CAN Communication System

NETWORKING: CAN COMMUNICATION SYSTEM: U0293, U0100: Lost Communication with HV ECU
U0100 - Lost Communication with ECM

DESCRIPTION





HINT
The diagnosis procedure is for when DTC U0100 or U0293 is output by the power management control ECU (Techstream display: Power Management1).

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* Turn the power switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.
* Turn the power switch off before inspecting CAN bus wires for a ground short.
* After the power switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.
* Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power switch, any other switches or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.

HINT
* Operating the power switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
* Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

1. RECONFIRM DTC OUTPUT

(a) Reconfirm DTCs.

HINT
If CAN No. 2 bus DTC U1002 is output from the power management control ECU (Techstream display/Power Management1), troubleshoot for U1002 and check for malfunctions in the CAN No. 2 main bus circuit.

Result:





B -- GO TO CIRCUITS INDICATED BY OUTPUT DTCS CAN Communication System
A -- Continue to next step.

2. CHECK CAN BUS WIRE FOR DISCONNECTION (HYBRID VEHICLE CONTROL ECU MAIN WIRE/CAN NO. 2 BUS)

(a) Turn the power switch off.

(b) Disconnect the hybrid vehicle control ECU connector.





Text in Illustration





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

Standard Resistance:





NG -- REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (HYBRID VEHICLE CONTROL ECU)
OK -- Continue to next step.

3. CHECK ECM POWER SOURCE CIRCUIT

(a) Check the ECM (hybrid vehicle control ECU) power source circuit ECM Power Source Circuit.

NG -- REPAIR POWER SOURCE RESET (HYBRID VEHICLE CONTROL ECU)

OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal