DESCRIPTION
There may be a short circuit between the CAN main bus lines and/or CAN branch lines when the resistance between terminals 6 (CA3H) and 21 (CA3L) of the central gateway ECU (network gateway ECU) is below 54 Ω.
| Symptom | Trouble Area |
|---|---|
| Resistance between terminals 6 (CA3H) and 21 (CA3L) of the central gateway ECU (network gateway ECU) is below 54 Ω. |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Note
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.
Before measuring the resistance of the CAN bus, turn the engine 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 engine 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.
After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.
DTC check procedure: Turn the engine 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.
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.
Tech Tips
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
CHECK FOR SHORT IN CAN BUS LINES (NO. 7 CAN JUNCTION CONNECTOR)
Disconnect the cable from the negative (-) battery terminal.
Disconnect the G130, G131 and G133 No. 7 CAN junction connectors.
Measure the resistance according to the value(s) in the table below.
| *a | Rear view of wire harness connector (to No. 7 CAN junction connector) |
*b | to Central Gateway ECU (Network Gateway ECU) |
| *c | to Navigation Receiver Assembly (w/ Genuine Navigation Receiver) |
*d | to Optional Navigation Receiver (w/ Optional Navigation Receiver) |
| Standard Resistance | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
*1: w/ Genuine Navigation Receiver
*2: w/ Optional Navigation Receiver
Note
Before disconnecting the connectors, make a note of where they are connected.
Reconnect each connector to its original position.
Tech Tips
If there is a short in a CAN bus line without any CAN compatible optional devices connected to the option connector, repair or replace the CAN bus branch line or the option connector.
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| A |
|
REPLACE NO. 7 CAN JUNCTION CONNECTOR |
| C |
|
CHECK FOR SHORT IN CAN BUS LINES (ECU OR SENSOR) Click here |
| B |
|
CHECK FOR SHORT IN CAN BUS LINES (NO. 7 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))
Reconnect the G133 No. 7 CAN junction connector.
Disconnect the G116 central gateway ECU (network gateway ECU) connector.
Measure the resistance according to the value(s) in the table below.
| *a | Rear view of wire harness connector (to No. 7 CAN Junction Connector) |
*b | to Central Gateway ECU (Network Gateway ECU) |
| Standard Resistance | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Note
Before disconnecting the connectors, make a note of where they are connected.
Reconnect each connector to its original position.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) Click here |
| NG |
|
REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 7 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)) |
CHECK FOR SHORT IN CAN BUS LINES (ECU OR SENSOR)
Reconnect all wire harness connectors.
Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the short circuited branch line is connected.
| *a | Component with harness connected (Central Gateway ECU (Network Gateway ECU)) |
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
Tech Tips
If the resistance becomes normal (between 54 and 69 Ω) when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.
If the resistance does not become normal when the connector is disconnected from the ECU or sensor, check for a short in the wire harness and repair or replace the wire harness or connector if necessary.
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE ECU OR SENSOR |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |