Toyota Sienna Service Manual: No Communication in Immobiliser System

DTC B2796 No Communication in Immobiliser System

DTC B2798 Communication Malfunction No. 2

DESCRIPTION

These codes are stored in the memory when a key that does not have a transponder chip is inserted or if communication between the key and transponder key ECU is impossible.

WIRING DIAGRAM

INSPECTION PROCEDURE

1 READ VALUE OF INTELLIGENT TESTER

1. Connect the intelligent tester (with CAN VIM) to the DLC3.
2. Turn the ignition switch on and turn the intelligent tester main switch on.
3. Select IMMOBILISER in the DATA LIST and read the value displayed on the intelligent tester.

Transponder key ECU:

OK: UNSET (Ignition switch on) appears on the screen.

2 CHECK KEYS

1. Insert the vehicle's other key into the ignition key cylinder.
2.  Check that the engine starts with this key.

OK: The engine starts

3 READ VALUE OF INTELLIGENT TESTER

1. Connect the intelligent tester (with CAN VIM) to the DLC3.
2.  Turn the ignition switch on and turn the intelligent tester main switch on.
3.  Select ANTENNA COIL in the DATA LIST and read the value displayed on the intelligent tester

Transponder key ECU:

OK: NORMAL (Antenna coil is normal) appears on the screen.

4 CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - TRANSPONDER KEY AMPLIFIER)

1. Disconnect the T6 ECU and I14 amplifier connectors.
2.  Measure the resistance according to the value(s) in the table below.

Resistance

5 INSPECT TRANSPONDER KEY ECU ASSEMBLY

1. Reconnect the T6 ECU and I14 amplifier connectors.
2.  Measure the voltage according to the value(s) in the table below.

Voltage

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

Resistance

6 REPLACE TRANSPONDER KEY AMPLIFIER

1. After replacing the transponder key amplifier with a normally functioning transponder key amplifier, check that the engine starts.

OK: The engine starts.

END (TRANSPONDER KEY AMPLIFIER DEFECTIVE)

DTC B2797 Communication Malfunction No. 1

DESCRIPTION

This DTC is output when an error occurs in normal communication.

HINT: Some noise found in the communication line.

WIRING DIAGRAM

INSPECTION PROCEDURE

1 CHECK KEY

1. Check whether the ignition key being used is near other ignition keys, as shown in the illustration. Also, check whether the key ring is in contact with the key grip.

Result

2 CHECK DTC OUTPUT

1. Delete the DTC
2. Insert the key into the ignition key cylinder.
3.  Check that no code is output.

OK: No DTC is output.

3 CHECK TRANSPONDER KEY AMPLIFIER

1. Using an oscilloscope or the intelligent tester, check the waveform between the terminals of the I14 amplifier and T6 ECU connector.

   Check that no noise is included in the waveform (an example of noise is shown on the left).

2.  Check that no noise is included in the waveform (an example of noise is shown on the left).

Result

4 CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)

1. Disconnect the T6 ECU and I14 amplifier connectors.
2.  Measure the resistance according to the value(s) in the table below.

Resistance

5 REPLACE TRANSPONDER KEY AMPLIFIER

1. After replacing the transponder key amplifier with a normally functioning transponder key amplifier, check that the engine starts.

OK: The engine starts

END (TRANSPONDER KEY AMPLIFIER DEFECTIVE)