What would cause the pcm to loss data

[tmikes]

Trying to get my 97 mercury mountaineer V8 to pass smog I replaced the battery last year but the PCM keeps resetting it self every time I turn the vehicle off which causes it to fail do to monitors not ready. What could be the cause ?

 

[C420sailor]

There’s a wire that’s always hot. I believe it’s a yellow wire called ‘keep alive power’.

Figure out what fuse feeds that. If the fuse checks good, trace it from the PCM to the battery.

 

[1998Exp]

Looks like the 'keep alive power' connection is broken. On my '98 it goes through fuse #6 (10A) in the power distribution box (under the hood). It may or may not be the same fuse in yours - check your manual.

 

[tmikes]

Ok thanks for the info. I check my horn and it does not work so am thank I will check the fuse and yellow wire this weekend and report back