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Home >> Lexus >> 2024 >> RX 500h >> Repair and Diagnosis >> External Pages >> Different car >> Section 12 (Electronic A/T Shift Lever System - Diagnostic Codes (2 Of 2) & Circuit Tests) >> Electronic Shift Lever System >> DTC P1789-00: Lost Communication with Gear Shift Control Module "A" from "B" (Sub CPU) Missing Message [10/2022 - ] >> Description

DTC P1789-00: Lost Communication with Gear Shift Control Module "A" from "B" (Sub CPU) Missing Message [10/2022 - ]: Description

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The shift actuator ECU receives or sends a signal to or from the shift control ECU via CAN.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Warning Indicate DTC Output from Priority Note
P1789-00 Lost Communication with Gear Shift Control Module "A" from "B" (Sub CPU) Missing Message When the ignition switch is ON and the battery voltage is a certain value or more, a CAN communication malfunction with the shift control ECU is detected
(1 trip detection logic)
  • Shift control actuator assembly (shift actuator ECU)
  • Transmission floor shift assembly (shift control ECU)
  • Harness and connector
Does not come on Multi-information Display Error Message 
  • Displayed
Transmission A SAE: P1789