B2799-542

DESCRIPTION

These DTCs are output when the hybrid vehicle control ECU detects errors in communication between the transponder key ECU and the hybrid vehicle control ECU, and in the communication lines. These DTCs are also output when a hybrid control system start is attempted while the ECU communication ID between the transponder key ECU and the hybrid vehicle control ECU are different. Before troubleshooting for DTCs, make sure that there is no DTC detected in the transponder key ECU. If there is key code related DTC detected in the transponder key ECU, repair it first.

DTC No.	DTC Detection Condition	Trouble Area
B2799-542 B2799-790	Error in communication between hybrid vehicle control ECU and transponder key ECU, and in communication line. Communication ID is different during communication with transponder key ECU.	Wire harness Transponder key ECU assembly Hybrid vehicle control ECU

WIRING DIAGRAM

INSPECTION PROCEDURE

1. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - HYBRID VEHICLE CONTROL ECU)

1. Disconnect the T8 ECU and H29 hybrid vehicle control ECU connectors.

2. Measure the resistance according to the value(s) in the table below.

   Resistance:

   Tester Connection	Specified Condition
   T8-6 (EFIO) - H29-22 (IMI)	Below 1 Ω
   T8-7 (EFII) - H29-28 (IMO)
   T8-6 (EFIO) or H29-22 (IMI) - Body ground	10 kΩ or higher
   T8-7 (EFII) or H29-28 (IMO) - Body ground

3. Measure the voltage according to the value(s) in the table below.

   Voltage:

   Tester Connection	Condition	Specified Condition
   T8-6 (EFIO) or H29-22 (IMI) - H32-5 (E1)	Ignition switch on	Below 1 V
   T8-7 (EFII) or H29-28 (IMO) - H32-5 (E1)

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

2. RE-REGISTRATION ECU COMMUNICATION ID (TRANSPONDER KEY ECU ASSEMBLY - HYBRID VEHICLE CONTROL ECU)

1. Re-register the ECU communication ID.

2. Check that the hybrid control system starts.

   OK:

   Hybrid control system starts.
   

OK	NO PROBLEM

NG

3. CHECK OPERATION OF TRANSPONDER KEY ECU ASSEMBLY

1. After replacing the transponder key ECU assembly with a normally functioning transponder key ECU assembly, check that the hybrid control system starts.

   OK:

   Hybrid control system starts.
   

NG	REPLACE HYBRID VEHICLE CONTROL ECU

OK
END (TRANSPONDER KEY ECU ASSEMBLY DEFECTIVE)