I have a 2004 Hyundai Accent I just bought and the malfunction indicator light came on and stayed on while driving. I'm hoping it's just the gas cap, which I will tighten, otherwise, it's still under the NY state lemon law

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My name is Ben and I'm your guru, i.e., mentor, an influential teacher or popular expert: a management guru. - origin from Sanskrit, 'weighty, grave'.for today.


Subject: Engine warning lighr comes on

Customer's exact description: I have a 2004 Hyundai Accent I just bought and the malfunction indicator light came on and stayed on while driving. I'm hoping it's just the gas cap, which I will tighten, otherwise, it's still under the NY state lemon law

Discussion: The customer needs to use a code scanner to solve the problem

Your local dealer is going to charge you at least $100 to perform a diagnostic scan. However, AutoZone will do the same job at no cost. There is no other way to efficiently diagnose the problem. Anyone who tells you differently is guessing.
You car has a computer and memory and probably knows exactly what the problem is. That on-board computer is just waiting for you to ask, "What's wrong".

First a little background for your edification. You may be aware of all this but we've never done business before and all assumptions are off the table.

For an engine - make that any engine and irrespective of manufacturer - to run, you need three things to happen inside the engine, compression, fuel and ignition, without any one of these components the engine will not run.

Compression - Engine compression caused by crankshaft rotation and pistons moving up and down inside the engine block. If the timing belt or timing chain fails it will cause the camshaft to become out of correlation with the crankshaft or allow the camshaft to stop rotating. Either of these conditions will cause the engine to lose compression and sometimes cause internal engine damage.
Fuel Delivery System - The fuel system includes: fuel pump, fuel injectors, pressure regulator, fuel filter and pressure lines. This system is used to supply fuel under pressure to the fuel injection system, the lack of fuel pressure or volume will cause the fuel delivery system to fail and the engine to stall or not start.
Ignition Spark Delivery System - The ignition system components include: spark plugs, spark plug wires, distributor (if applicable), crankshaft angle sensor, camshaft angle sensor, ignition coil, ignition module, knock sensor and PCM (powertrain control module). The engine relies on the ignition spark to be delivered to the combustion camber at the correct time. If the ignition spark stops or is delivered at the wrong time the engine will not run or run poorly.

Whenever your engine cranks but does not start, runs rough, staggers, sags or cuts off, follow this Troubleshooting Guide. Some of these steps require a code scanner. They are costly but remember that AutoZone will loan you one for FREE.

Most vehicles operate by the same principle; basic troubleshooting procedures therefore apply to most cars.

Step 1: Remember that anytime you have a problem with electronically controlled components such as an engine, transmission, ABS brake, or SRS (supplemental restraint system, Air Bag) inspect all fuses using a test light and check the under hood power distribution center and under dash fuse panels. If all fuses test okay continue to the next step.
Step 2: To check for problems with electronically controlled components such as an engine, transmission, ABS brake, or SRS (supplemental restraint system, Air Bag) and the fuses test okay a trouble code scan is needed to identify any system trouble. Use a simple scanner tool to retrieve trouble codes and see if they relate to the specific problem, like a crank angle sensor failure code. If the trouble code present does not pertain to the immediate problem like an EVAP code ignore it until a later time, after the car is running.

The reason we repair non-related codes after the engine is running is because sometime false codes can be triggered by the engine not running. Once the engine is running again the code present might cycle and turn itself off. You might say "if the engine doesn't run shouldn't it have a trouble code?" Sometimes conditions occur that will not be detected by the computer, example: if the fuel pump fails the computer cannot detect the failure, so the engine doesn't start and the computer thinks everything is okay with no codes. If no trouble codes are present proceed to the next step.

If you have trouble using the code scanner or interpreting the codes click on the following link and use my access code (carrepair): Free Automotive Repair information for Users of a Code Scanner



Ben