While in the grand scheme of things, 5 seconds isn’t all that long, its longer that you may think. To help you out with your sense of time, take 5 seconds and watch this.
Q: Why do the engine lights keep coming on in the chassis?
A: 60% of all engine light problems result from an incomplete ECM system check.
What is an ECM system check? And why does this happen?
The ECM in the engine has to identify all of the sensors in the chassis; it has to look for each address and then recognize it and ensure that its functioning properly. This process takes about 5 seconds. These days, we are so accustomed to immediacy that waiting for 5 measly seconds seems like an eternity. You may hear some clicks and clacks but this is just the process going through its motions; even the gauges in the instrument panel undergo a sweep.
If we jump in the cab and just start the truck, the ECM is unable to complete its check and not only will the check engine light stay on, but often times this will result in a fault code being sent to the engine inhibiting the engine from running at full power. So if your truck was running fine yesterday but seems sluggish today, you need to be sure to wait the :05 seconds and let this sweep complete.
There, simple as that. Tick tock.