Powertrain control modules or PCM are often regarded as the foundation of an engine control system. The module is among many ECUs that are used in vehicles. Some modern cars consist of numerous electronic control units inside them. These types of cars are not only visually appealing but intelligent as well. Beneath their classy exterior curves and elegant contours, they contain powerful microcontrollers that give the type of processing power that makes desktop computers look like toys.
Controlling Engine Functions
PCMs serve as the brains of modern vehicles and take charge of regulating multiple important functions inside the engine of a car. Proper PCM functions have a direct impact on the vehicle’s performance and it is essential to be aware of how the system works. This embedded system is designed to control the functions of a car’s engine.
The PCM is basically a small computer that takes care of the optimal operations of the engine. There are various factors that differentiate a car’s computer from the desktop or laptop that you use at home or work.
Unlike a personal computer, the whole computing system of the PCM, including supporting peripherals, memory and processor, have all been made as small as possible to facilitate mounting them on one tiny chip or circuit board.
If the system of a general purpose computer fails, major issues are rare. However, the PCM is expected to perform in real-time and should ideally be resistant to failure. It has the responsibility of managing multiple vital processes inside the engine of a car and failure can lead to dire consequences.
How PCM Works
The functionality of the PCM in a car engine relies on an intricate connection and sensitivity to any disturbance within this connection.
The PCM is located at the central point of a vehicle’s electronic web. Every part of this system is connected to one of the several sensors that provide it with feedback constantly. This feedback is sued to accurately measure multiple different parameters that related to the engine and suitable adjustments are made to control them.
Modern vehicle PCMs usually have the ability to take care of several different parameters at the same time.
Some of the many essential processes that a PCM looks after include the following.
Adjusting the crucial air to gas ratio that is pumped into the car’s cylinders. This saves fuel while increasing the efficiency of the vehicle. For instance, when the engine is cold, this is sensed by the PCM and the ratio of gas is adjusted in order for it to be more than air. This facilitates higher combustion and results in the car warming up faster.
After the engine is warmed up, this is sensed by the PCM again and the ration is adjusted to reduce the fuel that is being pumped in.
It takes care of the spark plugs ignition timing within the cylinders of the car. It can make spark plugs fire in slower or faster sequences according to different conditions.
The PCM takes care of the vehicle’s idling speed. The engine is required to sun smoothly at idle speed. The PCM lowers or raises the idling speed and keeps the engine running smoothly.