| DTC Code | DTC Name |
|---|---|
| U1002 | Lost Communication with Gateway Module (Sensor Bus) |
DESCRIPTION
The driving support ECU assembly will store this DTC when no signals can be received from the ECUs that have been memorized as those that are connected to sub bus 13.
When the driving support ECU assembly receives a response signal from the ECUs connected to sub bus 13, the driving support ECU assembly recognizes and memorizes that the ECU is connected to sub bus 13. Based on this memorized data, the driving support ECU assembly monitors for malfunctions in the ECUs connected to sub bus 13 when communicating with those ECUs. If the driving support ECU assembly cannot receive response signals from the ECUs that have been memorized as those connected to sub bus 13, the driving support ECU assembly determines that a malfunction exists.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| U1002 | The driving support ECU assembly cannot receive signals from all ECUs that have been memorized as those connected to sub bus 13. |
|
*1: w/ Lane departure alert system
*2: for LHD
Tech Tips
The diagnosis procedure is for when DTC U1002 is output by the driving support ECU assembly (GTS display: Pre-Crash 2).
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Note
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, 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.
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 Click here.
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.
After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.
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 power switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
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
RECONFIRM DTC OUTPUT
Reconfirm DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here |
| A |
|
CHECK VEHICLE TYPE
Check vehicle type.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
CHECK SUB BUS 13 Click here |
| A |
|
CHECK SUB BUS 13
Turn the power switch off.
Disconnect the cable from the negative (-) auxiliary battery terminal.
| *a | Component with harness connected (Driving Support ECU Assembly) |
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| B |
|
CHECK FOR POWER SOURCE CIRCUIT (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) Click here |
| C |
|
CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (DRIVING SUPPORT ECU ASSEMBLY) Click here |
| D |
|
CHECK FOR SHORT IN SUB BUS 13 LINES (DRIVING SUPPORT ECU ASSEMBLY) Click here |
| E |
|
CHECK FOR SHORT IN SUB BUS 13 LINE (DRIVING SUPPORT ECU ASSEMBLY) Click here |
| A |
|
RECONFIRM DTC OUTPUT
Reconnect the cable to the negative (-) auxiliary battery terminal.
Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Clear the DTCs.
Turn the power switch off.
Turn the power switch on (IG) and recheck for DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| A |
|
REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here |
| B |
|
GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here |
CHECK FOR POWER SOURCE CIRCUIT (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
Check the millimeter wave radar sensor assembly power source circuit Click here.
| NG |
|
REPAIR OR REPLACE POWER SOURCE CIRCUIT (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) |
| OK |
|
CHECK FOR DTC OUTPUT
Reconnect the A55 millimeter wave radar sensor assembly connector.
Reconnect the cable to the negative (-) auxiliary battery terminal.
Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Clear the DTCs.
Turn the power switch off.
Turn the power switch on (IG).
Turn the GTS on.
Check for DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
GO TO SYMPTOM SIMULATION Click here |
| A |
|
REPLACE DRIVING SUPPORT ECU ASSEMBLY
Replace the driving support ECU assembly Click here.
| NEXT |
|
CHECK FOR DTC OUTPUT
Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Clear the DTCs.
Turn the power switch off.
Turn the power switch on (IG) .
Turn the GTS on.
Check for DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| A |
|
END |
| B |
|
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here |
CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (DRIVING SUPPORT ECU ASSEMBLY)
| *a | Front view of wire harness connector (to Driving Support ECU Assembly) |
Disconnect the H75 driving support ECU assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| OK |
|
REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here |
| NG |
|
CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (CAN NO. 3 J/C)
Reconnect the H75 driving support ECU assembly connector.
| *a | Front view of wire harness connector (to CAN No. 3 Junction Connector) |
| *b | to Driving Support ECU Assembly |
| *c | to Millimeter Wave Radar Sensor Assembly |
Disconnect the T13 CAN No. 3 junction connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| A |
|
REPLACE CAN NO. 3 JUNCTION CONNECTOR |
| B |
|
REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - DRIVING SUPPORT ECU ASSEMBLY) |
| C |
|
CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
Reconnect the T13 CAN No. 3 junction connector.
| *a | Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly ) |
Disconnect the A55 millimeter wave radar sensor assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| OK |
|
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - MILLIMETER WAVE RADAR SENSOR ASSEMBLY) |
CHECK FOR SHORT IN SUB BUS 13 LINES (DRIVING SUPPORT ECU ASSEMBLY)
| *a | Front view of wire harness connector (to Driving Support ECU Assembly) |
Disconnect the H75 driving support ECU assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| OK |
|
REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here |
| NG |
|
CHECK FOR SHORT IN SUB BUS 13 LINES (CAN NO. 3 J/C)
Reconnect the H75 driving support ECU assembly connector.
| *a | Front view of wire harness connector (to CAN No. 3 Junction Connector) |
| *b | to Driving Support ECU Assembly |
| *c | to Millimeter Wave Radar Sensor Assembly |
| *d | to Lane Departure Warning Camera* |
Disconnect the T13 CAN No. 3 junction connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
*: w/ Lane departure alert system
*: w/ Lane departure alert system
| Result | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
| A |
|
REPLACE CAN NO. 3 JUNCTION CONNECTOR |
| B |
|
REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - DRIVING SUPPORT ECU ASSEMBLY) |
| D |
|
CHECK FOR SHORT IN SUB BUS 13 LINES (LANE DEPARTURE WARNING CAMERA) Click here |
| C |
|
CHECK FOR SHORT IN SUB BUS 13 LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
Reconnect the T13 CAN No. 3 junction connector.
| *a | Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly ) |
Disconnect the A55 millimeter wave radar sensor assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| OK |
|
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - MILLIMETER WAVE RADAR SENSOR ASSEMBLY) |
CHECK FOR SHORT IN SUB BUS 13 LINES (LANE DEPARTURE WARNING CAMERA)
Reconnect the T13 CAN No. 3 junction connector.
| *a | Front view of wire harness connector (to Lane Departure Warning Camera) |
Disconnect the T12 lane departure warning camera connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| OK |
|
REPLACE LANE DEPARTURE WARNING CAMERA Click here |
| NG |
|
REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CAN NO. 3 J/C - LANE DEPARTURE WARNING CAMERA) |
CHECK FOR SHORT IN SUB BUS 13 LINE (DRIVING SUPPORT ECU ASSEMBLY)
Disconnect the H75 driving support ECU assembly connector.
| *a | Front view of wire harness connector (to Driving Support ECU Assembly) |
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Tech Tips
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 13 inspection.
Find the necessary inspection from the Result column that matches the result in the Specified Condition column from the Check Sub Bus 13 inspection.
| OK |
|
REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here |
| NG |
|
CHECK FOR SHORT IN SUB BUS 13 LINE (CAN NO. 3 J/C)
Disconnect the T13 CAN No. 3 junction connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
*: w/ Lane departure alert system
| *1 | DLC3 | - | - |
| *a | Front view of wire harness connector (to CAN No. 3 Junction Connector) |
*b | to Driving Support ECU Assembly |
| *c | to Millimeter Wave Radar Sensor Assembly | *d | to Lane Departure Warning Camera* |
*: w/ Lane departure alert system
Tech Tips
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 13 inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 13 inspection.
| Result | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
| A |
|
REPLACE CAN NO. 3 JUNCTION CONNECTOR |
| B |
|
REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - DRIVING SUPPORT ECU ASSEMBLY) |
| D |
|
CHECK FOR SHORT IN SUB BUS 13 LINE (LANE DEPARTURE WARNING CAMERA) Click here |
| C |
|
CHECK FOR SHORT IN SUB BUS 13 LINE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
Disconnect the A55 millimeter wave radar sensor assembly connector.
| *1 | DLC3 |
| *a | Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly) |
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Tech Tips
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 13 inspection.
Find the necessary inspection from the Result column that matches the result in the Specified Condition column from the Check Sub Bus 13 inspection.
| OK |
|
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - MILLIMETER WAVE RADAR SENSOR ASSEMBLY) |
CHECK FOR SHORT IN SUB BUS 13 LINE (LANE DEPARTURE WARNING CAMERA)
| *1 | DLC3 |
| *a | Front view of wire harness connector (to Lane Departure Warning Camera) |
Disconnect the T12 lane departure warning camera connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Tech Tips
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 13 inspection.
Find the necessary inspection from the Result column that matches the result in the Specified Condition column from the Check Sub Bus 13 inspection.
| OK |
|
REPLACE LANE DEPARTURE WARNING CAMERA Click here |
| NG |
|
REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CAN NO. 3 J/C - LANE DEPARTURE WARNING CAMERA) |
CHECK SUB BUS 13
Turn the power switch off.
Disconnect the cable from the negative (-) auxiliary battery terminal.
| *a | Component with harness connected (Driving Support ECU Assembly) |
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
| B |
|
CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (DRIVING SUPPORT ECU ASSEMBLY) Click here |
| C |
|
CHECK FOR SHORT IN SUB BUS 13 LINES (DRIVING SUPPORT ECU ASSEMBLY) Click here |
| D |
|
CHECK FOR SHORT IN SUB BUS 13 LINE (DRIVING SUPPORT ECU ASSEMBLY) Click here |
| A |
|
CHECK FOR POWER SOURCE CIRCUIT (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
Check the millimeter wave radar sensor assembly power source circuit Click here.
| NG |
|
REPAIR OR REPLACE POWER SOURCE CIRCUIT (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) |
| OK |
|
CHECK FOR DTC OUTPUT
Reconnect the cable to the negative (-) auxiliary battery terminal.
Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Clear the DTCs.
Turn the power switch off.
Turn the power switch on (IG).
Turn the GTS on.
Check for DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
GO TO SYMPTOM SIMULATION Click here |
| A |
|
REPLACE DRIVING SUPPORT ECU ASSEMBLY
Replace the driving support ECU assembly Click here.
| NEXT |
|
CHECK FOR DTC OUTPUT
Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Check for DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| A |
|
END |
| B |
|
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here |
CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (DRIVING SUPPORT ECU ASSEMBLY)
| *a | Front view of wire harness connector (to Driving Support ECU Assembly) |
Disconnect the H75 driving support ECU assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| OK |
|
REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here |
| NG |
|
CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
Reconnect the H75 driving support ECU assembly connector.
| *a | Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly ) |
Disconnect the A55 millimeter wave radar sensor assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| OK |
|
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY) |
CHECK FOR SHORT IN SUB BUS 13 LINES (DRIVING SUPPORT ECU ASSEMBLY)
| *a | Front view of wire harness connector (to Driving Support ECU Assembly) |
Disconnect the H75 driving support ECU assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| OK |
|
REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here |
| NG |
|
CHECK FOR SHORT IN SUB BUS 13 LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
Reconnect the H75 driving support ECU assembly connector.
| *a | Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly ) |
Disconnect the A55 millimeter wave radar sensor assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| OK |
|
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY) |
CHECK FOR SHORT IN SUB BUS 13 LINE (DRIVING SUPPORT ECU ASSEMBLY)
Disconnect the H75 driving support ECU assembly connector.
| *a | Front view of wire harness connector (to Driving Support ECU Assembly) |
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Tech Tips
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 13 inspection.
Find the necessary inspection from the Result column that matches the result in the Specified Condition column from the Check Sub Bus 13 inspection.
| OK |
|
REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here |
| NG |
|
CHECK FOR SHORT IN SUB BUS 13 LINE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
Disconnect the A55 millimeter wave radar sensor assembly connector.
| *1 | DLC3 |
| *a | Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly) |
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Tech Tips
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 13 inspection.
Find the necessary inspection from the Result column that matches the result in the Specified Condition column from the Check Sub Bus 13 inspection.
| OK |
|
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY) |