B2779

THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER SYSTEM (w/ Smart Key System): B2779: Engine Starter Communication Malfunction
B2779 - Engine Starter Communication Malfunction

DESCRIPTION

If the communication between the remote start ECU and certification ECU (smart key ECU assembly) cannot be performed even though a remote start operation is performed in an attempt to change the power source mode to on (IG) or start the engine, this DTC is stored.

When the remote start ECU does not respond to the certification ECU (smart key ECU assembly) or the remote start ID code is not registered*, this DTC is stored. When communication with the remote start ECU is established and a remote start operation is performed, this DTC is cleared and is not stored as a past DTC.

HINT
*: Check "Wireless C Code" in the Data List Smart Key System (for Entry Function).





* *: Only output while a malfunction is present.

Vehicle Condition and Fail-safe Operation when Malfunction Detected





Related Data List and Active Test





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* Before performing the inspection, check that DTC U0142 is not output.
* Before replacing the certification ECU (smart key ECU assembly), refer to Registration Engine Immobilizer System (w/ Smart Key System).
* After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.

HINT
In this repair manual, only the terminal numbers used for inspection between the main body ECU (multiplex network body ECU) and option connector are listed.

PROCEDURE

1. READ VALUE USING TECHSTREAM (REGISTRATION STATUS)

(a) Turn the engine switch off.

HINT
When using the Techstream with the engine switch off to troubleshoot: Connect the Techstream to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds until communication between the Techstream and vehicle begins.

(b) Using the Techstream, read the Data List Engine Immobilizer System (w/ Smart Key System).

Smart Key





OK:

"Regd" appears on screen.

Result





B -- CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - OPTION CONNECTOR)
A -- Continue to next step.

2. REGISTER REMOTE START ID

(a) Register the remote start ID.

NEXT -- Continue to next step.

3. CHECK REMOTE START

(a) Check that the engine can be started using the remote start operation.

OK:

Engine can be started using remote start operation.

NG -- CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - OPTION CONNECTOR)

OK -- END (REMOTE START ID IS NOT REGISTERED CORRECTLY)

4. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - OPTION CONNECTOR)

HINT
In this repair manual, only the terminal numbers used for inspection between the main body ECU (multiplex network body ECU) and option connector are listed.

(a) Disconnect the C56 main body ECU (multiplex network body ECU) connector.

(b) Disconnect the C54 option connector (to remote start ECU) connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. REPLACE REMOTE START ECU

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

(b) Register the remote start ID.

(c) Check that the engine can be started using the remote start operation.

OK:

Engine can be started using remote start operation.

NG -- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

OK -- END (REMOTE START ECU IS DEFECTIVE)

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

(a) Temporarily replace the main body ECU (multiplex network body ECU) with a new or normally functioning one Removal.

(b) Check that the engine can be started using the remote start operation.

OK:

Engine can be started using remote start operation.

NG -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Removal

OK -- END (MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] IS DEFECTIVE)