Posted in: ECU

5 Signs Your Engine Control Unit is Failing

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Today’s automobiles are more advanced than ever before, thanks in large part to the advent of onboard computer systems. Sophisticated electronics are responsible for a multitude of different functions these days, providing detailed adjustment of the smallest parts and full control of many of the largest. One of the most crucial systems is known as the engine control unit—in essence, a computer that lives under your car or truck’s hood and helps ensure peak performance from your motor at every turn. As the ECU stands as one of any vehicle’s cornerstone components, being able to swiftly identify problems is a must for any driver. Learn more about this essential electrical system today and find out how to protect your ride from falling victim to major repair needs.


What an ECU Does For You


It can be easy to take any of a car’s innerworkings for granted—out of sight, out of mind, so goes the saying. An engine control unit is one component that can definitely fall under this category. The average ECU is roughly the same size as your typical tablet, and it looks far from just about any of the rugged mechanical components that it helps to drive. It is essentially a modestly sized circuit board that is housed in some manner of protective casing, but it takes on a very big role in keeping your modern motor vehicle performing at its best.


This unit depends on a collection of sensors in order to analyze a wide range of variables, and recalibrates your engine’s performance accordingly. Each sensor serves one specific purpose, measuring values such as air-fuel ratio (ensuring that your engine is not running too lean or too rich), mass air flow (the amount of air entering into the engine) and manifold absolute pressure (a value necessary in metering fuel quantity). By making detailed adjustments based on these various data points, an engine control unit is able to calibrate actuators to maintain greater efficiency, a notable benefit to car, driver and environment alike.


Some of the other major elements that your automobile’s ECU regulates are likely to include:


  • Engine revolutions per minute
  • Idle speed control
  • Variable valve timing


Just as with any component, these capable control units are built to last for the long haul. However, that doesn’t necessarily mean that problems can’t or won’t still occur. Even the most reliable ECUs can experience failures as result of exposure to any number of mechanical or environmental hazards, and knowing the signs of trouble is key to limiting potential damage.


Identifying Engine Control Unit Failure


More often than not, a problematic unit is going to provide at least one commonly observable red flag. Some of these indicators are performance-oriented, although some are built right into your car or truck for purposes of early warning and troubleshooting convenience. Should you encounter any of the following conditions, take the time to get an accurate diagnosis so you can root out the trouble and remain on the road confidently.


  1. Inability to Start Your Vehicle


Few situations are more dreadful than sitting down in the driver’s seat, turning your ignition switch and being met with a sputtering non-start. Unfortunately, ECU failure is one potential cause of a dead car or truck, even if the engine itself is still capable of cranking over. As with many major automotive issues, failed starts can potentially be caused by many different factors, so be sure that you are confident in the diagnosis before beginning any work.


  1. Reduced Engine Power


Whether you depend on a trusty commuter car or you drive a tricked-out performance machine, you know what your vehicle feels like when it’s running right. The failure of an engine control unit can quickly throw a wrench into the operation, resulting in unwanted changes to fuel and/or timing settings. These kinds of variances are known to result in noticeable losses in engine power and acceleration, in addition to one more of drivers’ most dreaded conditions …


  1. Diminished Fuel Economy


For many motorists, one of the primary benefits offered by modern electronic control systems is the improvement in fuel efficiency. Your engine’s sensors measure air and fuel amounts in great detail to ensure the ideal mix, and when a control unit is incapable of making that distinction, expect to notice the impact next time you’re at the gas pump.


  1. Dashboard Warning Signs


When the indicator on your dashboard advises you to check on your engine, you should definitely take heed. This warning light brightens up to inform you that a problem has been identified by your onboard diagnostic system, based on information provided by a circuit or sensor somewhere within your car or truck. At times, this light activates only temporarily, and may even reset itself the next time you fire up your ride.


It’s always smart to avoid driving any more than you absolutely must if this indicator is illuminated, whether it occurs as you start your automobile or while you’re already on the road. Getting an accurate reading of the diagnostic trouble code and making sure you know what type of fix is necessary is the advisable course of action.


  1. Misfiring or Stalling


Among the more frustrating signs of a failing engine control unit are stalls and misfires from your engine. While these kinds of occurrences are always stressful, they may also be tough to figure out, as this is one symptom that can strike with inconsistency. Your engine may operate as expected for days or weeks at a stretch, then stall out on the road with little or no advance warning. Make it a priority to investigate any such motor issues early on so you can identify whether it’s a bad ECU or another culprit causing your problem.


Common Causes of Failure


Sometimes just as important as the “what” is the “why”—in this case, why would an ECU fail? There are plenty of potential reasons, some more common than others. A few of the most frequent to look out for:


  • Voltage issues: Some starters are equipped with override sensors that regulate voltage; should one of these parts fail, it may leave your ECU vulnerable. By contrast, insufficient voltage is also a frequent culprit in engine control issues. Anything less than nine steady volts may prove to be insufficient power for your vehicle’s unit.
  • Battery woes: It goes without saying that an entirely dead battery is going to put a halt to your travels. It’s also worth mentioning that an engine control unit can fail as result of fading power cells, or even as result of an improper attempt to jump a weak battery. Always be confident in all your connections before jumping a vehicle, or you may end up a bigger headache than you started with.
  • Corrosion problems: While any good ECU is well sealed against environmental intrusion, any component can eventually break down. Should a casing become compromised, as through hard, repetitive vibrations and jostling over time, moisture could make its way inside. Even the smallest amounts of water can lead to damaging corrosion, one of the greatest threats to any electrical system or component.


Other Reasons to Replace


Not every situation that calls for a new engine control unit is necessarily a negative one. Many drivers make the move to an upgraded ECU in order to accommodate improvements to an engine itself, if not another of a vehicle’s primary components. It may be necessary to install what is known as a programmable control unit to meet the needs presented by any of these auto modifications:


  • Changes to an exhaust system or transmission
  • Supercharging or turbocharging an engine
  • Upgrading spark plugs and/or fuel injection components


ECUs receive and transmit so much detailed information that specified programming becomes necessary when new or upgraded systems come into play. Just consider how many individual parameters are often dictated by an engine control unit:


  • Launch control
  • Fuel injection volume
  • Ignition timing
  • Gear shift mapping
  • Throttle/fuel volume mapping
  • Variable cam timing
  • Fuel pressure regulation
  • Staged fuel injection


Bear in mind that not all ECUs are made the same. The system that is initially installed in your car or truck when it ships from the factory may be adequate for day-to-day driving in town and on the freeway, but won’t necessarily be right for higher-performance machines. Competitive racers can even find engine control units specifically designed to suit the needs of their vehicles, complete with data logging features that preserve useful information to identify faults or misfires.


Service and Selection


A good engine control unit helps to ensure you get the most out of every mile in your automobile, so make the smart call when you know a replacement is in order. If you have observed any indications of problems in your system, or if you’re considering an upgrade to any dependent components, then a new ECU is right for you. Trust Importapart for the top-quality parts and accessories you need to maximize your vehicle’s performance every time. Our customers are our top priority, so shop today and find out what great service is all about.