As an auto repair expert at vcdstool.com, I often encounter questions about using scan tools for diagnosing alternator issues. While scan tools offer valuable insights, it’s crucial to understand their limitations and when traditional diagnostic methods are still necessary. Many technicians, both seasoned and new, wonder about the extent to which scan tools can pinpoint charging system problems, especially when considering different scan tool brands available on the market, even pondering “Who Makes The Icon Scan Tool” as they try to navigate the diagnostic process. Let’s break down what you can realistically learn from a scan tool when troubleshooting your car’s charging system.
What can a scan tool actually tell you about your alternator? Firstly, it might indicate if a charging fault code is present, although, surprisingly, not all vehicles will even register a code for charging system malfunctions. Secondly, you can usually see the current system voltage. Thirdly, the scan tool often displays the commanded or target voltage – the voltage the car’s computer (PCM) is aiming for. For example, a Kia might be designed to charge at around 12.3 volts at idle, and the scan tool will confirm if it’s meeting this target. Fourthly, and very importantly, you can observe the commanded duty cycle or output to the alternator. This tells you how hard the PCM is trying to make the alternator work. Is it maxing out its command (say, 100% duty cycle) and still not achieving proper charging? Does the PCM even recognize a problem? And crucially, is the PCM even the module controlling the alternator in your specific vehicle?
