| DTC Code | DTC Name |
|---|---|
| U1104 | Lost Communication with Driving Support ECU |
DESCRIPTION
The ECM and driving support ECU communicate with each other via the CAN communication line.
If there is a problem in this communication, the ECM stores the DTC.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| U1104 | No communication between ECM and driving support ECU (1 trip detection logic) |
|
INSPECTION PROCEDURE
Go to CAN communication system for troubleshooting Click here.
Tech Tips
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.
Note
When replacing the ECM, the ECM needs Registration and Initialization Click here.