- Short to +B
- ECM
- Center airbag sensor assembly
- AFS ECU (headlight swivel ECU assembly)
- Display and navigation module display*1
- Multi-display*2
- Air conditioning amplifier assembly
- Network gateway ECU
- Main body ECU (cowl side junction block LH)
- Combination meter assembly
- No. 1 junction connector
- No. 2 junction connector
- No. 3 junction connector
| Last Modified: 11-27-2007 | 1.6 J | |
| Service Category: Power Source/Network | Section: Networking | |
| Model Year: 2008 | Model: LX570 | Doc ID: RM000002L8000EX |
| Title: NETWORKING: CAN COMMUNICATION SYSTEM: DESCRIPTION (2008 LX570) | ||
|
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.
|
Symptom |
Trouble Area |
|---|---|
|
There is resistance between terminals 6 (CANH) and 16 (BAT) or terminals 14 (CANL) and 16 (BAT) of the DLC3. |
|
*1: w/ Navigation System
*2: w/o 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.
NOTICE:
-
w/ Navigation System:
After the engine switch is turned off, the HDD navigation system requires approximately 6 minutes to record various types of memory and settings. As a result, after turning the engine switch off, wait 6 minutes or more before disconnecting the cable from the negative (-) battery terminal.
-
When disconnecting the cable, some systems need to be initialized after the cable is reconnected
.
|
|
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
|
Tester Connection |
Switch Condition |
Measured Resistance |
Proceed to |
|---|---|---|---|
|
E22-6 (CANH) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E22-14 (CANL) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E22-6 (CANH) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
E22-14 (CANL) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
|
3. |
CONNECT CONNECTOR |
(a) Reconnect the E75 No. 3 junction connector connector.
|
|
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
|
Tester Connection |
Switch Condition |
Measured Resistance |
Result |
|---|---|---|---|
|
E22-6 (CANH) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E22-14 (CANL) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E22-6 (CANH) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
E22-14 (CANL) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
|
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.
|
|
|
6. |
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 1 JUNCTION CONNECTOR - AFS ECU) |
|
(a) Measure the resistance according to the value(s) in the table below.
|
|
|
7. |
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.
|
|
|
8. |
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
|
Tester Connection |
Switch Condition |
Measured Resistance |
Proceed to |
|---|---|---|---|
|
E72-4 (CANH) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E72-15 (CANL) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E72-4 (CANH) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
E72-15 (CANL) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
|
9. |
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (AFS ECU) |
(a) Disconnect the E91 AFS ECU (headlight swivel ECU) connector.
(b) Measure the resistance according to the value(s) in the table below.
Result
|
Tester Connection |
Switch Condition |
Measured Resistance |
Proceed to |
|---|---|---|---|
|
E72-3 (CANH) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E72-14 (CANL) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E72-3 (CANH) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
E72-14 (CANL) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
|
10. |
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
|
Tester Connection |
Switch Condition |
Measured Resistance |
Proceed to |
|---|---|---|---|
|
E72-2 (CANH) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E72-13 (CANL) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E72-2 (CANH) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
E72-13 (CANL) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
|
11. |
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
|
Tester Connection |
Switch Condition |
Measured Resistance |
Proceed to |
|---|---|---|---|
|
E69-1 (CANH) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E69-12 (CANL) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E69-1 (CANH) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
E69-12 (CANL) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
|
12. |
CONNECT CONNECTOR |
(a) Reconnect the E72 No. 1 junction connector connector.
|
|
13. |
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:
|
|
|
14. |
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 JUNCTION CONNECTOR - DISPLAY AND NAVIGATION MODULE DISPLAY OR MULTI-DISPLAY |
|
(a) Measure the resistance according to the value(s) in the table below.
|
|
|
15. |
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.
|
|
|
16. |
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.
|
|
|
17. |
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (DISPLAY AND NAVIGATION MODULE DISPLAY OR MULTI-DISPLAY) |
|
|
(a) Disconnect the F28 display and navigation module display*1 or multi-display*2 connector. *1: w/ Navigation System *2: w/o Navigation System |
(b) Measure the resistance according to the value(s) in the table below.
Result
|
Tester Connection |
Switch Condition |
Measured Resistance |
Result |
Type |
Proceed to |
|---|---|---|---|---|---|
|
E69-2 (CANH) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
w/ Navigation System |
A |
|
w/o Navigation System |
B |
||||
|
E69-13 (CANL) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
w/ Navigation System |
A |
|
w/o Navigation System |
B |
||||
|
E69-2 (CANH) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
- |
C |
|
E69-13 (CANL) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
- |
C |
|
|
18. |
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
|
Tester Connection |
Switch Condition |
Measured Resistance |
Proceed to |
|---|---|---|---|
|
E69-5 (CANH) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E69-16 (CANL) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E69-5 (CANH) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
E69-16 (CANL) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
|
19. |
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
|
Tester Connection |
Switch Condition |
Measured Resistance |
Proceed to |
|---|---|---|---|
|
E69-3 (CANH) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E69-14 (CANL) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E69-3 (CANH) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
E69-14 (CANL) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
|
20. |
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
|
Tester Connection |
Switch Condition |
Measured Resistance |
Proceed to |
|---|---|---|---|
|
E75-1 (CANH) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E75-12 (CANL) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E75-1 (CANH) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
E75-12 (CANL) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
|
21. |
CONNECT CONNECTOR |
(a) Reconnect the E69 No. 2 junction connector connector.
|
|
22. |
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.
|
|
|
23. |
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.
|
|
|
24. |
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
|
Tester Connection |
Switch Condition |
Measured Resistance |
Proceed to |
|---|---|---|---|
|
E75-4 (CANH) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E75-15 (CANL) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E75-4 (CANH) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
E75-15 (CANL) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
|
25. |
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (COMBINATION METER) |
|
|
(a) Disconnect the E77 combination meter connector. |
(b) Measure the resistance according to the value(s) in the table below.
Result
|
Tester Connection |
Switch Condition |
Measured Resistance |
Proceed to |
|---|---|---|---|
|
E75-3 (CANH) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E75-14 (CANL) - E22-16 (BAT) |
Engine switch off |
1 Ω or higher |
OK |
|
E75-3 (CANH) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
E75-14 (CANL) - E22-16 (BAT) |
Engine switch off |
Below 1 Ω |
NG |
|
|
|