Car DIY repair tips: How to install and replace the car ECU

Can an ECU be replaced via Do-It-Yourself (DIY) or should it be done by a skilled technician? Most up to date current model are all equipped with an ECU or ECM that controls car features.

1. What about cars and ECUs?

For most car owners who are not so familiar with cars now; they’re in luck because cars have become more efficient machines! It can do so many things that cars wouldn’t do before; it can park by itself and do other tricks too.

Compare this to older and fewer premium cars, offer more features that are either essential or sheer extravagances.

These features are controlled and regulated by the car ECU; that creates all the magic of modern automotive technology!

Installing and replacing the car ECU by yourself is not that easy

But, all this technology will come at a price; and it won’t come easy as straight out DIY repair too. One of the things to do is install and replace the car ECU. Many will be scratching their heads because; it may be the first time they have come across it as well.

It’s another of car maintenance that may or may be opted out of, just because it’s very delicate to even consider it.

Consider all the options before even attempting to replace the ECU, but most would hire technicians to do it though. But, some advanced gearheads may want a shot at it to save expenses or just try it out.

Better think about it; before attempting to install and replace the car ECU, which is all good in theory but the practice is not as easy as it seems.

Consider all the options before even attempting to replace the ECU

>>> Read more: Real car deal: 7 Pros & Cons of car Engine control unit (ECU).

2. Steps to replacing the car ECU

Keep in mind that DIY has limitations; and when any problem is encountered, it’s better to stop and get a qualified tech to pick up where you left off! Another thing about car ECUs is that it is expensive to replace, reprogram, and will need the exact ECU not be interchangeable with other cars. Think about it and go through all options.

What are the symptoms of a faulty ECU that may need replacement?

Off the bat, there are signs that any faulty ECU may manifest, but some of these problems can be fixed with remapping or reprogramming. Better to get it scanned or checked by a car tech or if a scanner module can be acquired.

If the Scanner module can be acquired, then get it because it costs just to have an ECU scanned. Also, ECU services are expensive; but soft ECU skills may save some costs, without spending more.

Better to get it scanned or checked by a car tech or if a scanner module can be acquired

Symptom #1. Bad Engine

The engine performs with less power, and there is noticed lag in everything too. Another big headache is bad combustion which is a big problem, that should be checked asap.

If the engine icons go red and never stops; then the ECU should be checked. An ECU without any problem should not light up the dash icon unless it is worse than it seems.

Symptom #2. Engine Stalled

When running an engine should fire the air and fuel mixture inside the manifold regularly. When the engine seems to cough up and clear unpredictably and has times that firing inside the manifold is inconsistent.

Stalling will lessen performance and can affect other systems. Problems with the ECU should be verified before even considering its replacement.

Stalling will lessen performance and can affect other systems

>>> Also check: Most common car ECU problems & How to fix them.

Symptom #3. Horrible fuel economy

When it comes to combusting fuel and air, the ECU controls the amount and the timing very precisely! If there is a glitch or any problem with ECU; it means that firing and burning are inefficient that could mean problems with the sensors or with the ECU itself too.

When extreme heat caused by wrong programming can make it worse, and further worsen the ECU problem by adding more unwanted ones accidentally!

Symptom #4. Engine warning light and other indicators

On the dash; there are many lights and indicators that shouldn’t light up, under any circumstance! Never touch or replace an ECU; unless the scanner module reads error all over.

On the dash; there are many lights and indicators that shouldn’t light up in any cases

Symptom #5. Car won’t start

If the battery is okay and the alternator checks out fine, then the immobilizer has been tripped. Another problem is the RFID chip may have been lost, because the key fob opened.

>>> Relevant article: 10 common reasons why your car won't start & How to troubleshoot them.

Steps to replace ECM

If the signs indicate that the ECU is at fault, here are the steps to have it removed and replaced. The exact CPU should be used for the right car model so there wouldn’t be a need to reprogram it. Do this to install and replace the car ECU, the right way!

How to replace car computer - video instruction

Step #1. Find the ECU

Locate the ECU in the car, check the owner’s manual to find out where it is.

Step #2. Shutting power supply to ECU 

Disconnect the battery from the connectors, and consult further about extra steps if needed!

Step #3. Cutting power to ECU

Make sure to correctly disconnect the ECU computer from the power supply. Read more and consult manual about it.

Make sure to correctly disconnect the ECU computer from the power supply

>>> Worth your attention: 7 must-know tips to extend ECU-based cars' life expectancy.

Step #4. ECU removal

The ECU is removed by unscrewing and holding it in place; with a socket wrench. With this done; take out faulty ECU and put in the new one.

Step #5. Replacing ECU

Do the reverse of ECU removal and re-secure the ECU in place. Make sure everything is connected and tighten well!

Step #6. Reconnecting the power supply

With the ECU securely in place, have all power connectors fastened to the ECU tight? Lock everything in and keep it tight.

Step #7. Re-engage the car battery

Mount all battery cables securely and tight, with collars tightened well.

Take note with all the indication; whether it should be done DIY though but it’s always an open option

Step #8. Rebooting the ECU

Re-start engine and let it run and idle for five minutes or so. If there is a problem with ECU codes, the red check engine will light up!

Overall; this is how to install and replace the car ECU properly which is better done by pros, but DIY is an option as well to consider. Take note with all the indication; whether it should be done DIY though but it’s always an open option. Think about it before anything else!

Looking for additional information about car features and other car concerns? Philkotse.com is right here for you!