A car is an engineering and technological marvel. Something that we rarely look at and go hmm … wonder how they got here from the wheel and logs of wood. I am not going to go into the history of how the car came into existence. For decades, it was up to the driver’s skills and intuition to survey the environment and make the necessary adjustments to the steering, brakes and throttle to maintain control and avoid accidents. But gradually, over the past several years and without most of us noticing, that control has been migrating from the driver to the driven. Cars of today rely more and more on computers, compared to the cars of the past. Technology is getting more advanced and the automobile industry has always been trying to use that to their advantage.
More and more functions that used to be operated manually are now done electronically. The engine and parts under the hood power the car, but it’s the microprocessors that tell it what to do. You would be surprised in exactly how many functions have something to do computers, I thought it might be a good idea to actually list out a few and see what is in store in the future as well. Here is a list of a few of those:
- ECU- controls engine functions : The ECU is a pre-programmed, triple microprocessor digital computer. It regulates ignition timing, air-fuel ratio, emission control devices, charging system, certain transmission features, speed control, air conditioning compressor clutch engagement and idle speed. The ECU can adapt its programming to meet changing operating conditions.
- Airbag Module : The microprocessor in the Airbag Control Module contains the supplemental restraint system logic circuits and controls all of the supplemental restraint system components. Though the first cars with airbags debuted in the early ’70s; Chrysler is the first to make them standard in cars, in 1988. It protects you in a rollover, and cushions your knee.
- Body Controller : The BCM utilizes integrated circuitry and information carried on the Programmable Communications Interface (PCI) data bus network along with many hard wired inputs to monitor many sensor and switch inputs throughout the vehicle. The BCM supports many body electrical features such as Interior Lighting, Exterior Lighting, Intermittent Wipers, Remote Radio, Accessory Delay, and Heated Seats.
- Driver’s Door Module : The Door Modules control various electronic features such as power door locks, power windows, power mirrors, courtesy lighting, and the lift gate lock motor.
- Cruise Control Module– Regulates speed while in cruise control wherein the driver can select a certain speed and the car will maintain it.
- Climate Control Module– Monitors interior temperature and controls the heating and cooling systems
- Sunroof Module : Controls operation of the sunroof Open, Close and Vent Functions.
- Transmission Controller : The Transmission Control Module controls all electronic operations of the transmission. The TCM receives information regarding vehicle operation from both direct and indirect inputs, and selects the operational mode of the transmission. Based on the information received from these various inputs, the TCM determines the appropriate shift schedule and shift points, depending on the present operating conditions and driver demand. This is possible through the control of various direct and indirect outputs.
- ABS Module : controls anti-lock brakes and may handle the traction-control and stability-control systems. Also controls Electronic Brake Distribution (EBD), an electronically controlled proportioning valve.
- Power Distribution Box Module- controls relays in the power distribution box
- Instrument Panel : The Mechanical Instrument Cluster (MIC) provides gauge and indicator control. The MIC utilizes the PCI Bus to obtain most, but not all, of the information needed to control the gauges and indicators. Additionally they may also include Compass, temperature, trip computer, information center (EVIC).
- Rain Sense Module : The microprocessor-based Rain Sensor Module senses moisture in the wipe pattern on the outside of the windshield glass and sends wipe commands to the Body Control Module (BCM). Four InfraRed (IR) diodes within the RSM generate IR light beams that are aimed by four of the convex optical lenses near the base of the module through the windshield glass. Four additional convex optical lenses near the top of the RSM are focused on the IR light beams on the outside of the windshield glass and allow the two photocells within the module to sense changes in the intensity of these IR light beams. When sufficient moisture accumulates within the wipe pattern of the windshield glass, the RSM detects a change in the monitored IR light beam intensity.
- Sentry Key Immobilizer : The Sentry Key Immobilizer Module contains a Radio Frequency (RF) transceiver and a microprocessor. The SKIM transmits RF signals to, and receives RF signals from the Sentry Key transponder through a tuned antenna ring integral to the SKIM housing. When the ignition switch is turned to the On position, the SKIM transmits an RF signal to the transponder in the ignition key. The SKIM then waits for an RF signal response from the transponder. If the response received identifies the key as valid, the SKIM sends a valid key message to the PCM over the PCI data bus. If the response received identifies the key as invalid, or if no response is received from the key transponder, the SKIM sends an invalid key message to the PCM. The PCM will enable or disable engine operation based upon the status of the SKIM messages.
The processor that’s the most important is the ECU and it stands for the engine control unit. It controls the engine functions like the spark timing and obtaining the correct fuel and air mixture to intake into the engine block. It can also manage the emissions and the fuel economy of the car, it does so by creating the perfect ratio of fuel/air mixture. The ECU has a 32-bit, 40MHz processor, which is a lot less than a computer, but then again the car doesn’t need all that. Cars today may have as many as 50 microprocessors, many of which make them easier to service. Every engine, every vehicle and every computer system is different — but all the sensors, all the output devices, must be in perfect “sync” for cars, minivans, trucks and SUVs to run efficiently. You can check out a pretty good list of the sensors here.
When automobiles were first invented, none of these microprocessors were necessary and were also non-existent. So why such the increase in microprocessors to cars? Should it not make them more complicated? These extensive numbers of computers in cars actually simplify many of the tasks to create a vehicle. First off, there are new laws and standards that cars must meet. Engine controls must meet emission laws and fuel economy standards; meaning something must control the amount of pollution leaving the exhaust and the car must get a reasonable mile to the gallon. Computers also help give advanced diagnostics and help mechanics quickly discover a problem. They also simplify the manufacture and design of cars, as well as simplify the wiring. Microprocessors are also proving to help with safety, convenience, and comfort features.
Another great advantage to computers in cars is multiplexing. This is a method that simplifies the wiring, preventing wires from getting out of control. Each module is controlling a small aspect of the car, and these modules are attached to the communications bus which can carry it wherever it needs to go. For example, when you hit the window button in your car the driver’s door module sends that information to the bus, which gives it to the body controller which opens activates the windows motor. This is much more efficient then running wires from every switch and sensor to the part it controls. The Volvo S80 is a great example of the new technologies of multiplexing. Microprocessors are also to thank for saving lives; they control important safety features that have proved to save lives throughout the years. They control the anti-lock brakes system (ABS), the airbags, and more recently the traction-control and stability-control systems. Each one of these new features requires another module which contains many microprocessors. The Volvo SCC previews some of the future safety features that we may see more of. This vehicle is capable of adjusting the seat, steering wheel, floor, pedals, and the center console by scanning sensors in the position of the driver’s eyes to adjust the most comfortable position for the driver. It also has adaptive headlights which adjust the lighting according to the speed and steering of the car. The rearview mirrors and rear bumper are active and alert when approaching traffic is entering the drivers blind spot. It even has a remain-in-lane advancement which monitors the cars position in relation to the centerline and side-marker lines for 20 meters ahead of the car. When the car starts to swerve out of its lane, then it alerts the driver.
Wow, so if they can do that much with microprocessors, I am definitely going to keep an eye out for these enhancements for further updates. All I can say for the time being is Watch this space. I am sure we are reaching closer to the KITT car of the very famous Knight Rider Series.