Question about Mercury Mountaineer

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I am driving down the road and my car jumps then says it is in engine fail safe mode. I have to pull over to the side of the road, I turn my car off, then turn it back on. Once I start my car again it seems fine, however this has happened on three different occasions. My car is a 2004 Mercury Mountaineer

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Now you have to stop using it,sorry

You have two main Fail Safes
One is overheating

Without getting in a long technical story
the individual coils you have COP Ignition System,
either slowly fail and set no light,or set a code
In your case it doesn't matter because the codes won't help much

You most likely have a really bad ignition coil
It does not ground out as it should in the PCM (computer)
That spike comes back on the TPS Sensor (throttle position)
and then you lose the TPS normal Data that is the result
of where you push on the gas pedal

At that point there is no way to adjust fuel injector pulse,so
it starts killing cylinders and eventually goes into ETC Fail-Safe

Your Done-- Also there may not be many professionals that
will believe me. Been there done that.

Ideally a shop that actually uses an oscilloscope can solve
which coil is bad
You can buy 1 coil for $60.00 & walk it from one cyl
to the next and after a week fix it for $60.00

I will tell you, people have spent $3000.00 at dealers
& got zip.

In the event my story if off,
your next problem would be the
TACM (throttle actuator control motor )
That will be your codes. Do Not let the codes
guide you or your repair shop. The throttle body
is $700.00. If you do need one, you better be installing
your self.

Posted on Mar 31, 2011


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Posted on Jan 02, 2017


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