P0A9C

HYBRID BATTERY CONTROL: HYBRID BATTERY SYSTEM: P0A9C-123: Hybrid Battery Temperature Sensor "A"

DTC P0A9C-123 - Hybrid Battery Temperature Sensor "A"

DESCRIPTION

- The battery temperature sensors are provided at 4 locations on the bottom of the HV battery. The resistance of the thermistor, which is built into each battery temperature sensor, varies in accordance with changes in the HV battery temperature. The lower the battery temperature, the higher the thermistor resistance. Conversely, the higher the temperature, the lower the resistance. The battery smart unit uses the battery temperature sensors to detect the HV battery temperature, and sends the detected values to the hybrid vehicle control ECU. Based on these results, the hybrid vehicle control ECU controls the blower fan. (The blower fan starts when the HV battery temperature rises above a predetermined level.)

MONITOR DESCRIPTION

If the temperature indicated by the battery temperature sensor is lower than the standard level (open), or is higher than the standard level (short), the battery smart unit interprets this as a sensor malfunction. If the battery smart unit detects that HV battery temperature is out of a normal range or its value is abnormal, the hybrid vehicle control ECU will illuminate the MIL and set a DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

WIRING DIAGRAM

INSPECTION PROCEDURE
CAUTION:
- Before inspecting the high-voltage system, 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.
HINT: Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

PROCEDURE

1. CHECK DTC OUTPUT (DTC P0A1F-123 IS OUTPUT)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(d) Check if DTCs are output.
Result:
DTC P0A1F-123 is output.
YES -- GO TO INSPECTION PROCEDURE RELEVANT TO OUTPUT DTC
NO -- Continue to next step.
2. CHECK BATTERY TEMPERATURE SENSOR (BATTERY TEMPERATURE SENSOR 0 TO 3)
CAUTION:
Be sure to wear insulated gloves.
(a) Remove the HV battery assembly. Removal
(b) Visually check the installation of the battery temperature sensors (0 to 3) through the exhaust duct installation hole.

OK:
The battery temperature sensors (0 to 3) are securely installed.
NOTICE:
Do not poke the battery temperature sensors with a stick or other objects when checking. Doing so may damage the sensors.

NG -- REPLACE HV BATTERY
OK -- Continue to next step.
3. CHECK HV BATTERY (BATTERY TEMPERATURE SENSOR)
CAUTION:
Be sure to wear insulated gloves.

(a) For the malfunctioning battery temperature sensor(s), measure the resistance according to the value(s) in the table below.
Thermistor No.:

Standard resistance:

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

NG -- REPLACE HV BATTERY
OK -- REPLACE BATTERY SMART UNIT