DESCRIPTION
There may be a short circuit between one of the CAN bus lines and +B when there is no resistance between terminal 6 (CA3H) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3, or terminal 21 (CA3L) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3.
Symptom | Trouble Area |
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There is no resistance between terminal 6 (CA3H) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3, or terminal 21 (CA3L) of the central gateway ECU (network gateway ECU) and terminal 16 (BAT) of the DLC3. |
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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.
Some parts must be initialized and set when replacing or removing and installing parts.
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.
The following malfunctions may occur if a radio receiver assembly from another vehicle is installed to this vehicle. Therefore, when replacing the radio receiver assembly, be sure to replace it with new one.
Communication malfunction DTC is output
Does not operate normally
Tech Tips
Operating the engine switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.
Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.
PROCEDURE
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 9 CAN JUNCTION CONNECTOR)
Disconnect the cable to the negative (-) battery terminal.
Disconnect the No. 9 CAN junction connector.
*a | Front view of wire harness connector (to No. 9 CAN Junction Connector) |
*b | to Central Gateway ECU (Network Gateway ECU) |
*c | to Radio Receiver Assembly | *d | to Telematics Transceiver (w/ Telematics Transceiver) |
*e | to Bus Buffer ECU (w/ Bus Buffer ECU) | *f | to Central Gateway ECU (Network Gateway ECU) |
*g | Front view of DLC3 | - | - |
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||||||||||||||||||||||
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*2: w/ Bus Buffer ECU |
Result | ||||||||
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|
A |
REPLACE NO. 9 CAN JUNCTION CONNECTOR |
C |
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECU, SENSOR) Click here |
B |
CONNECT CONNECTOR
Reconnect the I166 No. 9 CAN junction connector.
Result | ||
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NEXT |
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 9 CAN JUNCTION CONNECTOR)
*a | Front view of wire harness connector (to Central Gateway ECU [Network Gateway ECU]) |
*b | Front view of DLC3 |
Disconnect the central gateway ECU (network gateway ECU) connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||
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Result | |||
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OK |
REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) for LHD: Click here |
NG |
REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 9 CAN JUNCTION CONNECTOR) |
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECU, SENSOR)
*a | Component with harness connected (Central Gateway ECU [Network Gateway ECU]) |
*b | Front view of DLC3 |
Reconnect all wire harness connectors.
Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the bus line shorted to +B is connected.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||
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Tech Tips
If the resistance changes to 6 kΩ or higher 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 to +B in the wire harness and repair or replace the wire harness or connector if necessary.
Result | |||
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OK |
REPLACE ECU OR SENSOR |
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |