DESCRIPTION
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| U0028 | Communication malfunction (3 trip detection logic) |
ECM |
INSPECTION PROCEDURE
Go to CAN communication system for troubleshooting (Click here).
When a DTC indicating a CAN communication system malfunction is output, repair the CAN communication system before repairing each corresponding sensor.
Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.
If the CAN communication malfunctions, there is no data output from the ECM. In this case, some of the freeze frame data is not correct and not identical to the ECM data. However the ECM data is correct.
When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing the new ECM, perform all of the initialization/registrations for the "Learning Values Write" function by following the instructions shown on the GTS display.
When replacing the ECM, the ECM needs Registration and Initialization (Click here).