Engine Light On
This has happened before and I told the Ford dealer about it and they told me "don't worry and just reset it"
Is this something that should worry me? or on the odd occasion that it happens just reset it?
Thanks!
As to the "don't worry and just reset it". No. Don't do that. When a problem turns on the malfunction indicator light -MIL (alternatively known as the check engine light -CEL) it means something that affects the engine emissions is out of spec. Most potential problems have a requirement for the fault to occur over a time period or a number of drive cycles. This helps to keep false data from turning on the light. For example, in a gas engine, if every time the engine misfired, you wouldn't be able to make it around the block without the MIL coming on. So the computer is looking for this fault to repeat in a pattern before it turns on the light. So, the MIL is on and you can be pretty sure it is because the computer is convinced there's a problem. What happens is the computer holds all of the sensor data at the moment it turned on the MIL. This is called freezeframe data and is very useful in helping to discover if you have a sensor problem or a real system problem. When you erase the computer to turn off the MIL, you are removing the code data and the freezeframe data. Now there isn't anything for anyone to look at to help diagnose the problem. Of course, if you aren't going to get it fixed, then you don't need data. But if the problem is an intermittent sensor fault, the criteria that turned on the MIL will also turn it off so you don't really need to do anything. Now here's the most important part and what tells me the person at the dealership who told to to reset the light is an idiot and not a technician: Resetting or clearing the code doesn't fix anything. The computer isn't reset as it would be in a reboot since there's nothing wrong with the computer. That's not where the problem is. The computer is just telling you about bad news in the system. It would be like you go online to check you bank account and then smashing your laptop because you overdrew your checking account. So, clearing the code to turn off the MIL just clears the computer data. No fix for the problem.
So, when the MIL comes on, you first plug in a scanner, read the code(s) and interpret their possible meaning. Then decide what you're going to do about it. Some codes will put you on the side of the road and demand your immediate attention.
As to the "don't worry and just reset it". No. Don't do that. When a problem turns on the malfunction indicator light -MIL (alternatively known as the check engine light -CEL) it means something that affects the engine emissions is out of spec. Most potential problems have a requirement for the fault to occur over a time period or a number of drive cycles. This helps to keep false data from turning on the light. For example, in a gas engine, if every time the engine misfired, you wouldn't be able to make it around the block without the MIL coming on. So the computer is looking for this fault to repeat in a pattern before it turns on the light. So, the MIL is on and you can be pretty sure it is because the computer is convinced there's a problem. What happens is the computer holds all of the sensor data at the moment it turned on the MIL. This is called freezeframe data and is very useful in helping to discover if you have a sensor problem or a real system problem. When you erase the computer to turn off the MIL, you are removing the code data and the freezeframe data. Now there isn't anything for anyone to look at to help diagnose the problem. Of course, if you aren't going to get it fixed, then you don't need data. But if the problem is an intermittent sensor fault, the criteria that turned on the MIL will also turn it off so you don't really need to do anything. Now here's the most important part and what tells me the person at the dealership who told to to reset the light is an idiot and not a technician: Resetting or clearing the code doesn't fix anything. The computer isn't reset as it would be in a reboot since there's nothing wrong with the computer. That's not where the problem is. The computer is just telling you about bad news in the system. It would be like you go online to check you bank account and then smashing your laptop because you overdrew your checking account. So, clearing the code to turn off the MIL just clears the computer data. No fix for the problem.
So, when the MIL comes on, you first plug in a scanner, read the code(s) and interpret their possible meaning. Then decide what you're going to do about it. Some codes will put you on the side of the road and demand your immediate attention.
I did a bit more research and found that Ford issues a bulletin on this issue!!!
I've contacted the dealer and asked them for next steps.
Attaching the bulletin :-)
Thanks Again!





