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 malfunction 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 independently). 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 | Trouble diagnosis name | DTC detection condition | Possible causes |
U0300 |
Internal Control Module Software Incompatibility | When the ignition switch is ON, the data length transmitted from each control unit is shorter than the specified length and the status continues for 2 seconds or more. | Control unit other than TCM |
DTC CONFIRMATION PROCEDURE
1.PREPARATION BEFORE WORK
If another "DTC CONFIRMATION PROCEDURE" occurs just before, turn ignition switch OFF and wait for at least 10 seconds, then perform the next test.
>> GO TO 2.
2.CHECK DTC DETECTION
With CONSULT
Is "U0300" detected?
YES >> Go to TM "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
1.CONTROL UNIT CHECK
Check the number of control units replaced before "U0300" is detected.
Is one control unit replaced?
YES >> The specification of the control unit replaced may be incorrect. Check the part number and the specification.
NO >> GO TO 2.
2.CONTROL UNIT CHECK
With CONSULT
Is "U0300"detected?
YES >> Turn OFF the ignition switch and check other control units in the same manner.
NO >> The specification of the control unit removed may be incorrect. Check the part number and the specification.