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 Code | DTC Detection Condition | Trouble Area |
---|---|---|
U1002 | Driving support ECU assembly cannot receive signals from all ECUs that have been memorized as those connected to sub bus 13. |
|
*1: w/ Driver Monitor Camera
*2: w/ Lane-keeping Assist System
*3: w/ Night View System
For vehicles with a dynamic radar cruise control system.
WIRING DIAGRAM
INSPECTION PROCEDURE
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.
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 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 notice before proceeding with work Click here.
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 at least 1.47 seconds.
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
CHECK SUB BUS 13
*a | Component with harness connected (No. 12 Junction Connector) |
*b | Front view of DLC3 |
Disconnect the cable from the negative (-) auxiliary battery terminal.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Result | Proceed to |
---|---|
OK | A |
NG (Open circuit in CAN main bus line) | B |
NG (Short circuit between bus lines) | C |
NG
|
D |
B |
CHECK FOR OPEN IN CAN BUS LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) Click here |
C |
CHECK FOR SHORT IN CAN BUS LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) Click here |
D |
CHECK FOR SHORT IN CAN BUS LINE (NO. 7 JUNCTION CONNECTOR) Click here |
A |
CHECK FOR DTC OUTPUT
Clear the DTCs.
Turn the power switch off.
Turn the power switch on (IG) check for DTCs.
Result | Proceed to |
---|---|
U1002 is output from driving support ECU assembly (GTS display / Pre-Crash 2) | A |
Other DTC is output | B |
B |
GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here |
A |
REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here
CHECK FOR OPEN IN CAN BUS LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
*a | Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly) |
Disconnect the millimeter wave radar sensor assembly connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
---|---|---|---|---|---|---|
|
NG |
CHECK FOR OPEN IN CAN BUS LINES (NO. 7 JUNCTION CONNECTOR) Click here |
OK |
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here
CHECK FOR OPEN IN CAN BUS LINES (NO. 7 JUNCTION CONNECTOR)
*a | Rear view of wire harness connector (to No. 7 Junction Connector) |
*b | to No. 3 Junction Connector |
*c | to Millimeter Wave Radar Sensor Assembly |
Reconnect the millimeter wave radar sensor assembly connector.
Disconnect the wire harness connector from the No. 7 junction connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
Result | Proceed to |
---|---|
OK | A |
NG (to Millimeter wave radar sensor assembly main bus line) | B |
NG (to No. 3 junction connector main bus line) | C |
B |
REPAIR OR REPLACE CAN MAIN WIRE BUS LINE OR CONNECTOR (NO. 7 JUNCTION CONNECTOR - MILLIMETER WAVE RADAR SENSOR ASSEMBLY) |
C |
CHECK FOR OPEN IN CAN BUS LINES (NO. 3 JUNCTION CONNECTOR) Click here |
A |
REPLACE NO. 7 JUNCTION CONNECTOR
CHECK FOR OPEN IN CAN BUS LINES (NO. 3 JUNCTION CONNECTOR)
*a | Rear view of wire harness connector (to No. 3 Junction Connector) |
*b | to No. 12 Junction Connector |
*c | to No. 7 Junction Connector |
Reconnect the wire harness connector from the No. 7 junction connector.
Disconnect the wire harness connector from the No. 3 junction connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
Result | Proceed to |
---|---|
OK | A |
NG (to No. 7 junction connector main bus line) | B |
NG (to No. 12 junction connector main bus line) | C |
B |
REPAIR OR REPLACE CAN MAIN WIRE BUS LINE OR CONNECTOR (NO. 3 JUNCTION CONNECTOR - NO. 7 JUNCTION CONNECTOR) |
C |
CHECK FOR OPEN IN CAN BUS LINES (NO. 12 JUNCTION CONNECTOR) Click here |
A |
REPLACE NO. 3 JUNCTION CONNECTOR
CHECK FOR OPEN IN CAN BUS LINES (NO. 12 JUNCTION CONNECTOR)
*a | Rear view of wire harness connector (to No. 12 Junction Connector) |
Reconnect the wire harness connector from the No. 3 junction connector.
Disconnect the wire harness connector from the No. 12 junction connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
---|---|---|---|---|---|---|
|
NG |
REPAIR OR REPLACE CAN MAIN WIRE BUS LINE OR CONNECTOR (NO. 12 JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR) |
OK |
REPLACE NO. 12 JUNCTION CONNECTOR
CHECK FOR SHORT IN CAN BUS LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
*a | Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly) |
Disconnect the millimeter wave radar sensor assembly connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
---|---|---|---|---|---|---|
|
NG |
CHECK FOR SHORT IN CAN BUS LINES (NO. 7 JUNCTION CONNECTOR) Click here |
OK |
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here
CHECK FOR SHORT IN CAN BUS LINES (NO. 7 JUNCTION CONNECTOR)
*a | Rear view of wire harness connector (to No. 7 Junction Connector) |
*b | to No. 3 Junction Connector |
*c | to Driver Monitor ECU Assembly |
*d | to Driving Support ECU Assembly |
*e | to Lane Recognition Camera Sensor Assembly |
*f | to Millimeter Wave Radar Sensor Assembly |
Reconnect the millimeter wave radar sensor assembly connector.
Disconnect the wire harness connector from the No. 7 junction connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
*1: w/ Driver Monitor Camera
*2: w/ Lane-keeping Assist System
Result | Proceed to |
---|---|
OK | A |
NG (to Millimeter wave radar sensor assembly main bus line) | B |
NG (to No. 3 junction connector main bus line) | C |
NG (to Driver monitor ECU assembly branch bus line) | D |
NG (to Driving support ECU assembly branch bus line) | |
NG (to Lane recognition camera sensor assembly branch bus line) |
B |
REPAIR OR REPLACE CAN MAIN WIRE BUS LINE OR CONNECTOR (NO. 7 JUNCTION CONNECTOR - MILLIMETER WAVE RADAR SENSOR ASSEMBLY) |
C |
CHECK FOR SHORT IN CAN BUS LINES (NO. 3 JUNCTION CONNECTOR) Click here |
D |
CHECK FOR SHORT IN CAN BUS LINES (ECUS) Click here |
A |
REPLACE NO. 7 JUNCTION CONNECTOR
CHECK FOR SHORT IN CAN BUS LINES (NO. 3 JUNCTION CONNECTOR)
*a | Rear view of wire harness connector (to No. 3 Junction Connector) |
*b | to No. 1 Night View ECU |
*c | to No. 12 Junction Connector |
*d | to No. 7 Junction Connector |
Reconnect the wire harness connector from the No. 7 junction connector.
Disconnect the wire harness connector from the No. 3 junction connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
|
*: w/ Night View System
Result | Proceed to |
---|---|
OK | A |
NG (to No. 7 junction connector main bus line) | B |
NG (to No. 12 junction connector main bus line) | C |
NG (to No. 1 night view ECU branch bus line) | D |
B |
REPAIR OR REPLACE CAN MAIN WIRE BUS LINE OR CONNECTOR (NO. 3 JUNCTION CONNECTOR - NO. 7 JUNCTION CONNECTOR) |
C |
CHECK FOR SHORT IN CAN BUS LINES (NO. 12 JUNCTION CONNECTOR) Click here |
D |
CHECK FOR SHORT IN CAN BUS LINES (ECUS) Click here |
A |
REPLACE NO. 3 JUNCTION CONNECTOR
CHECK FOR SHORT IN CAN BUS LINES (NO. 12 JUNCTION CONNECTOR)
*a | Rear view of wire harness connector (to No. 12 Junction Connector) |
Reconnect the wire harness connector from the No. 3 junction connector.
Disconnect the wire harness connector from the No. 12 junction connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
---|---|---|---|---|---|---|
|
NG |
REPAIR OR REPLACE CAN MAIN WIRE BUS LINE OR CONNECTOR (NO. 12 JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR) |
OK |
REPLACE NO. 12 JUNCTION CONNECTOR
CHECK FOR SHORT IN CAN BUS LINES (ECUS)
*a | Component with harness connected (No. 12 Junction Connector) |
Reconnect all wire harness connectors (No. 3 junction connector and No. 7 junction connector).
Disconnect the connector that includes terminals CAN+ and CAN- from the ECU (or sensor) to which the short-circuited branch line is connected Click here.
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 (between 54 and 69 Ω) when the connector is disconnected from the ECU (or sensor), repair or replace the short-circuited branch line or connector.
NG |
REPAIR OR REPLACE CORRESPONDING ECU WIRE |
OK |
REPLACE CORRESPONDING ECU
CHECK FOR SHORT IN CAN BUS LINE (NO. 7 JUNCTION CONNECTOR)
Disconnect the wire harness connector from the No. 7 junction connector.
*a | Rear view of wire harness connector (to No. 7 Junction Connector) |
*b | Front view of DLC3 |
*c | to No. 3 Junction Connector | *d | to Driver Monitor ECU Assembly |
*e | to Driving Support ECU Assembly | *f | to Lane Recognition Camera Sensor Assembly |
*g | to Millimeter Wave Radar Sensor Assembly | - | - |
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
*1: w/ Driver Monitor Camera
*2: w/ Lane-keeping Assist System
Result | Proceed to |
---|---|
OK | A |
NG (to Millimeter wave radar sensor assembly main bus line) | B |
NG (to No. 3 junction connector main bus line) | C |
NG (to Driver monitor ECU assembly branch bus line) | D |
NG (to Driving support ECU assembly branch bus line) | |
NG (to Lane recognition camera sensor assembly branch bus line) |
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.
B |
CHECK FOR SHORT IN CAN BUS LINE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) Click here |
C |
CHECK FOR SHORT IN CAN BUS LINE (NO. 3 JUNCTION CONNECTOR) Click here |
D |
CHECK FOR SHORT IN CAN BUS LINE (ECUS) Click here |
A |
REPLACE NO. 7 JUNCTION CONNECTOR
CHECK FOR SHORT IN CAN BUS LINE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
*a | Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly) |
*b | Front view of DLC3 |
Reconnect the wire harness connector from the No. 7 junction connector.
Disconnect the millimeter wave radar sensor assembly 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.
NG |
REPAIR OR REPLACE CAN MAIN WIRE BUS LINE OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - NO. 7 JUNCTION CONNECTOR) |
OK |
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here
CHECK FOR SHORT IN CAN BUS LINE (NO. 3 JUNCTION CONNECTOR)
Reconnect the wire harness connector from the No. 7 junction connector.
*a | Rear view of wire harness connector (to No. 3 Junction Connector) |
*b | Front view of DLC3 |
*c | to No. 1 Night View ECU | *d | to No. 12 Junction Connector |
*e | to No. 7 Junction Connector | - | - |
Disconnect the wire harness connector from the No. 3 Junction Connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
*: w/ Night View System
Result | Proceed to |
---|---|
OK | A |
NG (to No. 7 junction connector main bus line) | B |
NG (to No. 12 junction connector main bus line) | C |
NG (to No. 1 night view ECU branch bus line) | D |
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.
B |
REPAIR OR REPLACE CAN MAIN WIRE BUS LINE OR CONNECTOR (NO. 3 JUNCTION CONNECTOR - NO. 7 JUNCTION CONNECTOR) |
C |
CHECK FOR SHORT IN CAN BUS LINE (NO. 12 JUNCTION CONNECTOR) Click here |
D |
CHECK FOR SHORT IN CAN BUS LINE (ECUS) Click here |
A |
REPLACE NO. 3 JUNCTION CONNECTOR
CHECK FOR SHORT IN CAN BUS LINE (NO. 12 JUNCTION CONNECTOR)
*a | Rear view of wire harness connector (to No. 12 Junction Connector) |
*b | Front view of DLC3 |
Reconnect the wire harness connector from the No. 3 junction connector.
Disconnect the wire harness connector from the No. 12 junction 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.
NG |
REPAIR OR REPLACE CAN MAIN WIRE BUS LINE OR CONNECTOR (NO. 12 JUNCTION CONNECTOR - NO. 3 JUNCTION CONNECTOR) |
OK |
REPLACE NO. 12 JUNCTION CONNECTOR
CHECK FOR SHORT IN CAN BUS LINE (ECUS)
*a | Component with harness connected (No. 12 Junction Connector) |
*b | Front view of DLC3 |
Reconnect all wire harness connectors (No. 3 junction connector and No. 7 junction connector).
Disconnect the connector that includes terminals CAN+ and CAN- from the ECU to which the bus line shorted to B+ or shorted to GND is connected.
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.
If the resistance becomes abnormal when an ECU connector is reconnected, there may be a short in the ECU.
NG |
REPAIR OR REPLACE CORRESPONDING ECU WIRE |
OK |
REPLACE CORRESPONDING ECU