DESCRIPTION
There may be a short circuit between one of the CAN bus wires and +B when no resistance exists between terminal 18 (CA4H) of the central gateway ECU and terminal 16 (BAT) of the DLC3, or terminal 17 (CA4L) of the central gateway ECU and terminal 16 (BAT) of the DLC3.
| Detection Item | Trouble Area |
|---|---|
| No resistance exists between terminal 18 (CA4H) of the central gateway ECU and terminal 16 (BAT) of the DLC3, or terminal 17 (CA4L) of the central gateway ECU and terminal 16 (BAT) of the DLC3. |
|
*: w/ Tire Pressure Warning System
WIRING DIAGRAM
| *a | Steering Control ECU |
| *b | Certification ECU (Smart Key ECU Assembly) |
| *c | No. 2 CAN Junction Connector |
| *d | Combination Meter Assembly |
CAUTION / NOTICE / HINT
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 Click here.
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, 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 battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work Click here.
After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed Click here.
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 (ECM - NO. 1 CAN JUNCTION CONNECTOR)
for 1VD-FTV:
| *a | Front view of wire harness connector (to ECM) |
| *b | Front view of DLC3 |
Disconnect the cable from the negative (-) battery terminal.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
for 3UR-FE:
| *a | Front view of wire harness connector (to ECM) |
| *b | Front view of DLC3 |
Disconnect the cable from the negative (-) battery terminal.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| Result | Proceed to |
|---|---|
| OK (for 1VD-FTV) | A |
| OK (for 3UR-FE) | B |
| NG | C |
| A |
|
REPLACE ECM Click here |
| B |
|
REPLACE ECM Click here |
| C |
|
CONNECT CONNECTOR
Reconnect the A86*1 or A97*2 ECM connector.
*1: for 1VD-FTV
*2: for 3UR-FE
| NEXT |
|
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (COMBINATION METER ASSEMBLY - NO. 2 CAN JUNCTION CONNECTOR)
| *a | Rear view of wire harness connector (to Combination Meter Assembly) |
| *b | Front view of DLC3 |
Disconnect the combination meter assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| OK |
|
REPLACE COMBINATION METER ASSEMBLY Click here |
| NG |
|
CONNECT CONNECTOR
Reconnect the E120 combination meter assembly connector.
| NEXT |
|
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CENTRAL GATEWAY ECU - NO. 1 CAN JUNCTION CONNECTOR)
| *a | Front view of wire harness connector (to Central Gateway ECU) |
| *b | Front view of DLC3 |
Disconnect the central gateway ECU connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| OK |
|
REPLACE CENTRAL GATEWAY ECU Click here |
| NG |
|
CONNECT CONNECTOR
Reconnect the E137 central gateway ECU connector.
| NEXT |
|
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 1 CAN JUNCTION CONNECTOR)
Disconnect the No. 1 CAN junction connector.
| *a | Front view of wire harness connector (to No. 1 CAN Junction Connector) |
*b | Front view of DLC3 |
| *c | to No. 2 CAN Junction Connector | *d | to Main Body ECU (Multiplex Network Body ECU) |
| *e | to Master Cylinder Solenoid (Skid Control ECU) | *f | to Headlight ECU Sub-assembly LH |
| *g | to Air Conditioning Amplifier Assembly | *h | to ECM |
| *i | to Central Gateway ECU | *j | to Meter Mirror Sub-assembly |
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | Proceed to |
|---|---|
| OK | A |
| NG (ECM CAN main wire) | B |
| NG (Central gateway ECU CAN branch wire) | C |
| NG (No. 2 CAN junction connector CAN main wire) | D |
| NG (ECU or sensor CAN branch wires) | E |
| A |
|
REPLACE NO. 1 CAN JUNCTION CONNECTOR |
| B |
|
REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 1 CAN JUNCTION CONNECTOR - ECM) |
| C |
|
REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (NO. 1 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU) |
| E |
|
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECU, SENSOR) Click here |
| D |
|
CONNECT CONNECTOR
Reconnect the E158 No. 1 CAN junction connector.
| NEXT |
|
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NO. 2 CAN JUNCTION CONNECTOR)
Disconnect the No. 2 CAN junction connector.
| *a | Front view of wire harness connector (to No. 2 CAN Junction Connector) |
*b | Front view of DLC3 |
| *c | to No. 1 CAN Junction Connector | *d | to 4WD Control ECU |
| *e | to Power Steering ECU Assembly | *f | to Airbag Sensor Assembly |
| *g | to Tire Pressure Warning ECU (w/ Tire Pressure Warning System) | *h | to Spiral with Sensor Cable Sub-assembly (Steering Angle Sensor) |
| *i | to Combination Meter Assembly | *j | to Certification ECU (Smart Key ECU Assembly) |
| *k | to Steering Control ECU | - | - |
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
*: w/ Tire Pressure Warning System
| Result | Proceed to |
|---|---|
| OK | A |
| NG (Combination meter assembly CAN main wire) | B |
| NG (No. 1 CAN junction connector CAN main wire) | C |
| NG (ECU or sensor CAN branch wires) | D |
| A |
|
REPLACE NO. 2 CAN JUNCTION CONNECTOR |
| B |
|
REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - COMBINATION METER ASSEMBLY) |
| C |
|
REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - NO. 1 CAN JUNCTION CONNECTOR) |
| D |
|
CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECU, SENSOR)
| *a | Component with harness connected (Central Gateway ECU) |
| *b | Front view of DLC3 |
Reconnect the CAN junction connector.
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 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
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.
| OK |
|
REPLACE CORRESPONDING ECU OR SENSOR |
| NG |
|
REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR CAN BRANCH WIRES OR CONNECTOR |