Toyota Tacoma manuals

Toyota Tacoma 2015-2018 Service Manual: 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.

DTC Detection Condition

Trouble Area

DTC Output Confirmation Operation

B2784

The antenna coil in the transponder key coil is open/shorted.

  • Wire harness or connector
  • Transponder key coil
  • Transponder key ECU assembly

Insert the door control transmitter assembly into the ignition key cylinder, turn the ignition switch from off to ON and wait at least 20 seconds.

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

CAUTION / NOTICE / HINT

NOTICE:

  • If the transponder key ECU assembly is replaced, refer to Registration (See page After repair, confirm that no DTCs are output by performing "DTC Output ).
  • After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE

1.

CLEAR DTC

(a) Clear the DTCs (See page ).

NEXT

2.

CHECK FOR DTC

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

(b) Check for DTCs (See page OK: ).

OK:

DTC B2784 is not output.

Result

Result

Proceed to

DTC B2784 is output

A

DTC B2784 is not output

B

B

USE SIMULATION METHOD TO CHECK

A

3.

CHECK CONNECTION OF CONNECTOR

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

NEXT

4.

CLEAR DTC

(a) Clear the DTCs (See page ).

NEXT

5.

CHECK FOR DTC

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

(b) Check for DTCs. (See page OK: ).

OK:

DTC B2784 is not output.

Result

Result

Proceed to

DTC B2784 is not output

A

DTC B2784 is output

B

A

END (CONNECTOR WAS NOT CONNECTED PROPERLY)

B

6.

CHECK TRANSPONDER KEY COIL (OUTPUT)

(a) Using an oscilloscope, check the waveform.

Text in Illustration

*a

Component with harness connected

(Transponder Key Coil)

*b

Waveform 1

*c

Waveform 2

-

-

Measurement Condition:

Tester Connection

Condition

Tool Setting

Specified Condition

T9-1 (ANT1) - Body ground

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

2 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform 1)

T9-5 (ANT2) - Body ground

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

2 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform 2)

OK:

Waveform is similar to that shown in the illustration.

Result

Result

Proceed to

NG

A

OK

B

B

REPLACE TRANSPONDER KEY COIL

A

7.

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

(a) Disconnect the T10 transponder key ECU assembly connector.

(b) Disconnect the T9 transponder key coil connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

T10-4 (ANT1) - T9-1 (ANT1)

Always

Below 1 Ω

T10-15 (ANT2) - T9-5 (ANT2)

Always

Below 1 Ω

T10-4 (ANT1) or T9-1 (ANT1) - Body ground

Always

10 kΩ or higher

T10-15 (ANT2) or T9-5 (ANT2) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

8.

REPLACE TRANSPONDER KEY ECU ASSEMBLY

(a) Replace the transponder key ECU assembly with a new one (See page NOTICE: ).

NOTICE:

Key ID code registration is necessary when replacing the transponder key ECU assembly, refer to Registration (See page ).

NEXT

9.

CLEAR DTC

(a) Clear the DTCs (See page ).

NEXT

10.

CHECK FOR DTC

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

(b) Check for DTCs (See page OK: ).

OK:

DTC B2784 is not output.

Result

Result

Proceed to

DTC B2784 is not output

A

DTC B2784 is output

B

A

END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)

B

REPLACE TRANSPONDER KEY COIL

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