In the slang of automobiles and the environment of beginner mechanics, one can often come across a strange question: where is the TV under the hood? Of course, we are not talking about a full-fledged device for viewing gears installed next to the engine. By this term, drivers usually mean electronic control unit (ECU) or a complex multimedia system, the components of which can be carried into the underhood space. Confusion arises due to the visual similarity of some sealed blocks with household appliances or due to specific interference on the screen of the standard tape recorder.
In fact, installing a full screen in the engine compartment is technically meaningless, since there is nothing worth watching except the engine. However, electrical problems, which users figuratively call a “television”, can cause serious trouble. Display glitchesSound distortion or complete failure of a multimedia system is often associated with problems of wiring, leaving the hood space to various sensors and controllers.
In this article, we will discuss in detail what lies behind this term, why electronics suffer from moisture and how to correctly diagnose malfunctions. Understanding architecture The electric grid of a modern car will help you avoid costly repairs and false conclusions when looking for faults.
What is the term “television” in the engine compartment?
When experienced craftsmen use the word “television” in the context of the under-hood space, they most often mean motor-control Or an ABS unit, which is visually an aluminum box with many wires. In some models, such as older versions of Ford or Volkswagen, the unit can be located in places where water can potentially flow, creating the illusion of a “drowned TV”.
Another interpretation is related to antenna-amplifiers and signal reception units, which are sometimes placed in the front of the car for better reception. If this unit fails or gets interference from the generator, distortions appear on the screen of the regular head unit (which is a real “television” in the cabin). The driver sees the ripples and says "the TV is glitching," although the problem lies under the hood.
It is important to understand that modern automotive electronics are a complex computer, not an analog device. Any interference with his work requires qualifications. Short circuit. In the power chain of such a unit can lead to burnout of the entire onboard network, so the diagnosis should be carried out carefully.
⚠️ Attention: Never attempt to open the aluminum housings of the control units under the hood. Inside is a vacuum filler or specific protection, the violation of which will lead to instant failure of the device due to the oxidation of contacts.
Why do the control units make them sealed?
Aluminum control unit housings (ECUs) are not only used for mechanical protection, but also work as cooling radiators. Inside, a thermal interface is often used to remove heat from the chips. Violation of tightness leads to condensation and rapid corrosion destruction of the tracks, which makes the block non-repairable.
Effects of Moisture and Condensate on Automotive Electronics
The under-hood space is an aggressive environment. Temperature changes, oil, gasoline and, of course, moisture create ideal conditions for corrosion. If you get water in your car, you will be the first to suffer. contact groups and connectors. Water containing salts and minerals becomes an excellent conductor, causing chaotic circuits that drivers mistaken for breaking the “TV” or screen.
Especially dangerous is condensate, formed during a sharp cooling of the hot engine. Moisture droplets settle on the cold metal parts of the control and drainage units deep into the connectors. Oxidation of contacts The process is slow but true. First, there are short-term failures in the operation of devices, then the system begins to issue errors that are difficult to diagnose.
To protect electronics manufacturers use special lubricants and sealants. However, over time, especially on cars with a run of more than 10 years, rubber seals dry up. It is critical to prevent this, otherwise corrosion He'll get to the circuit boards.
- 💧 Water in candle wells can penetrate the body of the ignition coil, creating a powerful interference to the radio receiver.
- ⚡ The oxidized “mass” of the engine causes voltage surges that “kill” sensitive multimedia electronics.
- 🌡️ Overheating of the under-hood space with working air conditioning in traffic jam accelerates the aging of wire insulation.
Regular engine washing with a high pressure kerkerkerker is the main cause of water entering the connectors and subsequent problems with electronics. Wash the engine only with a brush and a weak pressure, previously closing the sensitive zone.
Diagnostics of interference and problems with multimedia
If by “TV” you mean problems with the image on the display associated with the hood components, then you need to start the diagnosis with a check of the generator. Faulty. diode bridge The generator passes alternating current into the onboard network, creating a characteristic background and ripples on the screen. This is a classic problem that is often confused with the breakdown of the head unit itself.
The second step is to check the shielding of the wires. High-voltage ignition system wires (if your model has them) or nozzle wires can create an electromagnetic field that is induced onto the system’s low-current audio-video cables. In modern cars with digitally CAN-bus such tips can lead to loss of data packets and system freezes.
For accurate diagnosis, an oscilloscope or a high-quality multimeter is necessary. A simple “titling” often doesn’t give the full picture, as interference can be impulsive. It is important to check the status of minus-plum and their connection to the body and the engine.
| Symptom | Probable cause under the hood | Method of elimination |
|:--- |:--- |:--- |
| Rifts on the screen when the engine is running | Diode failure of the generator | Replacement of the diode bridge or generator |
| Loss of sound when lighting | Weak contact "mass" | Clearing contacts, setting additional mass |
| Unintentional track switching | Interference from ignition coils | Wire shielding, IB wire check |
| Complete screen quenching at start | Battery and starter voltage drawdown | Battery and starter check |
Location of electronic units in modern cars
Engineering thinking does not stand still, and the location of control units is constantly changing. In old cars. EBOU They were often hidden in the most unexpected places: under the windshield, in the wings or even in the door panels. However, in modern cars, there is a tendency to concentrate electronics in the cabin or in protected areas under the hood.
For example, many BMW and Mercedes models have engine control units located on the right side of the engine compartment, often under plastic casings. In cars of the VAG group (Volkswagen, Audi) is often located in the battery area or under the sparser. Knowledge of exact location switch-block It is necessary for proper diagnosis.
It is worth noting that in hybrid and electric cars under the hood (or in the front) are high-voltage inverter blocks. They have impressive dimensions and liquid cooling systems. It is difficult to confuse them with something else, but they are strictly regulated due to high voltage.
Typical ECU search sequence:1. Open the hood and remove the decorative plastic engine casing.
2. Check the space near the right splasher (often there is an ECU).
3. Check the area next to the battery (fuse units and BCM).
4. Look under the cooling system nozzles (there are often hidden sensors).
⚠️ Attention: When searching for blocks under the hood, be extremely careful with hot items. Do not touch the exhaust manifold, catalyst and pipes immediately after the engine stops. The risk of getting a 2-3 degree burn is very high.
Protection of wiring and connectors from an aggressive environment
Self-protection of electronics is not so much the installation of additional screens, as competent maintenance of existing systems. First rule: plug-in. Special sprays-lubricants based on lithium or silicone displace moisture and create a protective film that prevents oxidation.
The second important aspect is the integrity of the insulation. Rodents, vibration and time do their job. Cracks in the insulation of high-voltage wires or nozzle harnesses lead to current leaks. For recovery, you can use thermal shrinkage, but it is better to use car-stuff High quality that does not melt in the heat.
It is also worth paying attention to the drainage holes in the niches of the underhood space. If they are clogged with foliage, water will stagnate around the blocks, increasing humidity. Regular cleaning of these areas is a simple but effective preventive measure.
☑️ Seasonal Electrical Checkup
Can I install the screen in the under-hood space?
Theoretically, install a protected screen under the hood is possible, but practical sense in this zero. Even specialized industrial monitors with a protection class IP67 or IP68 They will not last long in conditions of vibration and temperature changes of the engine compartment. The plastic of the body will quickly become brittle, and the matrix can leak or stratify.
The only reasonable use of screens under the hood is specialized diagnostic equipment for racing cars, which is fixed for a short time for tests. In civilian cars, all data visualization is displayed in the cabin on a standard display or projector. Trying to make a TV to watch videos under the hood is insane, and will only damage property.
If you need to output data from sensors installed in the engine compartment (for example, turbine temperature or oil pressure), use wired lines to the cabin. Modern. digital Allows data to be transmitted over a single wire, minimizing the risk of interference.
If you need to display an image from a camera installed under the hood (for example, to check the operation of mechanisms), use wireless Wi-Fi cameras for outdoor surveillance. They are cheaper and easier to install than wired systems with monitors.
Frequently Asked Questions (FAQ)
Is it true that there is a satellite TV unit under the hood?
In the factory configuration, no. Satellite TV antennas (if any) are usually located on the roof. However, enthusiasts can install a receiver in the cabin, and the antenna amplifier can be brought closer to the roof or to the top of the hood space, but this is rare.
Why does the engine screen go off after washing?
Most likely, the water got into the connectors or on the contacts of the control units. The water closed the chain and the protection went off or there was a short circuit. It is necessary to dry the engine compartment with compressed air and let the car stand with the hood open.
Can I replace the EBU myself if it burns out?
Physically, you can replace the box, but the new unit will require binding to the immobilizer and configuration for your car. Without specialized equipment and software, the machine will not start. It's a job for a profile service.
How to distinguish noise from generator from problems with the speaker?
Turn on the engine. If the nature of the noise or ripples changes with the engine speed (frequency increases), the source of interference is the generator or ignition system. If the sound is static, the problem is with the head unit or speakers.