Pros: This device is easy to use and can save you from unnecessary repairs.
Cons: Some error codes descriptions may not be found, Internet lookup required
If you are considering spending $50 or more on a device that will enable you to read the fault codes from your vehicle's on board computer, don't hesitate. It will pay for itself the first time you reset the computer and the error message doesn't reappear. It will allow you to feel confident that necessary repairs are performed correctly.
I ordered the Actron CP9550 from Amazon when the "Check Engine" light came on in my 2005 Silverado. I was 300 miles from home and had no idea what was wrong. The engine was running fine, but this warning had me worried. After a few stops and a few miles in between, the "Check Engine" light went out. Should I take the truck in for service? The dealership charges $99 to read the code. Some places do it for less, some advertise reading the code for free. What's the catch?
The day after returning home, the "Check Engine" light came on again, and fortunately the Actron CP9550 arrived in the mail. There were two error codes, both the same, indicating a problem with the fuel evaporation filter. I felt confident bringing the truck to the service station, knowing that they would fix only the filter, since I told them I knew what the error code meant.
That same day, the "Check Engine" light came on, and stayed on, in our 2002 Sienna Minivan. I read the code, and although the Actron CP9550 did not have the description for this particular code built in, a quick search on the computer showed it was one of the four air/fuel mixture sensors on the engine. However, in reading some of the articles regarding this error code, a mechanic mentioned that some times this is a false error, and that resetting the computer and waiting for the error code to reappear might be a prudent choice. I reset the code with the Actron CP9550, and the minivan has been driven over 100 miles without the error code showing up again. This procedure may save me the $200 or so that replacing that sensor costs.
The Actron CP9550 is easy to use. Turn the ignition to "ON" without starting the engine, plug the Actron CP9550 into the connector located under the steering column (exact position varies by make and model of vehicle), and the error codes will be read. Push the "READ" button to step through the error codes if more than one appear. To erase a specific code, hold the "ERASE" button for three seconds until the screen displays "are you sure" and hold the "ERASE" button another three seconds. Be sure to make a note of the error code, so that you will know it's the same code if it pops up again on your dashboard.
While there are many models of the Actron code reader, some well below $50 and others approaching $200, the CP9550 was the least expensive model that had a second line on the display with a brief description of what the error code meant. While it is possible to just get the code and look it up on the Internet, I felt that the convenience of built in code descriptions was worth the cost, especially in the case of multiple error codes. The Actron CP9550 was $65 through Amazon, but I had put it in my Wish List for a while, and when I went back to order it, there was a new, open box unit available for $49. It was, as claimed, new, not used and returned.