What is the reason for not receiving the engine ECU message?
2 Answers
Not receiving the engine ECU message indicates that the vehicle control unit (VCU) cannot receive signals sent by the engine control unit (ECU). Generally, this is due to an open circuit between the ECU and VCU. Similar faults such as CAN message timeouts also belong to open circuit issues. When the engine ECU message is not received, it is necessary to reconnect the connectors. If required, the vehicle control unit or engine control unit may need replacement. Functions of the ECU: Self-diagnostic function. The ECU typically has fault self-diagnosis and protection functions. When a system failure occurs, it can automatically record fault codes in RAM and implement protective measures by reading substitute programs from the inherent programs to maintain engine operation. Meanwhile, these fault messages will be displayed on the dashboard and remain illuminated, allowing the owner to promptly identify the issue and drive the vehicle to a repair shop. Adaptive function. Under normal circumstances, RAM continuously records the vehicle's driving data, serving as the ECU's learning program to provide optimal control states tailored to the owner's driving habits. This program is also called the adaptive program. Composition of the ECU: Similar to a regular computer, the ECU consists of a microcontroller (MCU), memory (ROM, RAM), input/output interfaces (I/O), analog-to-digital converters (A/D), as well as shaping, driving, and other large-scale integrated circuits.
I've encountered similar situations before while driving, where the engine data suddenly stopped transmitting, which was quite annoying. Most likely, it's due to loose wiring connections or oxidized connectors causing poor contact. Over time, dust buildup can easily lead to this issue. Insufficient battery power or unstable voltage can also be the culprit—if the vehicle's ECU loses power, it naturally can't send signals. Remember to check the fuse box to see if the ECU-related fuse has blown; replacing it with a new one should do the trick. CAN bus communication failure is another common cause, such as worn, broken, or short-circuited wiring, which requires scanning for error codes with a diagnostic tool. Additionally, software bugs might cause the ECU to crash, and restarting the vehicle can sometimes temporarily resolve the issue. It's best not to tinker with it yourself, especially if you notice it while driving—pull over first to avoid safety hazards and get the vehicle's telematics system checked at a repair shop as soon as possible. Regularly cleaning the wiring harness can help prevent such problems.
