Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001H8D9
Model Year Start: 2020 Model: Corolla Prod Date Range: [01/2019 - 09/2022]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): B2274; ACC Monitor Malfunction; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

DTC

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 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.
  • Instrument panel junction block assembly
  • Certification ECU (smart key ECU assembly)
  • Wire harness or connector

DTC Output Confirmation Operation:

  • 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 ACC 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 ACC relay being stuck off, the ACC relay does not turn on even though the power switch is on (ACC).

HINT:

The power switch can be turned on (IG) and the hybrid control system can be started.

-

Related Data List and Active Test Items

DTC No.

Data List and Active Test

B2274

Power Source Control

  • ACC Relay Monitor

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • When using the Techstream with the power 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 Key. 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 key system (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 key system (for Start Function) after confirming that the communication systems are functioning properly.

    Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): HOW TO PROCEED WITH TROUBLESHOOTING

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • Before replacing the certification ECU (smart key ECU assembly), refer to Registration.

    Click here 2020 MY Corolla Corolla HV [01/2019 - 04/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION

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

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BODY GROUND)

(a) Disconnect the I1 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the 4D, 4E and 4F instrument panel junction block assembly connectors.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I1-16 (ACCD) - 4E-30

Always

Below 1 Ω

4F-3 - Body ground

Always

Below 1 Ω

I1-16 (ACCD) or 4E-30 - Other terminals and body ground

Always

10 kΩ or higher

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

4D-1 - Body ground

Power switch off

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

2.

CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (ACC RELAY)

(a) Remove the instrument panel junction block assembly.

Click here 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL

(b) Connect all of the instrument panel junction block assembly connectors.

(c) Connect the I1 certification ECU (smart key ECU assembly) connector.

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

*a

Component with harness connected

(Instrument Panel Junction Block Assembly)

-

-

Standard Voltage:

Tester Connection

Condition

Specified Condition

4A-26 - Body ground

Power switch on (ACC)

11 to 14 V
NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL

OK

3.

CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

I1-16 (ACCD) - Body ground

Power switch off → Power switch on (ACC)

1 V or less → 8.5 V or higher

*a

Component with harness connected

(Certification ECU (Smart Key ECU Assembly))
OK

END (TEMPORARY CONNECTION FAILURE IS SUSPECTED)

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL