Dtc B2796 No Communication In Immobiliser System

Vehicle Interior. Yaris. Ncp93, 131
Theft Deterrent Keyless Entry. Yaris. Ncp93, 131

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING TECHSTREAM

CHECK WHETHER ENGINE STARTS WITH OTHER KEYS

READ VALUE USING TECHSTREAM

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

REPLACE TRANSPONDER KEY AMPLIFIER

DTC B2796 No Communication in Immobiliser System

DTC B2798 Communication Malfunction No. 2


DESCRIPTION

This DTC is output when a key that does not have a transponder chip is inserted into the ignition key cylinder or if communication between the key and transponder key ECU is not possible.

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


Yaris. Ncp93, 131.Theft Deterrent Keyless Entry.Engine Immobiliser System (For Sedan). Dtc B2796 No Communication In Immobiliser System


INSPECTION PROCEDURE

1.READ VALUE USING TECHSTREAM

  1. Connect a Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

  1. Enter the following menus: Body Electrical / Immobiliser / Data List.

  1. According to the display on tester, read the "Data List".


Immobiliser:
Tester Display
Measurement Item/Range
Normal Condition
Diagnostic Note
Immobiliser
Immobiliser system status/
SET or UNSET
UNSET: Ignition switch ON
SET: Without key
-
OK:
"UNSET" (ignition switch ON) appears on the screen.


NG
Go to step 2
OK

REPLACE TRANSPONDER KEY ECU ASSEMBLY (YARIS_NCP93 RM000003BHZ005X.html)

2.CHECK WHETHER ENGINE STARTS WITH OTHER KEYS

  1. Check whether the engine starts with the vehicle's other keys.

    OK:
    Engine starts.


NG
Go to step 3
OK

RE-REGISTER OR REPLACE KEY THAT CANNOT START ENGINE

3.READ VALUE USING TECHSTREAM

  1. Connect a Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

  1. Enter the following menus: Body Electrical / Immobiliser / Data List.

  1. According to the display on tester, read the "Data List".


Immobiliser:
Tester Display
Measurement Item/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.


NG
REPLACE TRANSPONDER KEY AMPLIFIER
OK


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


    Yaris. Ncp93, 131.Theft Deterrent Keyless Entry.Engine Immobiliser System (For Sedan). Dtc B2796 No Communication In Immobiliser System

  1. Disconnect the D23 transponder key ECU connector.

  1. Disconnect the D24 transponder key amplifier connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    D23-14 (VC5) - D24-1 (VC5)
    		Below 1 Ω
    D23-15 (CODE) - D24-4 (CODE)
    		Below 1 Ω
    D23-4 (TXCT) - D24-5 (TXCT)
    		Below 1 Ω
    D23-5 (AGND) - D24-7 (AGND)
    		Below 1 Ω
    D23-14 (VC5) or D24-1 (VC5) -
    Body ground
    		10 kΩ or higher
    D23-15 (CODE) or D24-4 (CODE) -
    Body ground
    		10 kΩ or higher
    D23-4 (TXCT) or D24-5 (TXCT) -
    Body ground
    		10 kΩ or higher
    D23-5 (AGND) or D24-7 (AGND) -
    Body ground
    		10 kΩ or higher

  1. Reconnect the D23 transponder key ECU connector.

  1. Reconnect the D24 transponder key amplifier connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.REPLACE TRANSPONDER KEY AMPLIFIER

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

    OK:
    Engine starts.


NG
REPLACE TRANSPONDER KEY ECU ASSEMBLY (YARIS_NCP93 RM000003BHZ005X.html)
OK

END (TRANSPONDER KEY AMPLIFIER DEFECTIVE)