hello guys,i was watching paul video Chrysler Sebring 2.4L No Start (headlight circuit shorted to sensor ground)Part 3 ,,and i dont understud,how can we cook computer with just sending power to etc sensor ground? is there any protection in computer?to avoid this,,
by the way what hepend if i Reserve batery conections? can i cook computer?
The headlight circuits power was shorted to the ambient sensors ground as this ground had 12v on it when the headlights were on. A short directly to ground has no load which would fry the computer.
I assume that some of the circuits on an ECM are protected. The problem is that we do not get that information so have to assume that it could get damaged. It all depends on how the computers are designed and since there are so many makes and models along with what year, there is too many variables.
Think of it this way, is your home computer or the computer that you are currently working on have it's own internal protection for substantial power surges? I highly doubt it.
The following user(s) said Thank You: Noah, qwefdref
Moved this thread also to video/book questions and discussion. If you don't have a specific repair question about a vehicle don't put it in 'post your repair questions here' Andyy Thx.
A temperature sensor ground is designed to handle about 0.01 amps max --- an headlamp unit load is about 10 amps with main beam on for each side.
With temperature sensors the 5v supply passes through an internal resistor witin the PCM before it goes to the sensor. The the PCM internal resistor and the sensor form a potentiometer style circuit --- that divides the 5v ref. Although it measures 5v on a DVOM when disconnected the 5 v side of of temperature sensor isn't a true 5v ref because it has passed through a resistor within the pcm
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Thx. 
