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 No. | CONSULT screen terms (Trouble diagnosis content) | DTC detecting condition | Possible cause |
U1001 | CAN COMM CIRCUIT (CAN communication circuit) | When ECM is not transmitting or receiving CAN communication signal other than OBD (emission related diagnosis) for 2 seconds or more. | Harness or connectors (CAN communication line is open or shorted) |
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
Is 1st trip DTC detected? YES >> Proceed to EC-169, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
Perform the trouble diagnosis for CAN communication system. Refer to LAN-16, "Trouble Diagnosis Flow Chart".
B2268 water temp
Description
The engine coolant temperature signal is transmitted from ecm to the
combination meter via can communication.
Dtc logic
Dtc detection logic
Dtc
Consult
Detection condition
Probable malfunction location
B2268
Water temp meter
[b2268]
Ecm continuous ...
Can communication circuit
Diagnosis procedure
1.Connector inspection
Turn the ignition switch off.
Disconnect the battery cable from the negative terminal.
Disconnect all the unit connectors on CAN communication system.
Check terminals and connectors for damage, bend and loose connection.
Is the inspection resu ...
Three Way Catalyst
If a large amount of unburned fuel flows into the catalyst, the catalyst
temperature will be excessively high. To
prevent this, follow the instructions.
Use unleaded gasoline only. Leaded gasoline will seriously damage the
three way catalyst.
When checking for ignition spark or measuring ...