RX400h · Service Manual SECURITIES

B2796 No communication

Diagnostic trouble codes

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.
DTC No.
 DTC Detection Condition
 Trouble Area
B2796
 No communication
  1. Key
  2. Wire harness
  3. Transponder key amplifier
  4. Transponder key ECU assembly
B2798
 Communication error
 Key

WIRING DIAGRAM

B111588E05

INSPECTION PROCEDURE


1. READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch on and turn the intelligent tester main switch on.

  1. Select Immobilizer in the DATA LIST and read the value displayed on the intelligent tester.

    Transponder key ECU: 
    Item
    		 Measurement Item/Display (Range)
    		 Normal Condition
    		 Diagnostic Note
    Immobiliser
    		 Immobiliser system status / SET or UNSET
    		 UNSET: Ignition switch on
    SET: Without key
    		 -

    OK:
    Both UNSET (Ignition switch on) and SET (Without key) appear on the screen.



 OK
REPLACE TRANSPONDER KEY ECU ASSEMBLY
NG


2. CHECK WHETHER HYBRID CONTROL SYSTEM STARTS WITH OTHER KEYS

  1. Insert the vehicle's other key into the ignition key cylinder.

  1. Check that the hybrid control system starts with this key.

    OK:
    Hybrid control system starts.



 OK
RE-REGISTER OR REPLACE KEY
NG


3. READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch on and turn the intelligent tester main switch on.

  1. Select Antenna Coil Status in the DATA LIST and read the value displayed on the intelligent tester.

    Transponder key ECU: 
    Item
    		 Measurement Item/Display (Range)
    		 Normal Condition
    		 Diagnostic Note
    Antenna Coil Status
    		 Antenna coil condition /NORMAL or FAIL
    		 NORMAL: Antenna coil is normal.
    FAIL: Antenna coil is malfunctioning.
    		 -

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



 OK
REPLACE TRANSPONDER KEY ECU ASSEMBLY
NG


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

  1. B111591E03
    Disconnect the T8 ECU and T7 amplifier connectors.

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

    Resistance:
    Tester Connection
    		 Specified Condition
    T8-9 (VC5) - T7-1 (VC5)
    		 Below 1 Ω
    T8-10 (CODE) - T7-4 (CODE)
    T8-12 (TXCT) - T7-5 (TXCT)
    T8-13 (AGND) - T7-7 (GND)
    T8-9 (VC5) or T7-1 (VC5) - Body ground
    		 10 kΩ or higher
    T8-10 (CODE) or T7-4 (CODE) - Body ground
    T8-12 (TXCT) or T7-5 (TXCT) - Body ground
    T8-13 (AGND) or T7-7 (GND) - Body ground



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5. INSPECT TRANSPONDER KEY ECU ASSEMBLY

  1. B111616E07
    Reconnect the T8 ECU and T7 amplifier connectors.

  1. Measure the voltage according to the value(s) in the table below.

    Voltage:
    Tester Connection
    		 Condition
    		 Specified Condition
    T8-9 (VC5) - Body ground
    		 No key is in ignition key cylinder
    		 Below 1 V
    Key is in ignition key cylinder
    		 4.6 to 5.4 V

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

    Resistance:
    Tester Connection
    		 Condition
    		 Specified Condition
    T8-13 (AGND) - Body ground
    		 Always
    		 Below 1 Ω



NG
REPLACE TRANSPONDER KEY ECU ASSEMBLY
OK


6. CHECK OPERATION OF TRANSPONDER KEY AMPLIFIER

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

    OK:
    Hybrid control system starts.



 NG
REPLACE TRANSPONDER KEY ECU ASSEMBLY
OK

END (TRANSPONDER KEY AMPLIFIER DEFECTIVE)


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