CAN COMMUNICATION SYSTEM(for RHD with Central Gateway ECU), Diagnostic DTC:U1002
| 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 local bus.
-
When the driving support ECU assembly receives a response signal from the ECUs connected to local bus, the driving support ECU assembly recognizes and memorizes that the ECU is connected to local bus. Based on this memorized data, the driving support ECU assembly monitors for malfunctions in the ECUs connected to local bus 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 local bus, 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 local bus.
-
Open or short in local bus CAN main wire or connector
-
Open or short in local bus CAN branch wire or connector
-
Driving support ECU assembly
-
Millimeter wave radar sensor assembly
-
Forward recognition camera
-
No. 10 CAN junction connector
-
WIRING DIAGRAM
| *a | Driving Support ECU Assembly |
| *b | Forward Recognition Camera |
| *c | Millimeter Wave Radar Sensor Assembly |
| *d | No. 10 CAN Junction Connector |
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 ignition 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 ignition 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.
-
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
-
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 ignition 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 LOCAL BUS
-
Text in Illustration *a Component with harness connected
(Driving Support ECU Assembly)
*B Front view of DLC3 Disconnect the cable from the negative (-) battery terminal.
-
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition Resistance: Malfunction E164-8 (CA1P) - E164-9 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Below 53 Ω: Short in line E164-8 (CA1P) - E164-9 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Higher than 70 Ω: Open in CAN main bus line E164-8 (CA1P) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: +B short E164-9 (CA1N) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: +B short E164-8 (CA1P) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: Ground short E164-9 (CA1N) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: Ground short Result Result Proceed to OK A NG (Open circuit in CAN main bus wire) B NG (Short circuit between bus wire) C NG
-
Ground short
-
+B short
D -
B 
CHECK FOR OPEN IN CAN BUS MAIN WIRE (FORWARD RECOGNITION CAMERA) Click here
C
CHECK FOR SHORT IN CAN BUS WIRES (FORWARD RECOGNITION CAMERA) Click here
D
CHECK FOR SHORT IN CAN BUS WIRES (FORWARD RECOGNITION CAMERA) Click here
A 
-
-
CHECK FOR DTC OUTPUT
-
Clear the DTCs Click here.
-
Recheck for DTCs and check that no DTCs are output Click here.
OK DTC U1002 is not output.
OK 
USE SIMULATION METHOD TO CHECK Click here
NG
REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here
-
-
CHECK FOR OPEN IN CAN BUS MAIN WIRE (FORWARD RECOGNITION CAMERA)
-
Text in Illustration *a Front view of wire harness connector
(to Forward Recognition Camera)
Disconnect the forward recognition camera connector.
-
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition R20-6 (CANH) - R20-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
OK
REPLACE FORWARD RECOGNITION CAMERA Click here
NG
-
-
CONNECT CONNECTOR
-
Reconnect the R20 forward recognition camera connector.
NEXT
-
-
CHECK FOR OPEN IN CAN BUS MAIN WIRE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
-
Text in Illustration *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 Tester Connection Condition Specified Condition A72-5 (CA1P) - A72-6 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
OK
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here
NG
-
-
CONNECT CONNECTOR
-
Reconnect the A72 millimeter wave radar sensor assembly connector.
NEXT
-
-
CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 10 CAN JUNCTION CONNECTOR)
-
Disconnect the No. 10 CAN junction connector.
Text in Illustration *a Front view of wire harness connector
(to No. 10 CAN Junction Connector)
*b to Millimeter Wave Radar Sensor Assembly *c to Forward Recognition Camera - - -
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition Connect to E174-5 (CANH) - E174-15 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Millimeter wave radar sensor assembly E174-6 (CANH) - E174-16 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Forward recognition camera Result Result Proceed to OK A NG (Millimeter wave radar sensor assembly CAN main wire) B NG (Forward recognition camera CAN main wire) C
A
REPLACE NO. 10 CAN JUNCTION CONNECTOR
B
REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 10 CAN JUNCTION CONNECTOR - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
C
REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 10 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA)
-
-
CHECK FOR SHORT IN CAN BUS WIRES (FORWARD RECOGNITION CAMERA)
-
Text in Illustration *a Front view of wire harness connector
(to Forward Recognition Camera)
Disconnect the forward recognition camera connector.
-
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition R20-6 (CANH) - R20-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
OK
REPLACE FORWARD RECOGNITION CAMERA Click here
NG
-
-
CONNECT CONNECTOR
-
Reconnect the R20 forward recognition camera connector.
NEXT
-
-
CHECK FOR SHORT IN CAN BUS WIRES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
-
Text in Illustration *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 Tester Connection Condition Specified Condition A72-5 (CA1P) - A72-6 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
OK
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here
NG
-
-
CONNECT CONNECTOR
-
Reconnect the A72 millimeter wave radar sensor assembly connector.
NEXT
-
-
CHECK FOR SHORT IN CAN BUS WIRES (NO. 10 CAN JUNCTION CONNECTOR)
-
Disconnect the No. 10 CAN junction connector.
Text in Illustration *a Front view of wire harness connector
(to No. 10 CAN Junction Connector)
*b to Millimeter Wave Radar Sensor Assembly *c to Forward Recognition Camera *d to Driving Support ECU Assembly -
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition Connect to E174-5 (CANH) - E174-15 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Millimeter wave radar sensor assembly E174-6 (CANH) - E174-16 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Driving support ECU assembly E174-7 (CANH) - E174-17 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Forward recognition camera Result Result Proceed to OK A NG (Millimeter wave radar sensor assembly CAN main wire) B NG (Forward recognition camera CAN main wire) C NG (Driving support ECU assembly CAN branch wire) D
A
REPLACE NO. 10 CAN JUNCTION CONNECTOR
B
REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 10 CAN JUNCTION CONNECTOR - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
C
REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 10 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA)
D
-
-
CONNECT CONNECTOR
-
Reconnect the E174 No. 10 CAN junction connector.
NEXT
-
-
CHECK FOR SHORT IN CAN BUS WIRES (DRIVING SUPPORT ECU ASSEMBLY)
-
Text in Illustration *a Front view of wire harness connector
(to Driving Support ECU Assembly)
Disconnect the driving support ECU assembly connector.
-
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition E164-8 (CA1P) - E164-9 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
OK
REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here
NG
REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - NO. 10 CAN JUNCTION CONNECTOR)
-
-
CHECK FOR SHORT IN CAN BUS WIRES (FORWARD RECOGNITION CAMERA)
-
Text in Illustration *a Front view of wire harness connector
(to Forward Recognition Camera)
*b Front view of DLC3 Disconnect the forward recognition camera connector.
-
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition R20-6 (CANH) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher R20-12 (CANL) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher R20-6 (CANH) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher R20-12 (CANL) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
OK
REPLACE FORWARD RECOGNITION CAMERA Click here
NG
-
-
CONNECT CONNECTOR
-
Reconnect the R20 forward recognition camera connector.
NEXT
-
-
CHECK FOR SHORT IN CAN BUS WIRES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
-
Text in Illustration *a Front view of wire harness connector
(to Millimeter Wave Radar Sensor Assembly)
*b Front view of DLC3 Disconnect the millimeter wave radar sensor assembly connector.
-
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition A72-5 (CA1P) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher A72-6 (CA1N) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher A72-5 (CA1P) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher A72-6 (CA1N) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
OK
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here
NG
-
-
CONNECT CONNECTOR
-
Reconnect the A72 millimeter wave radar sensor assembly connector.
NEXT
-
-
CHECK FOR SHORT IN CAN BUS WIRES (NO. 10 CAN JUNCTION CONNECTOR)
-
Disconnect the No. 10 CAN junction connector.
Text in Illustration *a Front view of wire harness connector
(to No. 10 CAN Junction Connector)
*b Front view of DLC3 *c to Millimeter Wave Radar Sensor Assembly *d to Forward Recognition Camera *e to Driving Support ECU Assembly - - -
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition Connect to E174-5 (CANH) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Millimeter wave radar sensor assembly E174-15 (CANL) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher E174-5 (CANH) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher E174-15 (CANL) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher E174-6 (CANH) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Forward recognition camera E174-16 (CANL) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher E174-6 (CANH) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher E174-16 (CANL) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher E174-7 (CANH) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Driving support ECU assembly E174-17 (CANL) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher E174-7 (CANH) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher E174-17 (CANL) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Result Result Proceed to OK A NG (Millimeter wave radar sensor assembly CAN main wire) B NG (Forward recognition camera CAN main wire) C NG (Driving support ECU assembly CAN branch wire) D
A
REPLACE NO. 10 CAN JUNCTION CONNECTOR
B
REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 10 CAN JUNCTION CONNECTOR - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)
C
REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 10 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA)
D
-
-
CONNECT CONNECTOR
-
Reconnect the E174 No. 10 CAN junction connector.
NEXT
-
-
CHECK FOR SHORT IN CAN BUS WIRES (DRIVING SUPPORT ECU ASSEMBLY)
-
Text in Illustration *a Front view of wire harness connector
(to Driving Support ECU Assembly)
*b Front view of DLC3 Disconnect the driving support ECU assembly connector.
-
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition E164-8 (CA1P) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher E164-9 (CA1N) - E22-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher E164-8 (CA1P) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher E164-9 (CA1N) - E22-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
OK
REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here
NG
REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - NO. 10 CAN JUNCTION CONNECTOR)
-