to the hybrid vehicle control ECU. A voltage of 5 V is supplied to the thermistor assembly from the THB terminal of the hybrid vehicle control ECU 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 hybrid vehicle control ECU reduces the charging current when the auxiliary battery temperature is high to protect the auxiliary battery.

  Tech Tips

  Characteristics of the thermistor assembly resistance (reference values) are as follows.

  Terminal	THB (with Connector Disconnected)	Resistance	Ambient Temperature
  THB - E2	4.5 to 5.5 V	3.00 to 3.73 kΩ	Approximately 10°C (50°F)
  		1.60 to 1.80 kΩ	Approximately 25°C (77°F)
  		0.80 to 1.00 kΩ	Approximately 40°C (104°F)

  

  *a	Resistance (kΩ)
  *b	Temperature (°C (°F))

WIRING DIAGRAM

*a	Thermistor Assembly
*b	Hybrid Vehicle Control ECU

CAUTION / NOTICE / HINT

PROCEDURE

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

   
   

   1. Check the connector connections and contact pressure of the relevant terminals for the hybrid vehicle control ECU connectors Click here.

      

      Text in Illustration

      *A

      for LHD

      *B

      for RHD

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

   
   

   NG

   CONNECT SECURELY

   OK

2. READ VALUE USING GTS (AUXILIARY BATT TEMPERATURE)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (IG).

   3. Enter the following menus: Powertrain / Hybrid Control / Data List / Auxiliary Batt Temperature.

   4. Read the Data List.

      Result
      Result Proceed to -40°C (-40°F) A 215°C (419°F) B Same as actual temperature C

   5. Turn the power switch off.

   
   

   B

   READ VALUE USING GTS (CHECK FOR SHORT) Click here

   C

   CHECK FOR INTERMITTENT PROBLEMS Click here

   A

3. READ VALUE USING GTS (CHECK FOR OPEN)

   
   

   1. 

      Disconnect the S17 thermistor assembly connector.

   2. 

      Connect terminals 2 (THB) and 1 (E2) of vehicle side connector S17 of the thermistor assembly.

   3. Connect the GTS to the DLC3.

   4. Turn the power switch on (IG).

   5. Enter the following menus: Powertrain / Hybrid Control / Data List / Auxiliary Batt Temperature.

   6. Read the Data List.

      Result
      Tester Display Condition Specified Condition Auxiliary Batt Temperature Terminals THB and E2 connected. Power switch on (IG) 215°C (419°F)

      Text in Illustration

      *a	Front view of wire harness connector (to Thermistor Assembly)

   7. Turn the power switch off.

   8. Reconnect the S17 thermistor assembly connector.

   
   

   OK

   REPLACE THERMISTOR ASSEMBLY

   NG

4. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - THERMISTOR ASSEMBLY)

   
   
   1. 

      Text in Illustration

      *a	Component with harness connected (Hybrid Vehicle Control ECU)

      Connect terminals 20 (THB) and 21 (ETHB) of connector L6 of the hybrid vehicle control ECU.

   2. Connect the GTS to the DLC3.

   3. Turn the power switch on (IG).

   4. Enter the following menus: Powertrain / Hybrid Control / Data List / Auxiliary Batt Temperature.

   5. Read the Data List.

      Result
      Tester Display Condition Specified Condition Auxiliary Batt Temperature Terminals THB and ETHB connected. Power switch on (IG) 215°C (419°F)

   6. Turn the power switch off.

   
   

   OK

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   NG

   REPLACE HYBRID VEHICLE CONTROL ECU Click here

5. READ VALUE USING GTS (CHECK FOR SHORT)

   
   

   1. 

      Disconnect the S17 thermistor assembly connector.

   2. Connect the GTS to the DLC3.

   3. Turn the power switch on (IG).

   4. Enter the following menus: Powertrain / Hybrid Control / Data List / Auxiliary Batt Temperature.

   5. Read the Data List.

      Result
      Tester Display Condition Specified Condition Auxiliary Batt Temperature Power switch on (IG) -40°C (-40°F)

   6. Turn the power switch off.

   7. Reconnect the S17 thermistor assembly connector.

   
   

   OK

   REPLACE THERMISTOR ASSEMBLY

   NG

6. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - THERMISTOR ASSEMBLY)

   
   

   1. Disconnect the S17 thermistor assembly connector.

   2. 

      Text in Illustration

      *a	Front view of wire harness connector (to Thermistor Assembly)
      *b	Rear view of wire harness connector (to Hybrid Vehicle Control ECU)

      Disconnect the L5 hybrid vehicle control ECU connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition L5-20 (THB) - S17-2 (THB) Power switch off Below 1 Ω L5-21 (ETHB) - S17-1 (E2) Power switch off Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition L5-20 (THB) or S17-2 (THB) - Body ground and other terminals Power switch off 10 kΩ or higher L5-21 (ETHB) or S17-1 (E2) - Body ground and other terminals Power switch off 10 kΩ or higher

   4. Reconnect the S17 thermistor assembly connector.

   5. Reconnect the L5 hybrid vehicle control ECU connector.

   
   

   OK

   REPLACE HYBRID VEHICLE CONTROL ECU Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR