B2797

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 assembly. Some possible reasons for the communication error are: 1) 2 or more ignition keys are positioned too close to each other, 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.
Result:





B -- CHECK TRANSPONDER KEY ECU ASSEMBLY
A -- Continue to next step.
2. CHECK DTC OUTPUT
(a) Separate the keys from each other. 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. Perform this step for all the other keys.
(d) Check that no code is output.
OK -- END
NG -- Continue to next step.
3. CHECK TRANSPONDER KEY ECU ASSEMBLY





(a) Using an oscilloscope or Techstream, check the waveform between the terminals of the T9 amplifier connector and T10 ECU connector. The waveform should be similar to the illustration on the left.
Result:









NG -- FIND CAUSE OF NOISE AND REMOVE IT
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR





(a) Disconnect the T10 ECU and T9 amplifier connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. CHECK TRANSPONDER KEY AMPLIFIER
(a) After replacing the transponder key amplifier with a normally functioning amplifier, check that the engine starts.
OK:
The engine starts.
NG -- REPLACE TRANSPONDER KEY ECU ASSEMBLY
OK -- END