U1002

U1002 SYSTEM COMM (CAN)





Description
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.




DTC Logic

DTC DETECTION LOGIC






DTC CONFIRMATION PROCEDURE
1.DTC REPRODUCTION PROCEDURE
1. Turn the ignition switch ON.
2. Perform self-diagnosis for "ABS" with CONSULT-III.
Is DTC "U1002" detected?
YES - Proceed to diagnosis procedure. U1002.
NO - INSPECTION END




Diagnosis Procedure

CAUTION:
- Never apply 7.0 V or more to the measurement terminal.
- Use a tester with open terminal voltage of 7.0 V or less.
- Turn the ignition switch OFF and disconnect the battery cable from the negative terminal when checking the harness.
1.CHECK CAN DIAGNOSIS SUPPORT MONITOR
1. Select "ABS" and "CAN Diagnosis Support Monitor" in order with CONSULT-III.
2. Check malfunction history between each control unit connected to ABS actuator and electric unit (control unit).
Check the result of "PAST"?
All items are "OK"-INSPECTION END
"TRANSMIT DIAG" is other than "OK"-GO TO 2.
A control unit other than ABS actuator and electric unit (control unit) is anything other than "OK"-GO TO 3.
2.CHECK TRANSMITTING SIDE UNIT
Check the ABS actuator and electric unit (control unit) harness connector terminals No. 14 and 35 for damage or loose connection.
Is the inspection result normal?
YES - Erase self-diagnosis results. Then perform self-diagnosis for "ABS" with CONSULT-III.
NO - Recheck terminals for damage or loose connection. Precautions For Harness Repair.
3.CHECK APPLICABLE CONTROL UNIT
Check terminals of each CAN communication line harness connector for damage or loose connection.
Is the inspection result normal?
YES - Erase self-diagnosis results. Then perform self-diagnosis for applicable control unit with CONSULT-III.
NO - Recheck terminals for damage or loose connection. Precautions For Harness Repair.




Special Repair Requirement
1.ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION
Always perform the neutral position adjustment for the steering angle sensor, when replacing the ABS actuator and electric unit (control unit) or steering angle sensor and removing steering angle sensor. Special Repair Requirement
- END