Lost Communication With Gateway Module
NETWORKING: CAN COMMUNICATION SYSTEM: U1002: Lost Communication with Gateway Module (Parking Assist Bus)
U1002 - Lost Communication with Gateway Module (Parking Assist Bus)
DESCRIPTION
The driving support ECU will store this DTC when no signals can be received from the ECUs that have been memorized as those that are connected to the parking assist bus.
HINT
The diagnosis procedure is for when DTC U1002 is output by the driving support ECU (Techstream display: Pre-Collision2).
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
* Turn the power switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.
* Turn the power switch off before inspecting CAN bus wires for a ground short.
* After the power switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.
* Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power switch, any other switches or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.
HINT
* 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
1. CHECK CAN BUS WIRE
(a) Turn the power switch off.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
(c) Disconnect the cable from the negative (-) battery terminal.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Result:
B -- CHECK FOR OPEN IN CAN BUS WIRE (DRIVING SUPPORT ECU)
C -- CHECK FOR SHORT IN CAN BUS WIRES (DRIVING SUPPORT ECU)
D -- CHECK CAN BUS WIRE (CAN NO. 5 J/C)
A -- Continue to next step.
2. CHECK CAN BUS BRANCH WIRE (LANE RECOGNITION CAMERA SENSOR)
(a) Check for a lane recognition camera sensor communication malfunction Lane-Keeping Assist System.
NG -- REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR WIRE OR CONNECTOR
OK -- REPLACE DRIVING SUPPORT ECU Removal
3. CHECK FOR OPEN IN CAN BUS WIRE (DRIVING SUPPORT ECU)
(a) Disconnect the driving support ECU connector.
Text in Illustration
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- CHECK FOR OPEN IN CAN BUS WIRE (MILLIMETER WAVE RADAR SENSOR)
OK -- REPLACE DRIVING SUPPORT ECU Removal
4. CHECK FOR OPEN IN CAN BUS WIRE (MILLIMETER WAVE RADAR SENSOR)
(a) Reconnect the driving support ECU connector.
(b) Disconnect the millimeter wave radar sensor connector.
Text in Illustration
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- CHECK FOR OPEN IN CAN BUS WIRE (CAN NO. 5 J/C)
OK -- REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Removal
5. CHECK FOR OPEN IN CAN BUS WIRE (CAN NO. 5 J/C)
(a) Reconnect the millimeter wave radar sensor connector.
(b) Disconnect the CAN No. 5 junction connector.
Text in Illustration
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Result:
B -- REPAIR OR REPLACE CAN BUS MAIN WIRE (CAN NO. 5 J/C - DRIVING SUPPORT ECU)
C -- REPAIR OR REPLACE CAN BUS MAIN WIRE (CAN NO. 5 J/C - MILLIMETER WAVE RADAR SENSOR)
A -- REPLACE CAN NO. 5 JUNCTION CONNECTOR
6. CHECK FOR SHORT IN CAN BUS WIRES (DRIVING SUPPORT ECU)
(a) Disconnect the driving support ECU connector.
Text in Illustration
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- CHECK FOR SHORT IN CAN BUS WIRES (MILLIMETER WAVE RADAR SENSOR)
OK -- REPLACE DRIVING SUPPORT ECU Removal
7. CHECK FOR SHORT IN CAN BUS WIRES (MILLIMETER WAVE RADAR SENSOR)
(a) Reconnect the driving support ECU connector.
(b) Disconnect the millimeter wave radar sensor connector.
Text in Illustration
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 5 J/C MAIN WIRE)
OK -- Continue to next step.
8. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 5 J/C MAIN WIRE)
(a) Reconnect the millimeter wave radar sensor connector.
(b) Disconnect the CAN No. 5 junction connector.
Text in Illustration
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Result:
B -- REPAIR OR REPLACE CAN BUS MAIN WIRE (CAN NO. 5 J/C - DRIVING SUPPORT ECU)
C -- REPAIR OR REPLACE CAN BUS MAIN WIRE (CAN NO. 5 J/C - MILLIMETER WAVE RADAR SENSOR)
A -- Continue to next step.
9. CHECK FOR SHORT IN CAN BUS WIRES (LANE RECOGNITION CAMERA SENSOR BRANCH WIRE)
(a) Disconnect the lane recognition camera sensor connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPAIR OR REPLACE CAN BUS WIRE (LANE RECOGNITION CAMERA SENSOR BRANCH WIRE)
OK -- Continue to next step.
10. CHECK CAN BUS WIRE (LANE RECOGNITION CAMERA SENSOR)
(a) Reconnect the CAN No. 5 junction connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NOTICE:
* The resistance must be measured after the CAN No. 5 junction connector is reconnected.
* The resistance must be measured after the lane recognition camera sensor connector is disconnected.
NG -- REPLACE CAN NO. 5 JUNCTION CONNECTOR
OK -- REPLACE LANE RECOGNITION CAMERA SENSOR Removal
11. CHECK CAN BUS WIRE (CAN NO. 5 J/C)
(a) Disconnect the CAN No. 5 junction connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
HINT
* It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN Bus Wire inspection.
* Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.
Text in Illustration
NG -- CHECK CAN BUS WIRE (ECU, SENSOR)
OK -- REPLACE CAN NO. 5 JUNCTION CONNECTOR
12. CHECK CAN BUS WIRE (ECU, SENSOR)
(a) Disconnect the ECU or sensor connected to the CAN bus wire that is shorted to B+ or shorted to GND.
HINT
If the ECU or sensor has multiple connectors, disconnect the connector that includes the CAN bus wires. To determine the ECU or sensor that is connected to shorted bus wire, refer to Terminals of ECU tables CAN Communication System.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
HINT
* It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.
* If the resistance changes to normal when the connector is disconnected from the ECU, there may be a short in the ECU.
Text in Illustration
NG -- REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR WIRE OR CONNECTOR
OK -- REPLACE CORRESPONDING ECU