THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): B2779; Engine Starter Communication Malfunction; 2019 - 2024 MY RAV4 [11/2018 - ]

Last Modified: 01-30-2024	6.11:8.1.0	Doc ID: RM100000001G220
Model Year Start: 2019	Model: RAV4	Prod Date Range: [11/2018 - ]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): B2779; Engine Starter Communication Malfunction; 2019 - 2024 MY RAV4 [11/2018 - ]

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.

If communication between the remote engine start ECU and the certification ECU (smart key ECU assembly) is established and the remote engine start is operated, this DTC and the corresponding history DTC will be cleared.

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	When the remote engine start is operated to try to turn the power source on, or start the engine, the remote start function tries to communicate with the certification ECU (smart key ECU assembly), but communication fails. (1 trip detection logic*)	CAN communication system Remote start ECU (genuine part) Main body ECU (multiplex network body ECU) Certification ECU (smart key ECU assembly)	DTC output confirmation operation: Always

*: Only detected 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
The engine cannot be started with a remote start operation	The engine cannot be started with a 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 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 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
Before replacing the certification ECU (smart key ECU assembly) or main body ECU (multiplex network body ECU), refer to the Registration.
Click here
After repair, 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.

NG

GO TO CAN COMMUNICATION SYSTEM (DIAGNOSTIC TROUBLE CODE CHART)

OK

2.	READ VALUE USING TECHSTREAM (WIRELESS C CODE)

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(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 starter 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

B

A

3.	REGISTER REMOTE ENGINE STARTER ID

(a) Register the remote engine starter ID.

HINT:

Refer to Registration.

Click here

NEXT

4.	CHECK REMOTE ENGINE STARTER FUNCTION

(a) Check the remote engine starter function.

OK:

Remote engine starter functions operate normally.

OK

END (REMOTE ENGINE STARTER ID WAS NOT REGISTERED)

NG

5.	CHECK REMOTE ENGINE STARTER ECU

(a) Temporarily replace the remote engine starter ECU with a new one.

(b) Register the remote engine starter ID.

HINT:

Refer to Registration.

Click here

(c) Check the remote engine starter function.

OK:

Remote engine starter functions operate normally.

OK

END (REMOTE ENGINE STARTER ECU WAS DEFECTIVE)

NG

6.	CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

(a) Replace the main body ECU (multiplex network body ECU) with a new one.

Click here

(b) Check the remote engine starter function.

OK:

Remote engine starter functions operate normally.

OK

END (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) WAS DEFECTIVE)

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)