PCM reset before every start? why?
04-16-2005, 07:59 AM
#1
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Location: California (san fernando valley)
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PCM reset before every start? why?
I posted this in the Mods section but no replies there so I think I am in the right place now....
.
It happens every 2 to 3 days but when I want to use my ac it wont work. It blows out hot air even if the temp **** is as far to the left as it goes
.
I dont hear the compressor click and the low speed fan does not come on as it is supposed to when you turn the ac on so what i have to do is shut the car off, pull the PC BAT 10amp fuse for 10 sec and then plug it back in and everything works back to normal again
.
Sometimes even while driving with the ac on the air starts to get hot and next thing I know the low speed radiator fan is no longer blowin through so I have to do the same process all over again....
.
does anyone know whats causing this>?
THANKS IN ADVANCE!~
.
It happens every 2 to 3 days but when I want to use my ac it wont work. It blows out hot air even if the temp **** is as far to the left as it goes
.
I dont hear the compressor click and the low speed fan does not come on as it is supposed to when you turn the ac on so what i have to do is shut the car off, pull the PC BAT 10amp fuse for 10 sec and then plug it back in and everything works back to normal again
.
Sometimes even while driving with the ac on the air starts to get hot and next thing I know the low speed radiator fan is no longer blowin through so I have to do the same process all over again....
.
does anyone know whats causing this>?
THANKS IN ADVANCE!~
04-19-2005, 12:47 PM
#5
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Location: Middle Tennessee
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Re: PCM reset before every start? why?
Isn't the PCM looking for a certain pressure in the lines before it turns on the compressor?
Maybe there's a sensor that needs to be replaced. What's the deal on the passenger side of the engine bay near where a strut bar mounts do? It's got wires that go to it, if that's faulty, I wonder if it would create your problem.
Maybe there's a sensor that needs to be replaced. What's the deal on the passenger side of the engine bay near where a strut bar mounts do? It's got wires that go to it, if that's faulty, I wonder if it would create your problem.
04-19-2005, 01:57 PM
#6
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Re: PCM reset before every start? why?
Hmm...well i am pretty sure the pressures are ok because once i remove the fuse and plug it back in it will work fine and cool air comes out...
WIll a scan possibly find the faulty sensor? It should right if it has failed?
WIll a scan possibly find the faulty sensor? It should right if it has failed?
04-24-2005, 12:32 PM
#8
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Re: PCM reset before every start? why?
Originally Posted by LWillmann
Not necessarily..
IF the switch is stuck, then maybe resetting the PCM lets it reset as well.
Not likely on the scan finding the fauly sensor for the AC.
IF the switch is stuck, then maybe resetting the PCM lets it reset as well.
Not likely on the scan finding the fauly sensor for the AC.
Yeah...thats very true....
It has not done it for some days now so I dont know if it fixed itself or its just waiting for me to forget about....its like it knows what I am thinking and
fails on me on the worst times
.....Hmm...not a car expert here...I dont even know where to start anymore besides pulling the fuse out everytime that happens...
.
04-25-2005, 08:45 AM
#10
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Location: Middle Tennessee
Posts: 1,831
Re: PCM reset before every start? why?
An SES light doesn't always mean the car is in limp home mode. Limp mode is usually reserved for severe failures if I remember correctly.
BoobSter-lt1-z: Make sure there is a good connection at the pressure sensor on the hard AC line over the passenger side fender well. There are two wires that go to it, might try disconnecting it, checking the contacts (cleaning if needed) and reconnecting. That's the only thing I can think of.
There may be a evaporator temp sensor as well. In Autotap (for my 96) it says that this sensor is what the PCM uses to cycle the compressor clutch. So, if this sensor is bad or failing, it might be causing your problem. As for the location of that sensor, I'm not sure.
BoobSter-lt1-z: Make sure there is a good connection at the pressure sensor on the hard AC line over the passenger side fender well. There are two wires that go to it, might try disconnecting it, checking the contacts (cleaning if needed) and reconnecting. That's the only thing I can think of.
There may be a evaporator temp sensor as well. In Autotap (for my 96) it says that this sensor is what the PCM uses to cycle the compressor clutch. So, if this sensor is bad or failing, it might be causing your problem. As for the location of that sensor, I'm not sure.
04-25-2005, 10:08 AM
#11
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Re: PCM reset before every start? why?
Good to know....
I dont know where these parts are but I will take a look on Shoebox's website or try a google search or my Haynes manual and see what I can find. Ill also
trace the wiring....since the day I posted this it has not failed since so I dont know what is going on but I'll look for any loose ground wires
and check connections...
THANKS A LOT!!!!!!
I dont know where these parts are but I will take a look on Shoebox's website or try a google search or my Haynes manual and see what I can find. Ill also
trace the wiring....since the day I posted this it has not failed since so I dont know what is going on
but I'll look for any loose ground wiresand check connections...
THANKS A LOT!!!!!!
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