DTC B2301-87: Lost Communication with Gear Shift Control Module "A" (Line) Missing Message [08/2023 - ]: Description

WARNING: This page is about a different car, the 2025 Lexus RX 350, 2024 Lexus RX 350, and 2023 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.

As backup control for when an auxiliary battery power source malfunction occurs, communication is performed with the transmission floor shift assembly (shift control ECU).

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	DTC Output from	Priority
B2301-87	Lost Communication with Gear Shift Control Module "A" (Line) Missing Message	The PWM communication status at the BR terminal is being monitored and the signal is outside of the specified value or the PWM duty cycle of the signal is 0% or 100% for 1 second or more	Integrated capacitor (integration control supply) Transmission floor shift assembly (shift control ECU) Harness or connector	User informed: Yes	Sub Battery System	A

CHECK FOR DTCs
1. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
2. Turn the ignition switch off and wait 6 minutes or more. (A)
3. Turn the ignition switch to ON. (B)
4. Turn the GTS on. (C)
5. Wait for 10 seconds or more. (D)
6. Read the DTCs. (E)
  HINT:
  - If a DTC is output, the system is malfunctioning.
  - If a DTC is not output, perform the following procedure.
7. Enter the following menus: Body Electrical / Sub Battery System / Utility / All Readiness. (F)
8. Enter the DTC to be checked. (G)
9. Check the DTC judgment result. (H)
  HINT:
  - If the judgment result is NORMAL, the system is normal.
  - If the judgment result is ABNORMAL, the system is malfunctioning.
  - If the judgment result is INCOMPLETE, perform steps (A) through (H) again.