An electronic control unit is a device that does simply that – control electronics in some fashion. It’s an electrical circuit board that switches power on and off, changes electrical flow direction, adjusts, pulses or regulates power distribution, or otherwise controls electrical power. It’s usually a circuit board with resistors and switches all soldered together in a pattern that takes a genius to decipher. It falls just short of magic.
Your vehicle uses multiple ECUs, all serving a different purpose. One controls your heating and air conditioning system while another controls your transmission’s operation. There’s a module for your ignition system and another that operates your vehicle’s body controls. Power sliding doors and liftgates each have their own ECU too.
ECU testing can be a challenge, even at the best of times. When a diagnostic tool is plugged into your car’s dataport, it relies on information transmitted from the modules. If the ECU isn’t working right, it could send incorrect or incomplete information, sending you on a rabbit trail down the wrong path.
Eventually, sometimes after several attempts, you’ll discover an ECU repair is necessary. There’s an issue with that: there aren’t many places that perform ECU repairs. If you’re lucky, you’ll find someone in a distant city that works on them, and you can FedEx your ECU to them. Now your car is out of commission until you get the part back and reinstalled, and hopefully everything is working again.
Another problem is ECU repair cost. Fixing your ECU could be several hundred dollars in the end, and you might’ve been able to replace it with a new one for the same price. There’s no way to know ahead of time.
Yes and no. ‘ECM’ stands for ‘engine control module’, meaning it’s a specific type of ECU. Like the transmission control module (TCM) and body control module (BCM) it serves a particular role in your vehicle’s operation.
The ECM incorporates your engine’s electrical functions. It controls your fuel supply and injection systems, your ignition control, your cooling system, and even your emissions controls. It’s a computer that optimizes your engine’s performance multiple times per second and performs self-tests to make sure everything is working as it should.
In relation to the ECM, car problems can many:
Your engine could run rough due to a misfire.
Your Check Engine light could be on for no apparent reason.
A diagnostic scanner may not be able to read your car’s codes.
Your car might stutter or stumble, stall, or otherwise not perform as you’d expect it to.
For most vehicles, you don’t get an ECM repair performed. It’s just not a viable solution because it’s expensive, there aren’t many people who work on them, and it might not fix your issue unless you can pinpoint the failure. Engine computer repair may not last, even if it’s attempted, and you’ll find yourself dealing with the same issues all over again.
Instead, ECM replacement is the route most often traveled. The ECM is replaced with a new unit, which must then be programmed to your vehicle. The module could be a couple hundred dollars if your vehicle is common and pretty basic, or it could be well over a thousand dollars if you drive a fancy or premium brand.
Your ECM repair cost could likely be more than you want to spend on your car. In addition to the replacement module cost, you should expect several hundred dollars in diagnosis, replacement, and programming. It’s not unreasonable to see ECM repairs in excess of $1,500 or $2,000.
If your ECM has called it quits, you have a way out. CarBrain can buy your car from you online in as-is condition, whether the ECM is burned out or not. All you have to do is request a guaranteed offer for your car based on its condition. Once you accept our offer, we’ll get your car picked up free of charge and put money in your hand. One call or click is all it takes.