Toyota Corolla Cross: No Communication in Immobiliser System (B2796,B2798)

Toyota Corolla Cross (2022-2025) Service Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Immobiliser System (w/o Smart Key System) / No Communication in Immobiliser System (B2796,B2798)

DESCRIPTION

This DTC is stored when a door control transmitter assembly is inserted into the ignition key cylinder but no communication occurs between the door control transmitter assembly and transponder key ECU assembly.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B2796	No Communication in Immobiliser System	The key ID code cannot be transmitted to the transponder key ECU assembly (1 trip detection logic*).	Door control transmitter assembly Wire harness or connector	DTC Output Confirmation Operation: Insert the door control transmitter assembly into the ignition key cylinder.
B2798	Communication Malfunction No. 2	Key ID code identification cannot be completed within the specified time (1 trip detection logic*).	Door control transmitter assembly Wire harness or connector	DTC Output Confirmation Operation: Insert the door control transmitter assembly into the ignition key cylinder.

*: 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
Engine cannot be started	-

Related Data List and Active Test

DTC No.	Data List and Active Test
B2796	-
B2798	-

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

If the door control transmitter assembly is replaced, refer to Registration.
Click here
After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - TRANSPONDER KEY COIL)

(a) Disconnect the I67 transponder key ECU assembly connector.

(b) Disconnect the I64 transponder key coil connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
I67-2 (ANT1) - I64-1 (ANT1)	Always	Below 1 Ω
I67-3 (ANT2) - I64-5 (ANT2)	Always	Below 1 Ω
I67-2 (ANT1) or I64-1 (ANT1) - Other terminals and body ground	Always	10 kΩ or higher
I67-3 (ANT2) or I64-5 (ANT2) - Other terminals and body ground	Always	10 kΩ or higher

REPLACE DOOR CONTROL TRANSMITTER ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

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Toyota Corolla Cross: No Communication in Immobiliser System (B2796,B2798)

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