Toyota Camry (XV70): Check Bus 2 Lines for Short Circuit
DESCRIPTION
There may be a short circuit between the CAN main bus lines and/or CAN branch lines when the resistance between terminals 18 (CA4H) and 17 (CA4L) of the central gateway ECU (network gateway ECU) is below 54 Ω.
|
Symptom | Trouble Area |
|---|---|
|
Resistance between terminals 18 (CA4H) and 17 (CA4L) of the central gateway ECU (network gateway ECU) is below 54 Ω. |
|
WIRING DIAGRAM
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CAUTION / NOTICE / HINT
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
NOTICE:
- Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.
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- Before measuring the resistance of the CAN bus, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
- After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.
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- After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.
DTC check procedure: Turn the ignition switch to ON and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.
- After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed as normal.
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HINT:
- Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.
- When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.
PROCEDURE
|
1. | CHECK FOR SHORT IN CAN BUS LINES (NO. 2 CAN JUNCTION CONNECTOR) |
(a) Disconnect the cable from the negative (-) battery terminal.
(b) Disconnect the A67 No. 2 CAN junction connector.
(c) Measure the resistance according to the value(s) in the table below.
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|
*a | Front view of wire harness connector (to No. 2 CAN Junction Connector) |
*b | to No. 4 CAN Junction Connector |
|
*c | to ECM |
- | - |
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition | Connected to |
|---|---|---|---|
|
A67-10 (CANH) - A67-21 (CANL) |
Cable disconnected from negative (-) battery terminal |
108 to 132 Ω | No. 4 CAN junction connector |
|
A67-11 (CANH) - A67-22 (CANL) |
Cable disconnected from negative (-) battery terminal |
108 to 132 Ω | ECM |
|
Result | Proceed to |
|---|---|
|
OK | A |
|
NG (Line to ECM) | B |
|
NG (Line to No. 4 CAN junction connector) |
C |
| A |
.gif) | REPLACE NO. 2 CAN JUNCTION CONNECTOR |
| C |
| GO TO STEP 3 |
|
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| 2. |
CHECK FOR SHORT IN CAN BUS LINES (NO. 2 CAN JUNCTION CONNECTOR - ECM) |
(a) Disconnect the A21 or A24 ECM connector.
(b) Measure the resistance according to the value(s) in the table below.
|
*a | Front view of wire harness connector (to No. 2 CAN Junction Connector) |
*b | to ECM |
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A67-11 (CANH) - A67-22 (CANL) |
Cable disconnected from negative (-) battery terminal |
1 MΩ or higher |
|
Result | Proceed to |
|---|---|
|
OK (for A25A-FKS) | A |
|
OK (for 2GR-FKS) | B |
|
NG | C |
| A |
| REPLACE ECM
|
| B |
| REPLACE ECM
|
| C |
| REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - ECM) |
| 3. |
CHECK FOR SHORT IN CAN BUS LINES (NO. 4 CAN JUNCTION CONNECTOR - NO. 2 CAN JUNCTION CONNECTOR) |
(a) Disconnect the K128 No. 4 CAN junction connector.
(b) Measure the resistance according to the value(s) in the table below.
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|
*a | Front view of wire harness connector (to No. 4 CAN Junction Connector) |
*b | to No. 2 CAN Junction Connector |
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition | Connected to |
|---|---|---|---|
|
K128-11 (CANH) - K128-22 (CANL) |
Cable disconnected from negative (-) battery terminal |
1 MΩ or higher | No. 2 CAN junction connector |
| NG | | REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 4 CAN JUNCTION CONNECTOR - NO. 2 CAN JUNCTION CONNECTOR) |
|
| 4. |
CHECK FOR SHORT IN CAN BUS LINES (NO. 4 CAN JUNCTION CONNECTOR) |
(a) Disconnect the K127 No. 4 CAN junction connector.
(b) Measure the resistance according to the value(s) in the table below.
.png)
|
*a | Front view of wire harness connector (to No. 4 CAN Junction Connector) |
*b | to Central Gateway ECU (Network Gateway ECU) |
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition | Connected to |
|---|---|---|---|
|
K127-1 (CANH) - K127-12 (CANL) |
Cable disconnected from negative (-) battery terminal |
108 to 132 Ω | Central gateway ECU (network gateway ECU) |
| OK | | REPLACE NO. 4 CAN JUNCTION CONNECTOR |
|
| 5. |
CHECK FOR SHORT IN CAN BUS LINES (NO. 4 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)) |
(a) Disconnect the K76 central gateway ECU (network gateway ECU) connector.
(b) Measure the resistance according to the value(s) in the table below.
|
*a | Front view of wire harness connector (to No. 4 CAN Junction Connector) |
*b | to Central Gateway ECU (Network Gateway ECU) |
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
K127-1 (CANH) - K127-12 (CANL) |
Cable disconnected from negative (-) battery terminal |
1 MΩ or higher |
| OK | | REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)
|
| NG | | REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 4 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)) |
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Open in Bus 3 Main Bus Line
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SEE MORE:
Indications on multi-information display - LTA (Lane Tracing
Assist)
The illustration used is intended as an example, and may differ from
the image that is actually displayed on the multi-information display.
LTA indicator
The illumination condition of the
indicator informs the driver of
the system operation status.
Illuminated in white:
LTA system is
Inspection
INSPECTION PROCEDURE 1. INSPECT VACUUM SWITCHING VALVE (for Active Control Engine Mount System)
(a) Measure the resistance.
(1) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection Condition
Specified Condition
