Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Diagnostic Trouble Code Chart

DIAGNOSTIC TROUBLE CODE CHART

Wiper and Washer System

DTC No.

Detection Item

DTC Detection Condition

Link

B1245

Lost Communication with Wiper ECU LIN

When the battery voltage is 9.5 V or more, a communication malfunction between the main body ECU (multiplex network body ECU) and windshield wiper motor and link assembly (wiper ECU) is detected for 10 seconds or more

B1278

Lost Communication with Combination Switch ECU

When the battery voltage is 9.5 V or more, a communication malfunction between the main body ECU (multiplex network body ECU) and windshield wiper switch assembly is detected for 10 seconds or more.

B1279

Lost Communication with Humidity/Rain Sensor LIN

When the battery voltage is 9.5 V or more, a communication malfunction between the main body ECU (multiplex network body ECU) and rain sensor is detected for 10 seconds or more.

B1370

ECU Malfunction

When the battery voltage is 9.5 V or more, a malfunction is detected for 10 seconds or more during the wiper ECU self-check.

B1372

Wiper Switch Signal Mismatch between LIN and Line

When the battery voltage is 9.5 V or more, the operation signals sent via LIN communication and direct line do not match for 10 seconds or more.

B1373

Lost Communication with Wiper System LIN BUS

When the battery voltage is 9.5 V or more, a malfunction in the communication or LIN communication line between the main body ECU (multiplex network body ECU) and components of the wiper system occurs for 7 seconds or more 3 times consecutively.

B1400

Rain Sensor Malfunction

  • When the battery voltage is 9.5 V or more, the rain sensor temperature is abnormal for 10 seconds or more.
  • When the battery voltage is 9.5 V or more, the output of the LED built into the rain sensor is abnormal for 2 seconds or more.

    Data List / Active Test
    DATA LIST / ACTIVE TEST DATA LIST NOTICE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a pa ...

    Lost Communication with Wiper ECU LIN (B1245)
    DESCRIPTION The main body ECU (multiplex network body ECU) and windshield wiper motor and link assembly communicate via LIN communication. The main body ECU (multiplex network body ECU) stores this DT ...

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