DTC P0AAE-123: Hybrid Battery Pack Air Temperature Sensor "A" Circuit Low; DTC P0AAF-123: Hybrid Battery Pack Air Temperature Sensor "A" Circuit High: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
4. Check if DTCs are output.

   Result

   DTC P0A1F-123 is output.

YES → GO TO INSPECTION PROCEDURE RELEVANT TO OUTPUT DTC 

NO: Go to next step 

1. Remove the service plug grip. Refer to REMOVAL
2. Remove the HV relay assembly. Refer to REMOVAL
3. Check the connection of connector o1 of the battery smart unit.
   Fig 1: Identifying o1 Connector Location

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

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

   HINT: 

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

NG → CONNECT SECURELY 

OK: Go to next step 

1. Remove the battery smart unit. Refer to REMOVAL .
2. Disconnect connector o1 from the battery smart unit.
3. Measure the resistance according to the value(s) in the table below.
   Fig 2: Identifying Battery Smart Unit O1 Connector Terminal Identification

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance

   Tester Connection	Specified Condition
   TC0 (o1-1) - GC0 (o1-11)	26.7 to 27.9 kΩ at 0°C (32°F)
   TC0 (o1-1) - GC0 (o1-11)	9.9 to 10.1 kΩ at 25°C (77°F)
   TC0 (o1-1) - GC0 (o1-11)	5.7 to 6.0 kΩ at 40°C (104°F)

NG → See step   5 

OK: Go to next step 

1. Disconnect connector o1 from the battery smart unit.
2. Disconnect connector n2 from the battery smart unit.
3. Measure the resistance according to the value(s) in the table below.
   Fig 3: Identifying Battery Smart Unit O1 And N2 Connector End View

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance (Check for short)

   Tester Connection	Specified Condition
   TB0 (o1-7) - IGC1 (n2-1)	10 kΩ or higher
   GB0 (o1-17) - IGC1 (n2-1)	10 kΩ or higher
   TB1 (o1-6) - IGC1 (n2-1)	10 kΩ or higher
   GB1 (o1-16) - IGC1 (n2-1)	10 kΩ or higher
   TB2 (o1-5) - IGC1 (n2-1)	10 kΩ or higher
   GB2 (o1-15) - IGC1 (n2-1)	10 kΩ or higher
   TB3 (o1-4) - IGC1 (n2-1)	10 kΩ or higher
   GB3 (o1-14) - IGC1 (n2-1)	10 kΩ or higher
   TC0 (o1-1) - IGC1 (n2-1)	10 kΩ or higher
   GC0 (o1-11) - IGC1 (n2-1)	10 kΩ or higher
   TB0 (o1-7) - GND (n2-5)	10 kΩ or higher
   TB1 (o1-6) - GND (n2-5)	10 kΩ or higher
   TB2 (o1-5) - GND (n2-5)	10 kΩ or higher
   TB3 (o1-4) - GND (n2-5)	10 kΩ or higher
   TC0 (o1-1) - GND (n2-5)	10 kΩ or higher

NG → See step   5 

OK → See step   6