U1024

U1024 CAN COMM CIRCUIT





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. ECM and
VVEL control module are connected with two communication lines (CAN H line and CAN L line) and transmit/receive data. ECM shares information and links with the VVEL control module during operation.




DTC Logic

DTC DETECTION LOGIC

NOTE:
If DTC U1024 is displayed with DTC P0607, first perform the trouble diagnosis for DTC P0607. P0607.






DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10 V at idle.
- GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 3 seconds.
2. Check DTC.
Is DTC detected?
YES - Go to SEE Diagnosis Procedure.
NO - INSPECTION END




Diagnosis Procedure
1.CHECK VVEL CAN COMMUNICATION CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect VVEL control module harness connector.
4. Check the continuity between ECM harness connector and VVEL control module harness connector.





5. Also check harness for short to ground and power.
Is the inspection result normal?
YES - GO TO 3.
NO - GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
- Harness connector E3, F1
- Harness for open or short between ECM and VVEL control module
- Harness for open, short to ground or short to power in harness or connectors.
3.CHECK INTERMITTENT INCIDENT
Intermittent Incident.
Is the inspection result normal?
YES - GO TO 4.
NO - Repair or replace.
4.REPLACE VVEL CONTROL MODULE
1. Replace VVEL control module. Engine Control System.
2. Go to Special Repair Requirement.
- GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Erase DTC.
4. Perform DTC Confirmation Procedure.
See SEE DTC Logic.
Is the DTC U1024 displayed again?
YES - GO TO 6.
NO - INSPECTION END
6.REPLACE ECM
1. Replace ECM.
2. Go to Special Repair Requirement.
- INSPECTION END