Defroster turned on by itself

[seasprite]

Hey all,
Driving to work today my defroster kicked on 3 different times on my to work today, and once on the way home. Have any of you ran into this and what was the outcome?

I did run Forscan scanner and green across the board. So I ran the self test on the FCIM and it passed, so I did a FCIM Module reboot. Don't know what to do from this point on. Hopping the reboot got rid of the gremlin. Won't find out until tomorrow though.

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[RangerBill]

Was your HVAC set to Auto? Was it set to off?

 

[Big Blue]

Hey all,
Driving to work today my defroster kicked on 3 different times on my to work today, and once on the way home. Have any of you ran into this and what was the outcome?

I did run Forscan scanner and green across the board. So I ran the self test on the FCIM and it passed, so I did a FCIM Module reboot. Don't know what to do from this point on. Hopping the reboot got rid of the gremlin. Won't find out until tomorrow though.

What was the weather like, was it humid out at the time?
If your HVAC was in auto it may divert the air to the windshield and increase the air flow to prevent fogging if the inside and outside temps and humidity may cause it. It will even cycle the A/C and heat to dry out the air. Depending on conditions your HVAC may have been working as designed.

I tend to set a temp and leave mine in AUTO. Usually don't need to touch it, but then I'm pretty easy going. ?

 

[Grumpaw]

Hey all,
Driving to work today my defroster kicked on 3 different times on my to work today, and once on the way home. Have any of you ran into this and what was the outcome?

I did run Forscan scanner and green across the board. So I ran the self test on the FCIM and it passed, so I did a FCIM Module reboot. Don't know what to do from this point on. Hopping the reboot got rid of the gremlin. Won't find out until tomorrow though.

 

[Msfitoy]

Irreverent, I tell ya...

 

[seasprite]

Its manual
I just got back from Wednesday prayer service and it did it again. Since I reset the module the only things that lit up on the control panel was the power light and first blower setting. Its a nice day here so I haven't selected a mode yet and probably why no other lights came on, on the control panel.
Before when the defroster came on I believe this was the last thing I used and why those lights came on for the defrost.

Wondering if I have a wire touching somewhere it shouldn't be giving it the command signal to come on.

 

[Grish]

Let me know what you find out. mine does it too. Can be a nice day with windows down and boom. Kicks on for no reason. No auto setting on mine either.

 

[airline tech]

To confirm - You had the system - Off and it powered on (automatically)
and
It cycled off and back on (automatically) or you selected it back off and it (repeatedly turned itself back on)?
Hmm - I know the weather was nice but the humidity was high due to all the recent rain 75%.

As far as I know, the humidity temp sensor input cannot turn the system on (automatically) if reading a high humidity.
I would be curious if it would do the same if turned off when a different last selected mode was used and what mode it powers on (automatically) - last or defrost?

My initial thought is the button input is sticking and the FCIM is picking up the button is being pressed.

 

[seasprite]

To confirm - You had the system - Off and it powered on (automatically)
and
It cycled off and back on (automatically) or you selected it back off and it (repeatedly turned itself back on)?
Hmm - I know the weather was nice but the humidity was high due to all the recent rain 75%.

As far as I know, the humidity temp sensor input cannot turn the system on (automatically) if reading a high humidity.
I would be curious if it would do the same if turned off when a different last selected mode was used and what mode it powers on (automatically) - last or defrost?

My initial thought is the button input is sticking and the FCIM is picking up the button is being pressed.

Yep, the system would turn on with no input from me then I would turn it off and few minutes would go by and it would turn on again.
I might take Forscan with me today and see what PIDs the FCIM has. Of course its raining and don't want to get my laptop hosed.
I think I'll go out right now and see what Pids I have. Be back in a few.

 

[seasprite]

No PID data in Forscan for the FCIM
But I did end up with a code today but I'm thinking it was from when I did module reset.
The code is from PAM and is an invalid data received from the FCIM and not present at this time (history)
U0557:00-28

 

[airline tech]

When it does it again - note when it cycles (off) are the Airbag lights (Illuminated)
and also try cycling the (ASS) switch - do you get a response from it?

To isolate if the (Ignition Switch) input or panel power is dropping and when it regains power it powers itself on (not remembering last positions) or if is strictly on the (Climate Switch) power.

 

[Blue Streak]

Ok I will admit I have had this issue. Thought I had a ghost in the truck turning it on. I have a 19 XL STX manual A/C. Mine would power on but did not turn on a function as defrost, heat, vent location dash or floor, just power & first fan speed. Turn it off manually then it would suddenly come on again. What I have tried ( so far it has worked but I have just done this the other day & don't have a lot of drive time on this approach) I used a electronics duster. Sprayed in around the power button real good. This may not bee the cure but so far so good. ?

 

[seasprite]

Alright, well today I thought I might get lucky and it would be a glitch and never return. Not to be about at the 20 mile mark of my drive in to work the climate control powered up. Before I left home I preset the settings to panel and speed level 3 on the blower then turned off the power. All buttons worked including ASS( I disabled Ass 3 years ago when I got the truck with Forscan) the light on the button and dash would display the status of ASS.

On the way home I decided to see if the FCIM would turn off the climate control if it was on, on the way home from work and it stayed on the entire time home.

So it only powers on when its off and won't power down if its on. Starting to look like a corrupt module.

Ok I will admit I have had this issue. Thought I had a ghost in the truck turning it on. I have a 19 XL STX manual A/C. Mine would power on but did not turn on a function as defrost, heat, vent location dash or floor, just power & first fan speed. Turn it off manually then it would suddenly come on again. What I have tried ( so far it has worked but I have just done this the other day & don't have a lot of drive time on this approach) I used a electronics duster. Sprayed in around the power button real good. This may not bee the cure but so far so good. ?

Sounds like a good thing to try. I don't have any electronics duster, but I do have compressed air. I'll give it a try.

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