Part 1
NETWORKING: CAN COMMUNICATION SYSTEM: Check CAN Bus Line for Short to GND
- Check CAN Bus Line for Short to GND
DESCRIPTION
There may be a short circuit between the CAN bus line and GND when there is no resistance between terminals 6 (CANH) and 4 (CG) or terminals 14 (CANL) and 4 (CG) of the DLC3.
*1: w/ Network gateway ECU
*2: w/o Network gateway ECU
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
* Turn the ignition switch off before measuring the resistances of the CAN main wire and the CAN branch wire.
* After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
* Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If the doors need to be opened in order to check the connectors, open the doors and leave them open.
HINT
* Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes the resistance variation.
* 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 will help determine the cause of the malfunction.
PROCEDURE
1. CHECK FOR SHORT TO GND IN CAN BUS WIRE (DLC3 BRANCH WIRE)
(a) Turn the ignition switch off.
(b) Disconnect the CAN No. 1 junction connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3
OK -- Continue to next step.
2. CHECK FOR SHORT TO GND IN CAN BUS WIRE (CAN NO. 2 JUNCTION CONNECTOR)
(a) Turn the ignition switch off.
(b) Reconnect the CAN No. 1 junction connector.
(c) Disconnect the CAN No. 2 junction connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- CHECK FOR SHORT TO GND IN CAN BUS WIRE (POWER STEERING ECU BRANCH WIRE)
OK -- Continue to next step.
3. CHECK FOR SHORT TO GND IN CAN BUS WIRE (ECM MAIN WIRE)
(a) Measure the resistance according to the value(s) in the table below.
HINT
The resistance must be measured after the CAN No. 2 junction connector is disconnected.
Standard Resistance:
NG -- CHECK FOR SHORT TO GND IN CAN BUS WIRE (ECM MAIN WIRE)
OK -- Continue to next step.
4. CHECK FOR SHORT TO GND IN CAN BUS WIRE (SKID CONTROL ECU BRANCH WIRE)
(a) Disconnect the skid control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
HINT
The resistance must be measured after the CAN No. 2 junction connector is disconnected.
Standard Resistance:
Result:
C -- REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 2 JUNCTION CONNECTOR - SKID CONTROL ECU)
B -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal
A -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal
5. CHECK FOR SHORT TO GND IN CAN BUS WIRE (ECM MAIN WIRE)
(a) Disconnect the ECM connector.
(b) Measure the resistance according to the value(s) in the table below.
HINT
The resistance must be measured after the CAN No. 2 junction connector is disconnected.
Standard resistance:
Result:
C -- REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 2 JUNCTION CONNECTOR - ECM)
B -- REPLACE ECM Removal
A -- REPLACE ECM Removal
6. CHECK FOR SHORT TO GND IN CAN BUS WIRE (POWER STEERING ECU BRANCH WIRE)
(a) Reconnect the CAN No. 2 junction connector.
(b) Disconnect the CAN No. 1 junction connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- CHECK FOR SHORT TO GND IN CAN BUS WIRE (CAN NO. 1 JUNCTION CONNECTOR - POWER STEERING ECU)
OK -- Continue to next step.
7. CHECK FOR SHORT TO GND IN CAN BUS WIRE (STEERING ANGLE SENSOR BRANCH WIRE)
(a) Measure the resistance according to the value(s) in the table below.
HINT
The resistance must be measured after the CAN No. 1 junction connector is disconnected.
Standard Resistance:
NG -- CHECK FOR SHORT TO GND IN CAN BUS WIRE (CAN NO. 1 JUNCTION CONNECTOR - STEERING ANGLE SENSOR)
OK -- Continue to next step.
8. CHECK FOR SHORT TO GND IN CAN BUS WIRE (YAW RATE SENSOR BRANCH WIRE)
(a) Measure the resistance according to the value(s) in the table below.
HINT
The resistance must be measured after the CAN No. 1 junction connector is disconnected.
Standard Resistance:
NG -- CHECK FOR SHORT TO GND IN CAN BUS WIRE (CAN NO. 1 JUNCTION CONNECTOR - YAW RATE SENSOR)
OK -- Continue to next step.
9. CHECK FOR SHORT TO GND IN CAN BUS WIRE (MAIN BODY ECU BRANCH WIRE)
(a) Measure the resistance according to the value(s) in the table below.
HINT
The resistance must be measured after the CAN No. 1 junction connector is disconnected.
Standard resistance:
NG -- CHECK FOR SHORT TO GND IN CAN BUS WIRE (CAN NO. 1 JUNCTION CONNECTOR - MAIN BODY ECU)
OK -- Continue to next step.
10. CHECK FOR SHORT TO GND IN CAN BUS WIRE (AIR CONDITIONING AMPLIFIER BRANCH WIRE)
(a) Measure the resistance according to the value(s) in the table below.
HINT
The resistance must be measured after the CAN No. 1 junction connector is disconnected.
Standard resistance:
NG -- CHECK FOR SHORT TO GND IN CAN BUS WIRE (CAN NO. 1 JUNCTION CONNECTOR - AIR CONDITIONING AMPLIFIER)
OK -- Continue to next step.
11. CHECK FOR SHORT TO GND IN CAN BUS WIRE (CENTER AIRBAG SENSOR ASSEMBLY BRANCH WIRE)
(a) Measure the resistance according to the value(s) in the table below.
HINT
The resistance must be measured after the CAN No. 1 junction connector is disconnected.
Standard resistance:
NG -- CHECK FOR SHORT TO GND IN CAN BUS WIRE (CAN NO. 1 JUNCTION CONNECTOR - CENTER AIRBAG SENSOR ASSEMBLY)
OK -- Continue to next step.