Part 1
NETWORKING: CAN COMMUNICATION SYSTEM: Short to B+ in CAN Bus Line
- Short to B+ in CAN Bus Line
DESCRIPTION
There may be a short circuit between the CAN bus lines and +B when the resistance between terminals 6 (CANH) and 16 (BAT) or terminals 14 (CANL) and 16 (BAT) of the DLC3 is below 6 kOhms.
* *: w/ Smart Key System
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT
Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.
PROCEDURE
1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL
(a) Disconnect the cable from the negative (-) battery terminal before measuring the resistance of the CAN main wire and CAN branch wire.
CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.
NOTICE:
When disconnecting the cable, some systems need to be initialized after the cable is reconnected Repair Instruction - Initialization.
NEXT -- Continue to next step.
2. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (DLC3 CAN BRANCH WIRE)
(a) Disconnect the C65 No. 2 junction connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3 (CANH, CANL)
OK -- Continue to next step.
3. CONNECT CONNECTOR
(a) Reconnect the C65 No. 2 junction connector.
NEXT -- Continue to next step.
4. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 1 JUNCTION CONNECTOR SIDE)
(a) Disconnect the A34 No. 1 junction connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- CONNECT CONNECTOR
OK -- Continue to next step.
5. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 1 JUNCTION CONNECTOR - SKID CONTROL ECU)
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- CONNECT CONNECTOR
OK -- Continue to next step.
6. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 1 JUNCTION CONNECTOR - ECM)
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- CONNECT CONNECTOR
OK -- REPLACE NO. 1 JUNCTION CONNECTOR
7. CONNECT CONNECTOR
(a) Reconnect the A34 No. 1 junction connector.
NEXT -- Continue to next step.
8. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (SKID CONTROL ECU)
(a) Disconnect the A36 brake actuator assembly (skid control ECU) connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO SKID CONTROL ECU (CANH, CANL)
OK -- REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) Removal
9. CONNECT CONNECTOR
(a) Reconnect the A34 No. 1 junction connector.
NEXT -- Continue to next step.
10. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECM)
(a) Disconnect the A35 ECM connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ECM (CANH, CANL)
OK -- REPLACE ECM Removal
11. CONNECT CONNECTOR
(a) Reconnect the A34 No. 1 junction connector.
NEXT -- Continue to next step.
12. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 JUNCTION CONNECTOR - NO. 1 JUNCTION CONNECTOR)
(a) Disconnect the C65 No. 2 junction connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 2 JUNCTION CONNECTOR - NO. 1 JUNCTION CONNECTOR)
OK -- Continue to next step.
13. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 JUNCTION CONNECTOR - CERTIFICATION ECU)
NOTICE:
For vehicles without a smart key system, go to "Check for Short to B+ in CAN Bus Wire (No. 2 Junction Connector - Power Steering ECU Assembly)".
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- CONNECT CONNECTOR
OK -- Continue to next step.
14. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 JUNCTION CONNECTOR - POWER STEERING ECU ASSEMBLY)
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- CONNECT CONNECTOR
OK -- Continue to next step.
15. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 JUNCTION CONNECTOR - AIR CONDITIONING AMPLIFIER ASSEMBLY)
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- CONNECT CONNECTOR
OK -- Continue to next step.