DTC B1247: Tire Pressure Monitor Receiver Communication Stop [08/2022 - ]: Procedure

1. Using an oscilloscope, check the waveform.
   NOTE:

   With the connector connected, check from the backside of the connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *A	w/ Smart Key System
   *B	w/o Smart Key System
   *a	Component with harness connected (Tire Pressure Warning ECU and Receiver)
   *b	GND

   OK

   W/ SMART KEY SYSTEM
   
   

   Tester Connection	Tool Setting Range	Condition	Specified Condition
   R127-4 (RDA) - Body ground	5 V/DIV.5 ms./DIV.	Ignition switch ON	Waveform generation

   W/O SMART KEY SYSTEM
   
   

   Tester Connection	Tool Setting Range	Condition	Specified Condition
   R128-4 (RDA) - Body ground	5 V/DIV.5 ms./DIV.	Ignition switch ON	Waveform generation

   Result

   Result	Proceed to
   Waveform is as shown in the illustration. (Waveform alternates between 10.5 V or higher and 0.5 V or less)	A
   Waveform does not change from 10.5 V or higher	B
   Waveform does not change from 0.5 V or less	C

Result: 

A 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [10/2020 - ] 

Result: 

B 

REPLACE TIRE PRESSURE WARNING ECU AND RECEIVER. Refer to  REMOVAL [10/2020 - ] 

Result: 

C 

See step  2

1. Disconnect the R127 or R128 tire pressure warning ECU and receiver connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   W/ SMART KEY SYSTEM
   
   

   Tester Connection	Condition	Specified Condition
   R127-4 (RDA) - Body ground	Ignition switch ON	10.5 V or higher

   W/O SMART KEY SYSTEM
   
   

   Tester Connection	Condition	Specified Condition
   R128-4 (RDA) - Body ground	Ignition switch ON	10.5 V or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE TIRE PRESSURE WARNING ECU AND RECEIVER. Refer to  REMOVAL [10/2020 - ] 

Result: 

NG 

See step  3

1. Turn the ignition switch off.
2. Disconnect the K53 main body ECU (multiplex network body ECU) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   W/ SMART KEY SYSTEM
   
   

   Tester Connection	Condition	Specified Condition
   K53-10 (RDA) - R127-4 (RDA)	Always	Below 1 Ω
   K53-10 (RDA) or R127-4 (RDA) - Body ground	Always	10 kΩ or higher

   W/O SMART KEY SYSTEM
   
   

   Tester Connection	Condition	Specified Condition
   K53-10 (RDA) - R128-4 (RDA)	Always	Below 1 Ω
   K53-10 (RDA) or R128-4 (RDA) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [10/2020 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR