DTC B2357: Lost Communication with Wiper Module [12/2019 - 11/2023]: Procedure

1. Disconnect the A7 windshield wiper relay assembly connector.
2. Disconnect the H44 main body ECU (multiplex network body ECU) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A7-4 (MPX1) - H44-5 (CXP1)	Always	Below 1 Ω
   A7-4 (MPX1) or H44-5 (CXP1) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  2

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Check for voltage and pulses according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   H44-5 (CXP1) - Body ground	Ignition switch ON	Pulse generation
   	Less than approximately 100 seconds after ignition switch turned off
   	Approximately 100 seconds or more after ignition switch turned off	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

Result: 

OK 

See step  3

1. Perform the Active Test according to the display on the GTS.

   Body Electrical > Main Body > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Wiper Power Relay	Function to operate the IG1 WIP relay	OFF or ON	-

   Body Electrical > Main Body > Active Test 

   Tester Display
   Wiper Power Relay

   OK

   IG1 WIP relay operates normally.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  9

Result: 

OK 

See step  4

1. Disconnect the A6 windshield wiper relay assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A6-3 (E) - Body ground	Always	Below 1 Ω
   A7-5 (ES) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A6-8 (+B) - Body ground	Ignition switch ON	11 to 14 V
   	Less than approximately 60 seconds after ignition switch turned off	11 to 14 V
   	Approximately 60 seconds or more after ignition switch turned off	Below 1 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE WINDSHIELD WIPER RELAY ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

Result: 

NG 

See step  6

1. Inspect the WIPER relay.

   Refer to ON-VEHICLE INSPECTION [12/2019 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE WIPER RELAY 

Result: 

OK 

See step  7

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   5 (WIPER relay) - Body ground	Ignition switch off*1 Always*2	11 to 14 V

   1. *1: for HV Model
   2. *2: for Gasoline Model

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  8

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A6-8 (+B) - 3 (WIPER relay)	Always	Below 1 Ω
   A6-8 (+B) or 3 (WIPER relay) - 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 [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Inspect the WIPER relay.

   Refer to ON-VEHICLE INSPECTION [12/2019 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE WIPER RELAY 

Result: 

OK 

See step  10

1. Disconnect the H43 main body ECU (multiplex network body ECU) connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   2 (WIPER relay) - H43-21 (WPS)	Always	Below 1 Ω
   2 (WIPER relay) or H43-21 (WPS) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  11

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1 (WIPER relay) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR