B2797

ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: B2797: Communication Malfunction No. 1

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.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK KEYS




(a) 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.






B -- CHECK TRANSPONDER KEY ECU ASSEMBLY
A -- Continue to next step.

2. CHECK FOR DTCS
(a) Separate the keys from each other and/or remove the key ring.
(b) Delete the DTC Reading and Clearing Diagnostic Trouble Codes.
(c) Insert a key into the ignition cylinder. Remove it. Repeat for all the other keys.
(d) Check that no code is output.
OK:
No code is output.
OK -- NORMAL (INSPECTION FINISHED)
NG -- Continue to next step.

3. CHECK TRANSPONDER KEY ECU ASSEMBLY




(a) Using an oscilloscope or the intelligent tester check for noise in the waveform between the terminals of the T9 amplifier connector and T10 ECU connector.
OK:
No noise is present (see illustration).










NG -- FIND CAUSE OF NOISE AND REMOVE IT
OK -- Continue to next step.

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




(a) Disconnect the T10 ECU connector.
(b) Disconnect the T9 amplifier connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:





(d) Reconnect the ECU connector.
(e) Reconnect the amplifier connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. REPLACE TRANSPONDER KEY AMPLIFIER (OPERATION)
(a) After replacing the transponder key amplifier with a normally functioning amplifier Removal, check that the engine starts.
OK:
Engine starts.
NG -- REPLACE TRANSPONDER KEY ECU ASSEMBLY
OK -- END (TRANSPONDER KEY AMPLIFIER DEFECTIVE)