You probably know that when the Check Engine Light (CEL) illuminates in your vehicle, you should bring the vehicle to the garage to see what is wrong. When you do this, the first thing your mechanic does is plug in a code scanner to “read the codes”. A code scanner interfaces with the vehicle’s Powertrain Control Module (PCM) where all engine error codes are stored. This allows the mechanic to professionally diagnose the issue and solve it. Since 1995, cars have been made with OBDII ports that allow scanning PCM modules.
How Code Scanners Work:
The ignition, fuel injection system and automatic transmission on modern-day cars and trucks are run by the PCM. This is a computer that collects operating data from the engine and other systems on the car and then sends commands to the ignition coils, fuel injectors and other units. They also store some of this operating data in memory so that mechanics may get insight into what has been going on when service is needed.
When the CEL light on your vehicle’s instrument panel goes on, it means that the PCM is getting data from a sensor that indicates something is not working correctly. The PCM translates that sensor problem into a diagnostic code so a technician can read it and know where to seek out the problem. Sometimes some interpretation is involved when reading error codes, however, professional mechanics know many of the tricks.
How to Use a Code Scan Tool:
To get started, plug your scan tool into the OBD II connector under the dash of your vehicle. (If you can’t find the connector, look in your owner’s manual. You might find a website or forum that can help you too.) After you have it connected, turn the vehicle’s key on then follow the scan tool’s onscreen instructions. You will eventually get an option to check for trouble codes and you’ll press a button to get them. If you see any, it’s a good idea to write them down!
For interpretation, the manual that came with the scan tool might help, or use the internet. If you go online, to Google or another search engine, type in the model of your vehicle and then the code number that the scan tool displayed. You’ll find dozens of websites that can help you diagnose what the problem is. Keep in mind that most of the responses you receive will be non-professionals talking about the error code but usually, the solution will be identified by the more knowledgeable amateur mechanics on-line. Your ultimate resource is to have your local dealer, such as this local Dodge dealer in Langhorne, PA, check out the issue!
Not long ago code scanners were pricey as they were really just for professional service technicians. Today, a code scanner may be priced as low as $30. The inexpensive ones lack the fancy features of the high-end ones but they are useful, nonetheless. If you like understanding what’s going on deep down in your vehicle, consider getting one. They are widely available at auto parts stores these days, and online at a multitude of websites.
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