SMART KEY SYSTEM (for Start Function), Diagnostic DTC:B2274

DTC Code	DTC Name
B2274	ACC Monitor Malfunction

DESCRIPTION

This DTC is stored when a malfunction in the ACC output circuit is detected. The ACC output circuit is the circuit that goes from the ACC output terminal of the power management control ECU to the ACC relay.

Tech Tips

When the cable is disconnected and reconnected to the negative (-) auxiliary battery terminal, the power source mode returns to the state it was in before the cable was disconnected.

DTC Code	DTC Detection Condition	Trouble Area	DTC Output Confirmation Operation
B2274	Malfunction in the ACC relay circuit in the power management control ECU or in the external circuit (1-trip detection logic*). Tech Tips When the voltage at terminal ACCD is not at the standard, the system is determined to be malfunctioning.	AM2 fuse ACC relay (Instrument panel junction block assembly) Power management control ECU Wire harness or connector	Wait 10 seconds after turning the power switch on (ACC) or on (IG), and then wait another 10 seconds after turning the power 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 relay being stuck on, the ACC relay does not turn off even though the power switch is off. If there is a malfunction due to the relay being stuck off, the ACC relay does not turn on even though the power switch is on (ACC). Tech Tips The power switch can be turned on (IG) and the hybrid control system can be started.	-

WIRING DIAGRAM

INSPECTION PROCEDURE

Note

When using the Techstream with the power switch off, perform either of the following: 1) Turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and vehicle begins, or 2) connect the Techstream to the vehicle, select the vehicle type under manual mode, and then enter the following menus:

for Power Source Control: Body Electrical / Power Source Control / DTC.

for Smart Key: Body Electrical / Smart Key / DTC.
The smart key system (for Start Function) uses a multiplex communication system (LIN communication system) and the CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting Click here. Troubleshoot the smart key system (for Start Function) after confirming that the communication systems are functioning properly.
Inspect the fuses of circuits related to this system before performing the following inspection procedure.
After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.

Tech Tips

Related Data List and Active Test Items
DTC	Data List Item	Active Test Item
B2274	Power Source Control ACC Relay Monitor	-

PROCEDURE

CHECK HARNESS AND CONNECTOR (POWER SOURCE)

Text in Illustration
*a	Front view of wire harness connector (to Power Management Control ECU)

Disconnect the I3 and I4 connector from the power management control ECU.

Measure the voltage according to the value(s) in the table below.

Standard Voltage

Tester Connection	Condition	Specified Condition
I3-1 (AM22) - Body ground	Power switch off	11 to 14 V
I4-7 (AM21) - Body ground	Power switch off	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR IN CIRCUIT CONNECTED TO POWER SOURCE

CHECK HARNESS AND CONNECTOR (GROUND)

Text in Illustration
*a	Front view of wire harness connector (to Power Management Control ECU)

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
I3-5 (E01) - Body ground	Always	Below 1 Ω
I3-6 (E1) - Body ground	Always	Below 1 Ω
I4-4 (E12) - Body ground	Always	Below 1 Ω
I4-5 (E02) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

Disconnect the I4 connector from the power management control ECU.
Disconnect the 3B connector from the instrument panel junction block assembly.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
I4-1 (ACCD) - 3B-23	Always	Below 1 Ω
3B-7 - Body ground	Always	Below 1 Ω
I4-1 (ACCD) or 3B-23 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (ACC RELAY)

Remove the instrument panel junction block assembly Click here.

Text in Illustration
*a	Component without harness connected (Instrument Panel Junction Block Assembly)	-	-

Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly Click here.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
3E-1 - 3B-37 3E-1 - 3B-10	Auxiliary battery voltage not applied to terminals 3B-23 and 3B-7	10 kΩ or higher
3E-1 - 3B-37 3E-1 - 3B-10	Auxiliary battery voltage applied to terminals 3B-23 and 3B-7	Below 1 Ω

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

INSPECT POWER MANAGEMENT CONTROL ECU

Text in Illustration
*a	Component with harness connected (Power Management Control ECU)

Reconnect the I4 power management control ECU connector.

Measure the voltage according to the value(s) in the table below.

Standard Voltage

Tester Connection	Condition	Specified Condition
I4-1 (ACCD) - Body ground	Power switch off → Power switch on (ACC)	1 V or less → 8.5 V or higher

REPLACE POWER MANAGEMENT CONTROL ECU Click here

END (USE SIMULATION METHOD TO CHECK) Click here