THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): B2779; Engine Starter Communication Malfunction; 2020 - 2022 MY Corolla Corolla HV [01/2019

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM100000001H8DH
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): B2779; Engine Starter Communication Malfunction; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

DTC

B2779

Engine Starter Communication Malfunction

DESCRIPTION

If the remote engine start ECU does not respond to the certification ECU (smart key ECU assembly) or the remote engine start ID is not registered, this DTC is stored.

HINT:

Registration status of the remote engine start ECU ID can be checked using the "Wireless C Code" item in the Data List.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B2779	Engine Starter Communication Malfunction	One of the following conditions is met (1 trip detection logic*): A remote start communication error occurs. Response is not possible. Registration has not been performed.	CAN communication system Remote engine start ECU Certification ECU (smart key ECU assembly)	DTC output confirmation operation: A remote start operation is performed.

*: Only output while a malfunction is present.

Vehicle Condition and Fail-safe Operation when Malfunction Detected

Vehicle Condition when Malfunction Detected	Fail-safe Operation when Malfunction Detected
Hybrid control system does not start with remote start operation	Hybrid control system cannot be started by remote start operation only

Related Data List and Active Test

DTC No.	Data List and Active Test
B2779	Smart Key Wireless Starter Com ID Wireless C Code

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.
Before performing the inspection, check that DTC B1242 (wireless door lock control system) is not output.
Before replacing the certification ECU (smart key ECU assembly), refer to Registration.
Click here
After performing repairs, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE

1.	CHECK CAN COMMUNICATION SYSTEM

(a) Check for CAN communication system DTCs.

Click here

OK:

CAN communication DTCs are not output.

GO TO CAN COMMUNICATION SYSTEM (DIAGNOSTIC TROUBLE CODE CHART)

2.	READ VALUE USING TECHSTREAM (WIRELESS C CODE)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(d) Enter the following menus: Body Electrical / Smart Key / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Smart Key > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Wireless C Code

Registration status between remote engine start ECU and certification ECU (smart key ECU assembly)

No Regd or Regd

No Regd: Remote starter ID not registered to remote engine start ECU and certification ECU (smart key ECU assembly)

Regd: Remote starter ID registered to remote engine start ECU and certification ECU (smart key ECU assembly)

Problems may be caused by the following:

DTC B2779 is stored.
Remote engine start ECU registration has not been performed.
Malfunctions in the certification ECU (smart key ECU assembly) or remote engine start ECU.

Body Electrical > Smart Key > Data List

Tester Display
Wireless C Code

Result	Proceed to
"No Regd" is displayed on the Techstream	A
"Regd" is displayed on the Techstream	B

REPLACE REMOTE ENGINE START ECU

3.	REGISTER REMOTE ENGINE STARTER ID

(a) Register the remote engine starter ID.

4.	READ VALUE USING TECHSTREAM (WIRELESS C CODE)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(d) Enter the following menus: Body Electrical / Smart Key / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Smart Key > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Wireless C Code

Registration status between remote engine start ECU and certification ECU (smart key ECU assembly)

No Regd or Regd

No Regd: Remote starter ID not registered to remote engine start ECU and certification ECU (smart key ECU assembly)

Regd: Remote starter ID registered to remote engine start ECU and certification ECU (smart key ECU assembly)

Problems may be caused by the following:

DTC B2779 is stored.
Remote engine start ECU registration has not been performed.
Malfunctions in the certification ECU (smart key ECU assembly) or remote engine start ECU.

Body Electrical > Smart Key > Data List

Tester Display
Wireless C Code

Result	Proceed to
"Regd" is displayed on the Techstream	A
"No Regd" is displayed on the Techstream	B

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

5.	CHECK REMOTE ENGINE STARTER FUNCTION

(a) Check the remote engine starter function.

OK:

Remote engine starter functions operate normally.

USE SIMULATION METHOD TO CHECK

REPLACE REMOTE ENGINE START ECU