Lexus ES: Open in Bus 2 Main Bus Line
DESCRIPTION
There may be an open circuit in one of the CAN main bus lines when the resistance between terminals 18 (CA4H) and 17 (CA4L) of the central gateway ECU (network gateway ECU) is 70 Ω or higher.
| Symptom | Trouble Area |
|---|---|
| Resistance between terminals 18 (CA4H) and 17 (CA4L) of the central gateway ECU (network gateway ECU) is 70 Ω or higher. |
|
This malfunction is not related to the lines of a CAN branch or to ECUs or sensors connected to a CAN branch.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
NOTICE:
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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 power 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
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After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary 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 power switch on (IG) 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.
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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 OPEN IN CAN MAIN BUS LINES (NO. 2 JUNCTION CONNECTOR) |
(a) Disconnect the cable from the negative (-) auxiliary battery terminal.
(b) Disconnect the A71 No. 2 junction connector.
(c) Measure the resistance according to the value(s) in the table below.
| *a | Front view of wire harness connector (to No. 2 Junction Connector) | *b | to No. 4 CAN Junction Connector |
| *c | to ECM | - | - |
Standard Resistance:
| Tester Connection | Condition | Specified Condition | Connected to |
|---|---|---|---|
| A71-8 (CANH) - A71-19 (CANL) | Cable disconnected from negative (-) auxiliary battery terminal | 108 to 132 Ω | No. 4 CAN junction connector |
| A71-11 (CANH) - A71-22 (CANL) | Cable disconnected from negative (-) auxiliary 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 JUNCTION CONNECTOR |
| C | | GO TO STEP 3 |
|
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| 2. | CHECK FOR OPEN IN CAN MAIN BUS LINES (ECM) |
(a) Reconnect the A71 No. 2 junction connector.
(b) Disconnect the A26 ECM connector.
| (c) Measure the resistance according to the value(s) in the table below. Standard Resistance:
|
|
| OK | | REPLACE ECM |
| NG | | REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (ECM - NO. 2 JUNCTION CONNECTOR) |
| 3. | CHECK FOR OPEN IN CAN MAIN BUS LINES (NO. 4 CAN JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR) |
(a) Reconnect the A71 No. 2 junction connector.
(b) Disconnect the G99 No. 4 CAN junction connector.
(c) 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 No. 2 Junction Connector |
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| G99-11 (CANH) - G99-22 (CANL) | Cable disconnected from negative (-) auxiliary battery terminal | 108 to 132 Ω |
| NG | | REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 4 CAN JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR) |
|
| 4. | CHECK FOR OPEN IN CAN MAIN BUS LINES (NO. 4 CAN JUNCTION CONNECTOR) |
(a) Reconnect the G99 No. 4 CAN junction connector.
(b) Disconnect the G98 No. 4 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. 4 CAN Junction Connector) | *b | to Central Gateway ECU (Network Gateway ECU) |
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| G98-1 (CANH) - G98-12 (CANL) | Cable disconnected from negative (-) auxiliary battery terminal | 108 to 132 Ω |
| OK | | REPLACE NO. 4 CAN JUNCTION CONNECTOR |
|
| 5. | CHECK FOR OPEN IN CAN MAIN BUS LINES (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)) |
(a) Reconnect the G98 No. 4 CAN junction connector.
(b) Disconnect the G66 central gateway ECU (network gateway ECU) connector.
| (c) Measure the resistance according to the value(s) in the table below. Standard Resistance:
|
|
| OK | | REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) |
| NG | | REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) - NO. 4 CAN JUNCTION CONNECTOR) |
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SEE MORE:
Inspection
INSPECTION PROCEDURE 1. INSPECT FRONT DRIVE SHAFT ASSEMBLY (a) Check that there is no excessive play in the radial direction of the outboard joint. (b) Check that the inboard joint slides smoothly in the thrust direction. (c) Check that there is no excessive play in the radial directi
Data List / Active Test
DATA LIST / ACTIVE TEST DATA LIST NOTICE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not. (a) Connect the Techstream to the DLC3. (b) Turn the engine switch on (IG). (c)
