Toyota Venza: Antenna Coil Open / Short (B2784)

Toyota Venza Service Manual / Theft Deterrent / Keyless Entry / Engine Immobiliser System(w/o Smart Key System) / Antenna Coil Open / Short (B2784)

DESCRIPTION

The transponder key coil is built into the transponder key amplifier and receives a key code signal from the transponder chip in the key. This signal is amplified by the amplifier, then it is output to the transponder key ECU assembly.

DTC No.	DTC Detection Condition	Trouble Area
B2784	Antenna coil is open/shorted.	Wire harness or connector Transponder key amplifier Transponder key ECU assembly

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

If the transponder key ECU assembly is replaced, register the key and ECU communication ID (See page ).

PROCEDURE

1.	READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Body Electrical / Immobiliser / Data List.

(e) Read the Data List according to the display on the Techstream.

Immobiliser (Transponder Key ECU Assembly)

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Antenna Coil Status	Transponder key amplifier coil condition/Normal or Fail	Normal: Antenna coil normal Fail: Antenna coil malfunctioning	-

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Antenna Coil Status

Transponder key amplifier coil condition/Normal or Fail

Normal: Antenna coil normal

Fail: Antenna coil malfunctioning

OK:

On the Techstream screen, the item displays Normal according to the chart above.

REPLACE TRANSPONDER KEY ECU ASSEMBLY

2.	CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)

(a) Disconnect the transponder key ECU assembly connector.

(b) Disconnect the transponder key amplifier connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
D22-4 (TXCT) - D21-5 (TXCT)	Always	Below 1 Ω
D22-5 (AGND) - D21-7 (AGND)	Always	Below 1 Ω
D22-14 (VC5) - D21-1 (VC5)	Always	Below 1 Ω
D22-15 (CODE) - D21-4 (CODE)	Always	Below 1 Ω
D22-4 (TXCT) - Body ground	Always	10 kΩ or higher
D22-5 (AGND) - Body ground	Always	10 kΩ or higher
D22-14 (VC5) - Body ground	Always	10 kΩ or higher
D22-15 (CODE) - Body ground	Always	10 kΩ or higher
D21-5 (TXCT) - Body ground	Always	10 kΩ or higher
D21-7 (AGND) - Body ground	Always	10 kΩ or higher
D21-1 (VC5) - Body ground	Always	10 kΩ or higher
D21-4 (CODE) - Body ground	Always	10 kΩ or higher

Text in Illustration

Front view of wire harness connector

(to Transponder Key ECU Assembly)

Front view of wire harness connector

(to Transponder Key Amplifier)

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	INSPECT TRANSPONDER KEY AMPLIFIER (POWER SOURCE AND GROUND)

(a) Reconnect the transponder key ECU assembly connector.

(b) Reconnect the transponder key amplifier connector.

Standard Voltage:

Tester Connection	Condition	Specified Condition
D22-14 (VC5) - Body ground	No key is in ignition key cylinder	Below 1 V
D22-14 (VC5) - Body ground	Key is in ignition key cylinder	4.6 to 5.4 V

Standard Resistance:

Tester Connection	Condition	Specified Condition
D22-5 (AGND) - Body ground	Always	Below 1 Ω

Text in Illustration

*1	Component with harness connected (Transponder Key ECU Assembly)

REPLACE TRANSPONDER KEY AMPLIFIER

REPLACE TRANSPONDER KEY ECU ASSEMBLY

Push Switch / Key Unlock Warning Switch Malfunction (B2780)

DESCRIPTION This DTC is stored if the transponder key ECU assembly does not detect that the unlock warning switch assembly is ON even when the ignition switch is ON. Under normal conditions, the ...

Transponder Chip Malfunction (B2793)

DESCRIPTION This DTC is stored when a malfunction is found in the key during key code registration or a key code is not registered normally. Replace the key if the key code registration is not pe ...

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