Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Detecting Vehicle Submersion (B2277)

DESCRIPTION

This DTC is stored when a malfunction in the water submersion detection circuit inside the certification ECU (smart key ECU assembly) is detected.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Note

B2277

Detecting Vehicle Submersion

Water submersion detected by the water submersion detection circuit inside the certification ECU (smart key ECU assembly). (1-trip detection logic*)

Certification ECU (Smart key ECU assembly)

  • Wait 300 seconds after connecting the cable to the negative (-) battery terminal.
  • *: Only detected while a malfunction is present.
Vehicle Condition and Fail-safe Function when Malfunction Detected

Vehicle Condition when Malfunction Detected

Fail-safe Function when Malfunction Detected

The engine switch cannot be turned off and the engine cannot be started.

-

Related Data List and Active Test Items

DTC No.

Data List and Active Test

B2277

-

CAUTION / NOTICE / HINT

NOTICE:

  • When using the Techstream with the engine switch off, connect the Techstream to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and the vehicle begins. Then select the vehicle type under manual mode and enter the following menus: Body Electrical / Smart Access. While using the Techstream, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the Techstream and the vehicle.
  • The smart access system with push-button start (for Start Function) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the smart access system with push-button start (for Start Function) after confirming that the communication systems are functioning properly.

    Click here

  • Before replacing the certification ECU (smart key ECU assembly), refer to the smart access system with push-button start (for Start Function) Precaution.

    Click here

  • After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

HINT:

  • Before proceeding with troubleshooting, check if there are any signs of water damage to the certification ECU (smart key ECU assembly). If there are any signs of water damage, replace the certification ECU (smart key ECU assembly) and take measures against the cause of the water damage.
  • When the cable is disconnected and reconnected to the negative (-) battery terminal, the power source mode returns to the state it was in before the cable was disconnected.

PROCEDURE

1.

CHECK WATER INTRUSION

(a) Check that the certification ECU (smart key ECU assembly), its ground area and wire harnesses have no signs of water intrusion.

Result

Proceed to

No sign of water intrusion found

A

Signs of water intrusion found

B

A

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

B

TAKE MEASURES FOR WATER INTRUSION AND REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

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