Can anybody explain to me how the C7 ACERT ECM works, how it electronically govenor works, how the ECM uses the inputs from the engine sensors to select the FRC and torque maps, pictures will help me alot. How the derating of the engine happens. I want to know everything I can, please help. I have some understanding of the HEUI system components and the IAPCV feedback loop.
Model: Coal Loader
Engine: C7 ACERT Ser.No;: JTF07189
Hi. Thanks for using JA! I will try and help you out.The ECM contains millions of fuel delivery and control maps for every possible operating condition. No matter what pressure or temperature is happening, the ECM has a map that tells the max amount of fuel that can be delivered to the injectors. Actually, the ECM is the body and there is a brain inside that is called the Personality Module. The Module is what has all the control maps inside. To delivery more fuel to the injectors, the ECM simply holds the pulse of AC current longer to the injectors. For example, when the coolant temp is OK, the intake air temp is Ok, the ECM looks at the boost pressure of the engine. Each increase in boost pressure will increase the amount of fuel that can be delivered to the engine. As far as derating, the ECM constantly looks at oil pressure, coolant temp, Intake air temp, and heui pressure. If the oil pressure gets to low, coolant temp to high, injection pressure to low or high, or the intake temp get to high, the ECM will cut back on the fuel that is delivered in order to keep the engine from damaging itself. I hope this info was helpful. Please let me know if you need more help or have more questions.
Thank you for the feedback. Ok, so as to my understanding. Correct me if I am wrong. The atmospheric sensor value gets measured and send to the ECM together with the boost pressure value measured. How does this value effect the fuel ratio control and torque maps? If I was going to use a block diagram to explain it to somoene. Help me with this if you like. So we will have (blocks), FRC maps, Torque Maps, Derates, Electronic Governor, Engine Speed/Timing Signal, Fuel Injection Control, Shutdown Inputs, Timing Control, Engine Control Logic, Temperature and Pressure (excluding the Boost and Atmospheric) sensor inputs, Boost and Atmospheric pressure sensors, IAPCV output and Injector outputs. How would I link the relationship to all these blocks and the information sharing that happens between these compponents? Please be paitient I am a little slow but retention is good.
Yes that is correct. The sensors send signals back to the ECM and the ECM follows the maps inside the ECM and determines the fuel delivery to the Injectors.
The higher the attitude, the less fuel the ECM will deliver to the injectors.
The higher the boost pressure, the more fuel the ECM will deliver to the injectors.
The higher the RPM's, the higher the Actuation Pressure.
Thanks for the feedback. I am going to take this information that you provide and chew on it, do some research. I would appreciate it if you could recommend reading resources available.
You are very welcome. I can't think of any resourses right off hand that will explain this. I will look and see if I can come up with some information.
23 Years Caterpillar Engine experience.