Short to B+ in CAN Bus Line

CAN COMMUNICATION SYSTEM: Short to B+ in CAN Bus Line

Short to B+ in CAN Bus Line

DESCRIPTION

A short to B+ is suspected in the CAN bus wire when the resistance between terminals 6 (CANH) and 16 (BAT), or terminals 14 (CANL) and 16 (BAT) of the DLC3 is below 6 kOhms.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTE: Turn the ignition switch off before measuring the resistances of CAN bus main wires and CAN bus branch wires.

PROCEDURE

1. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CAN BUS MAIN WIRE)
(a) Turn the ignition switch off, and disconnect the negative battery terminal.
(b) Disconnect the CAN junction connector.





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





Result:





C -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (SKID CONTROL ECU)
B -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECM)
A -- Continue to next step.
2. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CAN BUS BRANCH EIRE)





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





Result:





D -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (YAW RATE SENSOR)
C -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (STEERING ANGLE SENSOR)
B -- REPAIR OR REPLACE DLC3 BRANCH WIRE OR CONNECTOR
A -- REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN JUNCTION CONNECTOR)
3. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECM)





(a) Disconnect the ECM connector (E5).





(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM
4. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (SKID CONTROL ECU)





(a) Disconnect the skid control ECU connector.





(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE SKID CONTROL ECU WITH ACTUATOR
5. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (STEERING ANGLE SENSOR)





(a) Disconnect the steering angle sensor connector.





(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE STEERING ANGLE SENSOR
6. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (YAW RATE SENSOR)





(a) Disconnect the yaw rate sensor connector.





(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE YAW RATE SENSOR