Dtc B2797 Communication Malfunction No. 1

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

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK KEYS

CHECK DTC

CHECK TRANSPONDER KEY ECU ASSEMBLY

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

REPLACE TRANSPONDER KEY AMPLIFIER

DTC B2797 Communication Malfunction No. 1


DESCRIPTION

This DTC is output when a communication error occurs between the transponder key amplifier and transponder key ECU. Some possible reasons for the communication error are: 1) 2 or more ignition keys are positioned too close together, or 2) noise is occurring in the communication line.

DTC No.
DTC Detection Condition
Trouble Area
B2797
Keys are positioned too close to each other, or noise occurred in communication line
  1. Key
  2. Wire harness
  3. Transponder key amplifier
  4. Transponder key ECU assembly

WIRING DIAGRAM


Yaris. Ncp93, 131.Theft Deterrent Keyless Entry.Engine Immobiliser System (For Sedan). Dtc B2797 Communication Malfunction No. 1


INSPECTION PROCEDURE

1.CHECK KEYS


    Yaris. Ncp93, 131

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

    Result:
    Result
    		Proceed to
    The key is near other keys and/or the key ring is in contact with the key grip.
    		A
    The key is not near other keys and/or the key ring is not in contact with the key grip.
    		B


B
Go to step 3
A


2.CHECK DTC

  1. Separate the keys from each other and/or remove the key ring.

  1. Delete the DTC (YARIS_NCP93 RM0000012F000PX.html).

  1. Insert a key into the ignition cylinder. Remove it. Repeat for all the other keys.

  1. Check that no code is output.

    OK:
    No code is output.


NG
Go to step 3
OK

END (INSPECTION FINISHED)

3.CHECK TRANSPONDER KEY ECU ASSEMBLY


    Yaris. Ncp93, 131.Theft Deterrent Keyless Entry.Engine Immobiliser System (For Sedan). Dtc B2797 Communication Malfunction No. 1

  1. Using an oscilloscope or the Techstream, check for noise in the waveform between the terminals of the D24 transponder key amplifier connector and D23 transponder key ECU connector.

    Result:
    Tester Connection
    		Specified Condition
    D23-15 (CODE) - D24-4 (CODE)
    		No noise is occur
    Tool Setting
    		5 V/DIV., 20 ms/DIV.
    Condition
    		Ignition switch
    OFF →
    ON


NG
FIND CAUSE OF NOISE AND REMOVE IT
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 B2797 Communication Malfunction No. 1

  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
    D23-15 (CODE) - D24-4 (CODE)
    		Below 1 Ω

  1. Reconnect the D23 transponder key ECU connector.

  1. Reconnect the D24 transponder 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)