CAN Communication System

NETWORKING: CAN COMMUNICATION SYSTEM: U1110: Lost Communication with Clearance Sonar Module
U1110 - Lost Communication with Clearance Sonar Module

DESCRIPTION





HINT
This diagnosis procedure is for when DTC U1110 is output by the power management control ECU (Techstream display: PM1 Gateway).

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* Turn the power switch off before measuring the resistances between CAN main bus lines and between CAN branch lines.
* Turn the power switch off before inspecting CAN bus lines 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 DTC U1002 is output from PM1 Gateway of the power management control ECU, this indicates a V2 bus malfunction. Troubleshoot for DTC U1002 and check for malfunctions in the V2 bus.

Result:





B -- GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC U1002
A -- Continue to next step.

2. CHECK CAN BUS LINE FOR DISCONNECTION (CLEARANCE WARNING ECU ASSEMBLY BRANCH LINE)

(a) Turn the power switch off.

(b) Disconnect the clearance warning ECU assembly connector.





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

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CLEARANCE WARNING ECU ASSEMBLY)
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

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





Standard Resistance:





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

Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

OK -- REPLACE CLEARANCE WARNING ECU ASSEMBLY Removal