Chip Tuning, Remapping, ECU: Glossary to Your Car Computer

Know About Chip Tuning, Remapping, ECU

Looking to modify the computers in your car to get more power or efficiency? A quick Google search can be incredibly confusing. If you’re having trouble telling the different ECUs apart or comparing chip tuning vs. remapping, this quick guide can help you understand what they are.

Chip Tuning:

Early engine computers were first introduced in the 1980s and changed the way that engines were tuned up. Suddenly tune-ups were no longer about adjusting parts like a carburetor. In order to change key engine parameters, the chip had to be physically removed and replaced with a new chip. This was the original chip tuning, where the tune-up involved switching out the chip.

This term gets a little murky as technology evolved. The introduction of diagnostic ports meant chips didn’t have to be removed to be changed. The diagnostic ports allowed direct software access, so the chips could be reprogrammed without being removed. Today, chip tuning can refer to either replacing the chip completely or reprogramming the chip. But technically, it’s when the chip is removed and replaced with a customized chip.

Engine Remapping:

Remapping happens when the software in the chip is changed without changing the chip itself. The existing engine map is coded into the software of the engine’s computer. This software is then overwritten with a new engine map, or remapped.

If this sounds like modern chip tuning, that’s because many people will call it chip tuning, but technically it’s not chip tuning. A good way to remember the difference is that chip tuning involves changing the chip, while remapping involves changing the software.

Electronic Control Unit:

These are the actual computers in your car, also known simply as ECUs. The name refers to the entire unit itself, which consists of a computer board inside a casing with ports to connect it to the car. There are a wide variety of different ECUs scattered around your car, controlling things like your in-dash system, power steering, anti-lock brakes, engine, and more. Any time anything electronic is run, there’s an ECU behind it.

ECU or ECM:

Here’s yet another common place for confusion. The Electronic Control Unit that controls how the engine works is know as either the Engine Control Module (ECM) or the Engine Control Unit (ECU). This is the specific computer unit that controls engine settings like the timing, fuel injectors, etc.

Powertrain Control Module:

Just to make things even more interesting, there are also Powertrain Control Modules, or PCMs. These control both the engine and the transmission settings, and are more common in cars from the 1990s to early 2000s. Modern cars, however, have a separate ECU/ECM just for the engine controls.

Performance Chip:

These are the aftermarket chips designed to replace the manufacturer’s chips or software. There are a couple different types. Control modules are permanently installed between the sensors and the ECU, while power programmers are temporarily used to change settings through a diagnostic port. Both of these are widely available options, but don’t offer the customization of a professional chip tuning or remapping.

Chip Tuning vs. Performance Tuning

Chip Tuning vs. Performance Tuning

When it comes to getting more out of your engine, two of your big options are chip tuning and performance tuning. These are both types of engine tuning, each with their own benefits, and their own costs.

Chip Tuning

Originally, chip tuning meant that the chips in the ECU (Engine Control Unit) were removed and replaced with chips that had different software. The introduction of diagnostic ports to car computer systems opened the door for engine remapping, or rewriting the software without having to replace the chip. When a lot of people refer to chip tuning today, they actually mean remapping.

On the low end, you can simply buy a chip module that plugs into the diagnostic port to change the programming. This can have unpredictable results, since the module isn’t specifically made for your car and driving conditions. For the best results, chip tuning should be done by a professional. After installing a high quality chip, they’ll often put your car on a rolling road. They’ll run a series of diagnostic tests using precise machinery while the car’s running, then adjust the software accordingly.

Performance Tuning

While chip tuning deals exclusively with the software, performance tuning mostly concentrates on the physical parts of the engine. The vast majority of these hardware modifications or improvements concentrate on the powertrain, such as the cylinders, exhaust, transmission, and more. Performance tuning is almost always focused on getting more power out of the engine.

Performance tuning can be done by car owners in their garages, but they really have to know what they’re doing. Actions like boring out the pistons, installing a custom exhaust system and changing the compression chamber size are very complicated procedures that have to be done to very narrow margins. Owners will often find that they get the best results when they have the performance tuning done by a professional shop.

Combine the Tunings

If you really want to get the most performance possible out of your car’s engine, then you’ll probably want to combine both performance tuning and chip tuning. Performance tuning will allow you to switch out parts and tweak engine parameters to get as much as possible out of the engine.

Once you’ve got all of the physical parts fine-tuned, chip tuning will allow you to make sure that the software is lined up to get you the best response possible out of your upgraded engine. In fact, many of the pro shops that can help with performance tuning can also help with any chip tuning or remapping that needs to be done.