Lexus ES: Open in Bus 3 Main Bus Line
DESCRIPTION
There may be an open circuit in one of the CAN main bus lines when the resistance between terminals 6 (CA3H) and 21 (CA3L) of the central gateway ECU (network gateway ECU) is 70 Ω or higher.
| Symptom | Trouble Area |
|---|---|
| Resistance between terminals 6 (CA3H) and 21 (CA3L) 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. 4 CAN JUNCTION CONNECTOR) |
(a) Disconnect the cable from the negative (-) auxiliary battery terminal.
(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 |
|---|---|---|
| G98-9 (CANH) - G98-20 (CANL) | Cable disconnected from negative (-) auxiliary battery terminal | 108 to 132 Ω |
| G98-11 (CANH) - G98-22 (CANL) | Cable disconnected from negative (-) auxiliary battery terminal | 108 to 132 Ω |
| OK | .gif) | REPLACE NO. 4 CAN JUNCTION CONNECTOR |
|
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| 2. | CHECK FOR OPEN IN CAN MAIN BUS LINES (CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) - NO. 4 CAN JUNCTION CONNECTOR) |
(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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Inspection
INSPECTION CAUTION / NOTICE / HINT NOTICE:
Make sure the contact surface of the cam timing control motor with EDU assembly (the surface that contacts the No. 2 timing gear cover assembly) is free of foreign matter.
If the cam timing control motor with EDU assembly has been struck or dropped, re
