Reset CEL after suspected repair or not?

Question

Assume I get a CEL and I determine the code and perform the re[pair/replacement of what I suspect to be the most likely cause. At that time, is it better to reset the CEL [erase the code(s)] and wait to see if the engine, after some miles (usually around 100) still does not throw CEL or should I leave it and wait for it to turn itself off? Or does this actually depend on the vehicle.

Another way to ask this would be: once the CEL is on, does the ECU perform checks on the sensor to see if the data collected indicate it should be turned off or does it actually need to be reset manually?

Answer 1

It has always been my practice to clear codes after a fix has occurred. Don't wait for the ECU to turn out the light on its own. In most cases, the ECU can turn out the light, however it may take a while for it to do so which means you'll be guess as to whether your fix was successful or not.

Another way to ask this would be: once the CEL is on, does the ECU perform checks on the sensor to see if the data collected indicate it should be turned off or does it actually need to be reset manually?

Bottom line is, you don't have to wait for it to turn off (and I wouldn't as stated above), but the ECU will most likely turn it off once it has done the checks it needs to to see that it's no longer an issue (dependent upon the actual code).