P0516-769, P0517-770

DTC Code	DTC Name
P0516-769	Battery Temperature Sensor Circuit Low
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 higher the thermistor resistance. Conversely, the higher 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.

*a Resistance (kΩ)

*b Temperature (°C (°F))

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

DTC No.	INF Code	DTC Detection Condition	Trouble Area
P0516	769	Malfunction in the auxiliary battery temperature sensor circuit (short to GND)	Battery (Battery temperature sensor) Wire harness or connector Hybrid vehicle control ECU
P0517	770	Malfunction in the auxiliary battery temperature sensor circuit (open or short to +B)

WIRING DIAGRAM


*a	Hybrid Vehicle Control ECU
*b	Auxiliary Battery (Battery Temperature Sensor)

CAUTION / NOTICE / HINT

Tech Tips

Read the freeze frame data using the intelligent tester. 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.

Terminal	THB (with connector disconnected)	Resistance	Ambient Temperature
THB - E2	4.5 to 5.5 V	5.0 to 5.3 kΩ	Approximately 0°C (32°F)
2.3 to 2.5 kΩ	Approximately 20°C (68°F)
1.1 to 1.3 kΩ	Approximately 40°C (104°F)

Terminal

THB

(with connector disconnected)

Resistance

Ambient Temperature

THB - E2

4.5 to 5.5 V

5.0 to 5.3 kΩ

Approximately 0°C (32°F)

2.3 to 2.5 kΩ

Approximately 20°C (68°F)

1.1 to 1.3 kΩ

Approximately 40°C (104°F)

PROCEDURE

CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)
1. Check the connections of the hybrid vehicle control ECU connectors.
  
  OK
  
  The connectors are connected securely and there are no contact problems.
NG
CONNECT SECURELY

OK
CHECK CONNECTOR CONNECTION CONDITION (BATTERY TEMPERATURE SENSOR CONNECTOR)
1. Check the connection of the battery temperature sensor connector.
  
  OK
  
  The connector is connected securely and there are no contact problems.
NG
CONNECT SECURELY

OK

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

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

INSPECT BATTERY (BATTERY TEMPERATURE SENSOR)

Disconnect the battery (battery temperature sensor) connector.


*1	Component without harness connected: (Battery Temperature Sensor)

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

Standard resistance

Tester Connection	Condition	Specified Condition
S76-2 (THB) - S76-1 (E2)	0°C (32° F)	5.0 to 5.3 kΩ
	20°C (68° F)	2.3 to 2.5 kΩ
	40°C (104° F)	1.1 to 1.3 kΩ

Tech Tips

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

NG

REPLACE BATTERY

OK

CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - BATTERY TEMPERATURE SENSOR)


*1	Front view of wire harness connector: (to Battery Temperature Sensor)
*2	Rear view of wire harness connector: (to Hybrid Vehicle Control ECU)

Disconnect connectors A77 and A76 from the hybrid vehicle control ECU.

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

Standard resistance (Check for open)

Tester Connection	Switch Condition	Specified Condition
A77-30 (THB) - S76-2 (THB)	Power switch off	Below 1 Ω
A76-5 (E2) - S76-1 (E2)	Power switch off	Below 1 Ω

Standard resistance (Check for short)

Tester Connection	Switch Condition	Specified Condition
A77-30 (THB) or S76-2 (THB) - Body ground and other terminals	Power switch off	10 kΩ or higher
A76-5 (E2) or S76-1 (E2) - Body ground and other terminals	Power switch off	10 kΩ or higher

Turn the power switch on (IG).

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

Standard voltage

Tester Connection	Switch Condition	Specified Condition
A77-30 (THB) or S76-2 (THB) - Body ground	Power switch on (IG)	Below 1 V

Note

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

OK

REPLACE HYBRID VEHICLE CONTROL ECU Click here

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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