B2791

ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: B2791: Communication Condition Failure between ECM

DTC B2791 - Communication Condition Failure between ECM

DESCRIPTION

This DTC is output when the ID code box does not respond to a verification request signal from the hybrid vehicle control ECU.
HINT:
- If the power switch is turned off immediately after the hybrid control system starts, DTC B2791 will be detected. If DTC B2791 is cleared, this DTC will not recur because it does not indicate a malfunction.
- If this DTC B2791 is detected simultaneously with DTC B2799-542 or B2799-790, troubleshoot DTC B2799-542 or B2799-790 first.





WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE: If the engine can be started even when DTC B2791 is output, the ID code box can be considered normal. Be sure to recheck for DTCs after clearing the DTCs Programming and Relearning.

PROCEDURE

1. CHECK HYBRID CONTROL SYSTEM
(a) Delete the DTCs Reading and Clearing Diagnostic Trouble Codes.
(b) Check that the hybrid control system starts.
Result:





HINT: Perform this step when the is turned off immediately after the hybrid control system starts.

B -- END
A -- Continue to next step.
2. CHECK DTC OUTPUT
(a) Recheck for DTCs Reading and Clearing Diagnostic Trouble Codes.
Result:





HINT: If the hybrid control system does not start, DTC B2791 will not be detected separately from other DTCs because DTC B2791 will be output together with other DTCs. Troubleshoot DTCs other than DTC B2791.

B -- GO TO SMART KEY SYSTEM
A -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS