GSIC - Global Service Information Center

### 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

## INSPECTION PROCEDURE

1.CHECK KEY

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 (Click here).

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.

| OK |

NORMAL

NG |

3.CHECK TRANSPONDER KEY ECU ASSEMBLY

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 ASSEMBLY - TRANSPONDER KEY AMPLIFIER)

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 AND CONNECTOR

OK |

5.CHECK OPERATION OF 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

OK |

END (TRANSPONDER KEY AMPLIFIER DEFECTIVE)