Toyota Corolla Cross Owners & Service Manuals

Toyota Corolla Cross: Antenna Coil Open / Short (B2784)

Toyota Corolla Cross (2022-2024) Service Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Immobiliser System (w/o Smart Key System) / Antenna Coil Open / Short (B2784)

DESCRIPTION

When an open or short circuit is detected in the antenna coil built into the transponder key coil, the transponder key ECU assembly stores this DTC.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Note

B2784

Antenna Coil Open / Short

The antenna coil in the transponder key coil is open/shorted.
  • Wire harness or connector
  • Transponder key coil
  • Transponder key ECU assembly
DTC Output Confirmation Operation:
  • Insert the door control transmitter assembly into the ignition key cylinder.
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

B2784

Antenna Coil Status

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • If the transponder key ECU 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 CONNECTION OF CONNECTOR

(a) Check that the connector is properly connected to the transponder key coil.

NEXT

2.

CLEAR DTC

(a) Clear the DTCs.

Body Electrical > Immobiliser > Clear DTCs
NEXT

3.

CHECK FOR DTC

(a) Perform "DTC Output Confirmation Operation" procedure.

(b) Check for DTCs.

Body Electrical > Immobiliser > Trouble Codes

OK:

DTC B2784 is not output.

Result

Proceed to

B2784 is not output

A

B2784 is output

B
A

END (CONNECTOR WAS NOT CONNECTED PROPERLY)
B

4.

CHECK TRANSPONDER KEY COIL (OUTPUT)

(a) Disconnect the transponder key coil connector.

(b) Using an oscilloscope, check the waveform.

*a

Front view of wire harness connector

(to Transponder Key Coil)

*b

Waveform 1

*c

Waveform 2

-

-
OK

Tester Connection

Condition

Tool Setting

Specified Condition

I64-1 (ANT1) - Body ground

Within 3 seconds of inserting door control transmitter assembly into ignition key cylinder

20 V/DIV., 2 s./DIV.

Pulse generation

(See waveform 1)

I64-5 (ANT2) - Body ground

Within 3 seconds of inserting door control transmitter assembly into ignition key cylinder

20 V/DIV., 2 s./DIV.

Pulse generation

(See waveform 2)

OK:

Waveform is similar to that shown in the illustration.

OK

REPLACE TRANSPONDER KEY COIL

NG

5.

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

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

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

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
OK

REPLACE TRANSPONDER KEY ECU ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

    READ NEXT:

     Transponder Chip Malfunction (B2793,B2797)

    DESCRIPTION DTC B2793 is stored when a malfunction is found in the door control transmitter assembly during key ID code registration or a key ID code is not registered normally. Replace the door

     Unmatched Encryption Code (B2794)

    DESCRIPTION This DTC is stored when a door control transmitter assembly with an incomplete key ID code is inserted into the ignition key cylinder. DTC No. Detection Item DTC Detection Con

     Unmatched Key Code (B2795)

    DESCRIPTION This DTC is stored when a door control transmitter assembly with a different vehicle serial number is inserted into the ignition key cylinder. DTC No. Detection Item DTC Detec

    SEE MORE:

     Inspection

    INSPECTION PROCEDURE 1. INSPECT SHIFT LOCK CONTROL ECU HINT: If the results of the following inspections are as specified but a malfunction has occurred, replace the shift lock control unit assembly. (a) Inspect wire harness: (1) Disconnect the shift lock control ECU connector.

     Engine/Power Switch Signal Compare Failure (B227862)

    DESCRIPTION This DTC is stored when the SSW1 contact signal, SSW2 contact signal and SSW3 contact signal, which are detected when the power switch is operated, do not match. DTC No. Detection Item DTC Detection Condition Trouble Area Note B227862 Engine/Power Switch Sig

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