Dtc B2797 Communication Malfunction No. 1


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK KEY

CHECK FOR DTC

CHECK TRANSPONDER KEY ECU

CHECK WIRE HARNESS (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)

CHECK TRANSPONDER KEY AMPLIFIER (OPERATION)

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

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Engine Immobiliser.Engine Immobiliser System. Dtc B2797 Communication Malfunction No. 1


INSPECTION PROCEDURE

1.CHECK KEY
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50

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

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


B
Go to step 3
A


2.CHECK FOR DTC

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

  1. Delete the DTC (Toyota Fortuner RM000000Z3I004X.html).

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

  1. Check that no DTC is output.

    OK:
    No DTC is output.


OK
NORMAL
NG


3.CHECK TRANSPONDER KEY ECU
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Engine Immobiliser.Engine Immobiliser System. Dtc B2797 Communication Malfunction No. 1

  1. Using an oscilloscope or the intelligent tester, check for noise in the waveform between the terminals of the T20 amplifier connector and T21 ECU connector.

    OK:
    No noise is present (see illustration).
    Tester Connection
    		Tool Setting
    		Condition
    		Specified Condition
    T21-15 (CODE) - T20-4 (CODE)
    		5 V/DIV., 20 msec./DIV.
    		Key inserted
    		No noise is present


NG
FIND CAUSE OF NOISE AND REMOVE IT
OK


4.CHECK WIRE HARNESS (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Engine Immobiliser.Engine Immobiliser System. Dtc B2797 Communication Malfunction No. 1

  1. Disconnect the T21 ECU connector.

  1. Disconnect the T20 amplifier connector.

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

    Standard resistance:
    Tester Connection
    		Specified Condition
    T21-15 (CODE) - T20-4 (CODE)
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.CHECK TRANSPONDER KEY AMPLIFIER (OPERATION)

  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
OK

END (TRANSPONDER KEY AMPLIFIER DEFECTIVE)