Short to B+ in CAN Bus Line
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 line and +B when there is resistance between terminals 6 (CANH) and 16 (BAT) or terminals 14 (CANL) and 16 (BAT) of the DLC3.
HINT: *: w/ Navigation System
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT: Operating the engine 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 resistances of the main wire and the branch wire.
CAUTION: Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.
NEXT -- Continue to next step.
2. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (DLC3 BRANCH WIRE)
(a) Disconnect the E75 No. 3 junction connector connector.
(b) Measure the resistance according to the value(s) in the table below.
Result
NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3 (CANH, CANL)
OK -- Continue to next step.
3. CONNECT CONNECTOR
(a) Reconnect the E75 No. 3 junction connector connector.
NEXT -- Continue to next step.
4. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 1 JUNCTION CONNECTOR SIDE)
(a) Disconnect the E72 No. 1 junction connector connector.
(b) Measure the resistance according to the value(s) in the table below.
Result
NG -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 1 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)
OK -- Continue to next step.
5. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 1 JUNCTION CONNECTOR - CENTER AIRBAG SENSOR)
(a) Measure the resistance according to the value(s) in the table below.
NG -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CENTER AIRBAG SENSOR)
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.
NG -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECM)
OK -- REPAIR OR REPLACE NO. 1 JUNCTION CONNECTOR
7. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CENTER AIRBAG SENSOR)
(a) Disconnect the E47 center airbag sensor connector.
(b) Measure the resistance according to the value(s) in the table below.
Result
NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO CENTER AIRBAG SENSOR (CANH, CANL)
OK -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY
8. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECM)
(a) Disconnect the A38 ECM connector.
(b) Measure the resistance according to the value(s) in the table below.
Result
NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO ECM (CANH, CANL)
OK -- REPLACE ECM
9. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 1 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)
(a) Disconnect the E69 No. 2 junction connector connector.
(b) Measure the resistance according to the value(s) in the table below.
Result
NG -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 1 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)
OK -- Continue to next step.
10. CONNECT CONNECTOR
(a) Reconnect the E72 No. 1 junction connector connector.
NEXT -- Continue to next step.
11. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 JUNCTION CONNECTOR SIDE)
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR)
OK -- Continue to next step.
12. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 JUNCTION CONNECTOR - MULTI-DISPLAY)
NOTE: For vehicles without the navigation system, go to "Check for Short to B+ in CAN Bus Wire (No. 2 Junction Connector - Air Conditioning Amplifier)".
(a) Measure the resistance according to the value(s) in the table below.
NG -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (MULTI-DISPLAY)
OK -- Continue to next step.
13. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 JUNCTION CONNECTOR - AIR CONDITIONING AMPLIFIER)
(a) Measure the resistance according to the value(s) in the table below.
NG -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (AIR CONDITIONING AMPLIFIER)
OK -- Continue to next step.
14. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 JUNCTION CONNECTOR - NETWORK GATEWAY ECU)
(a) Measure the resistance according to the value(s) in the table below.
NG -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NETWORK GATEWAY ECU)
OK -- REPAIR OR REPLACE NO. 2 JUNCTION CONNECTOR
15. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (MULTI-DISPLAY)
(a) Disconnect the F28 multi-display connector.
(b) Measure the resistance according to the value(s) in the table below.
Result
NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MULTI-DISPLAY (CANH, CANL)
OK -- REPLACE MULTI-DISPLAY
16. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (AIR CONDITIONING AMPLIFIER)
(a) Disconnect the E35 air conditioning amplifier connector.
(b) Measure the resistance according to the value(s) in the table below.
Result
NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO AIR CONDITIONING AMPLIFIER (CANH, CANL)
OK -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
17. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NETWORK GATEWAY ECU)
(a) Disconnect the E31 network gateway ECU.
(b) Measure the resistance according to the value(s) in the table below.
Result
NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO NETWORK GATEWAY ECU (CANH, CANL)
OK -- REPLACE NETWORK GATEWAY ECU
18. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR)
(a) Disconnect the E75 No. 3 junction connector connector.
(b) Measure the resistance according to the value(s) in the table below.
Result
NG -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 2 JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR)
OK -- Continue to next step.
19. CONNECT CONNECTOR
(a) Reconnect the E69 No. 2 junction connector connector.
NEXT -- Continue to next step.
20. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 3 JUNCTION CONNECTOR - MAIN BODY ECU)
(a) Measure the resistance according to the value(s) in the table below.
NG -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (MAIN BODY ECU)
OK -- Continue to next step.
21. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 3 JUNCTION CONNECTOR - COMBINATION METER)
(a) Measure the resistance according to the value(s) in the table below.
NG -- CHECK FOR SHORT TO B+ IN CAN BUS WIRE (COMBINATION METER)
OK -- REPAIR OR REPLACE NO. 3 JUNCTION CONNECTOR
22. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (MAIN BODY ECU)
(a) Disconnect the E3 main body ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Result
NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH) (CANH, CANL)
OK -- REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)
23. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (COMBINATION METER)
(a) Disconnect the E7 combination meter connector.
(b) Measure the resistance according to the value(s) in the table below.
Result
NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO COMBINATION METER (CANH, CANL)
OK -- REPLACE COMBINATION METER ASSEMBLY