Going back: The CHECK ENGINE LIGHT

Scenario: You have recently had your vehicle repaired because of the CHECK ENGINE LIGHT. The repair was costly, and a couple of days later, the light is on again! You have to take the vehicle back to the shop! What’s up with that?
First, let me explain what a CHECK ENGINE LIGHT is. Vehicles have an engine computer and several sensors that monitor and control many different functions on the engine. When the computer does not receive the correct data, or has a problem controlling something, it will store a default code and turn on the CHECK ENGINE LIGHT. This code aids the technician with the diagnosis of a particular system.
Always make sure that this default code and the actual repair performed is documented on the repair order. The reason for this documentation is that there are several faults that will turn on a CHECK ENGINE LIGHT. The light coming back on may be due to something entirely different and is not related at all to the last repair.
Upon returning to the shop, the fault code should be checked by the service writer or manager before the vehicle is taken back to the technician. This is a simple procedure that should be done at no charge. If it is the same fault code, the manager needs to be notified in order for follow up on the previous repair and get the vehicle properly fixed. A good repair shop will do this to the customer’s satisfaction.
Note: If the fault code is different and it is a new problem with the vehicle, the shop is not responsible for the cost of the diagnostics and repair.