DTC B2274: ACC Monitor Malfunction [08/2019 - ]: Description

WARNING: This page is about a different car, the 2021 Toyota Tundra and 2020 Toyota Tundra. However, it is still accessible from the selected car via links, so may be relevant.

This DTC is stored when a malfunction in the ACC output circuit is detected. The ACC output circuit is the circuit between terminal ACCD of the certification ECU (smart key ECU assembly) and the ACC relay.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B2274	ACC Monitor Malfunction	The ACC relay circuit of the certification ECU (smart key ECU assembly) is malfunctioning. (1-trip detection logic*) HINT: When the voltage at terminal ACCD is not at the standard, the system is determined to be malfunctioning.	Driver side junction block assembly Certification ECU (smart key ECU assembly) Harness or connector	DTC Output Confirmation Operation: Wait 10 seconds after turning the engine switch on (ACC) or on (IG), and then wait another 10 seconds after turning the engine switch off.

*: 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
If there is a malfunction due to the ACC relay being stuck on, the ACC relay does not turn off even though the engine switch is off. If there is a malfunction due to the ACC relay being stuck off, the ACC relay does not turn on even though the engine switch is on (ACC). HINT: The engine switch can be turned on (IG) and the engine can be started.	-

RELATED DATA LIST AND ACTIVE TEST ITEMS

DTC No.	Data List and Active Test
B2274	Power Source Control ACC Relay Monitor