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A/C Problems

Messages
59
Likes
35
Location
Huntington Beach
#1
Today I went to turn on my air conditioning because I was sitting in the 80* Sun, and my vents just blew ambient air. I’ve checked all my fuses and relays, and they’re all good. I don’t see my RPM’s rise and I don’t hear the compressor come on. I tried reflashing my ECU to factory by Uninstalling my AP. Nothing. Tried reinstalling my different tunes. Nothing. I tried pulling my Negative lead to my battery. Nothing let me know what you think it could be because I’m at 47K now and don’t feel like paying the Dealership $1000+ to fix my 1 year old Fiesta.
 


felopr

Senior Member
Messages
815
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370
Location
JD
#2
Today I went to turn on my air conditioning because I was sitting in the 80* Sun, and my vents just blew ambient air. I’ve checked all my fuses and relays, and they’re all good. I don’t see my RPM’s rise and I don’t hear the compressor come on. I tried reflashing my ECU to factory by Uninstalling my AP. Nothing. Tried reinstalling my different tunes. Nothing. I tried pulling my Negative lead to my battery. Nothing let me know what you think it could be because I’m at 47K now and don’t feel like paying the Dealership $1000+ to fix my 1 year old Fiesta.
It happend 2 times for me, 1 time it went away on his own, the second one i erased the KAM memory (if you have accessport you can do it from there) and it went away.
The common denominator both times when it happend was that i turn the vehicle off with the air on.
this is not a fact but only my opinion so take it with a grain of salt, is that sometimes if you turn the vehicle off with the AC on, the AC control module goes haywire. you could try what i did, install the AP on whatever stage, go and reset the KAM (keep alive memory) see if that helps.
or try, push the start button but dont start the engine, cicle on and off the AC, press the push to start button and open the door to shut the vehicle down , then start the car normally, see if that helps
 


KnockOff

1000 Post Club
Messages
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450
Location
Menifee
#3
Happened to me twice. After starting the car again it worked fine both times. Hopefully it won't do it again.

Sent from my SM-G930P using Tapatalk
 


OP
JorJorBinks
Messages
59
Likes
35
Location
Huntington Beach
Thread Starter #4
No Dice with either of those methods. I think at this point I’d be more worried if it fixed itself. Haha next step will be using a multimeter and see if the clutch is getting power.
 


me32

1000 Post Club
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1,829
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Location
fairfield
#5
What year so you have. I thought there was a tsb for some 15 and 16 models
 


OP
JorJorBinks
Messages
59
Likes
35
Location
Huntington Beach
Thread Starter #8
I found a few TSB’s regarding my issue. How would you recommend me going about resolving this problem? This is the first I’ve heard of a TSB. I’ve had to bring my car in for the clutch pedal and a window actuator both were covered under warranty. So that’s what I’m going off of.
 


Messages
60
Likes
15
Location
Temple Terrace
#9
Could be worse... my AC compressor froze at 37k miles. Burned the belt and 2 of the pulleys and almost instantly over heated the car since the water pump runs on the serp belt. But it’s a ford thing, I’m used to things going wrong that should never be an issue.
 


Messages
407
Likes
75
Location
Wichita
#10
I found a few TSB’s regarding my issue. How would you recommend me going about resolving this problem? This is the first I’ve heard of a TSB. I’ve had to bring my car in for the clutch pedal and a window actuator both were covered under warranty. So that’s what I’m going off of.
Take it in they will do a re flash which might fix it. Known issue with at least the 16 model year
 


OP
JorJorBinks
Messages
59
Likes
35
Location
Huntington Beach
Thread Starter #11
Ok gotcha! Last question, should I remove any mods I’ve done? I’ll uninstall my AP just for obvious reasons, but I’ve got the COBB stage 2. Should that be an issue?
 


Messages
407
Likes
75
Location
Wichita
#12
I just took my AP out of the car and said my car is doing this and can they do the tsb and they did it. Took about 20 mins if I correctly
 


jeff

2000 Post Club
Messages
2,309
Likes
3,220
Location
Evans
#13
Today I went to turn on my air conditioning because I was sitting in the 80* Sun, and my vents just blew ambient air. I’ve checked all my fuses and relays, and they’re all good. I don’t see my RPM’s rise and I don’t hear the compressor come on. I tried reflashing my ECU to factory by Uninstalling my AP. Nothing. Tried reinstalling my different tunes. Nothing. I tried pulling my Negative lead to my battery. Nothing let me know what you think it could be because I’m at 47K now and don’t feel like paying the Dealership $1000+ to fix my 1 year old Fiesta.
It happend 2 times for me, 1 time it went away on his own, the second one i erased the KAM memory (if you have accessport you can do it from there) and it went away.
The common denominator both times when it happend was that i turn the vehicle off with the air on.
this is not a fact but only my opinion so take it with a grain of salt, is that sometimes if you turn the vehicle off with the AC on, the AC control module goes haywire. you could try what i did, install the AP on whatever stage, go and reset the KAM (keep alive memory) see if that helps.
or try, push the start button but dont start the engine, cicle on and off the AC, press the push to start button and open the door to shut the vehicle down , then start the car normally, see if that helps
Thanks for this. How do you reset the KAM using the Accessport? Is it the same as resetting the ECU under the "Troubleshooting" option?

Could be worse... my AC compressor froze at 37k miles. Burned the belt and 2 of the pulleys and almost instantly over heated the car since the water pump runs on the serp belt. But it’s a ford thing, I’m used to things going wrong that should never be an issue.
Mine died at 7k. They fixed it under warranty. It works mostly but I've noticed if I push the A/C button (vents on, compressor off) and then try to reengage it, it does not work, or takes several minutes before it begins blowing cold. Kinda sucks...my 1998 Civic beater with 200,000 miles has ice cold A/C with no problems ever. Fiesta currently has 24k.
 


felopr

Senior Member
Messages
815
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370
Location
JD
#14
Thanks for this. How do you reset the KAM using the Accessport? Is it the same as resetting the ECU under the "Troubleshooting" option?



Mine died at 7k. They fixed it under warranty. It works mostly but I've noticed if I push the A/C button (vents on, compressor off) and then try to reengage it, it does not work, or takes several minutes before it begins blowing cold. Kinda sucks...my 1998 Civic beater with 200,000 miles has ice cold A/C with no problems ever. Fiesta currently has 24k.
There should be a reset keep alive memory or kam under the accessport troubleshooting
 


Messages
118
Likes
17
Location
Mooresville
#15
It’s the AC compressor motor or something. Mine was brand new 2016 and it blew out at 120 miles. It should be under warranty.
Edit: keep the accessport and mods on. I don’t think it affects warranty. It only voids when you’ve altered it.
 


KnockOff

1000 Post Club
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1,348
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450
Location
Menifee
#16
Some dealers don't like tunes. Besides it only takes 5 min to do. For a dealer to refuse a warrenty claim based on a mod they must have proof the mod caused the failure. As far as I know there is not a mod that bust' s ac units.

Sent from my SM-G930P using Tapatalk
 


Intuit

3000 Post Club
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Location
South West Ohio
#17
No Dice with either of those methods. I think at this point I’d be more worried if it fixed itself. Haha next step will be using a multimeter and see if the clutch is getting power.
You'll want to check and see whether the ECU is signaling the A/C clutch relay. In my prior vehicle, the ECU was signaling the relay, but the relay never engaged. Bad relay. Another tell-tale that it was the relay, was the fact that the engine idled up in anticipation of the missing load. So it would idle at ~1800 RPM instead of 800.

If the ECU isn't signaling the relay, then you have to consider what logic may be preventing the ECU from engaging the clutch relay; low pressure (loosing freon) or near freezing ambient temps for example. It is normal for compressors not to engage when it is near freezing. I believe this might be a function of the pressure switches and not some independent sensor.
 


OP
JorJorBinks
Messages
59
Likes
35
Location
Huntington Beach
Thread Starter #18
I tried a new relay from O’Reileys that was close to being the correct relay but wasn’t exactly the same and nothing happened. Also when I turn my MAX A/C on the high speed fan comes on for a second or two then shuts off. I checked the low pressure side of the pipping and it was at 0. Lol I’m assuming this is because the pump wasn’t running.
 


Intuit

3000 Post Club
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Location
South West Ohio
#19
Relays are generally pretty reliable. Replacing the part without checking to confirm that it was being signaled, qualifies as "throwing parts at it". That said, in one case and also on a different vehicle, the relay was being signaled, but with insufficient voltage to trip the coil. (bad wire harness between ECU and relay) In another case, the ECU was signaling the relay but the relay had a very weak link to ground. (discovered via measuring resistance) These cases were all in vehicles that were relatively old at the time. (>10 years)

But my point is, we can't assume anything and just start replacing parts. Once you confirm that the relay isn't being signaled, you'll need to check both high and low side pressures with the proper gauging and compare those readings to specification for the given ambient temps. Some folks have access to those specifications and will provide them if you post your numbers. While refrigerant leaks aren't nearly as common as they used to be, that's probably the easiest and best place to start your checks with most A/C doesn't engage type issues.
 


me32

1000 Post Club
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Location
fairfield
#20
I found a few TSB’s regarding my issue. How would you recommend me going about resolving this problem? This is the first I’ve heard of a TSB. I’ve had to bring my car in for the clutch pedal and a window actuator both were covered under warranty. So that’s what I’m going off of.
Take it in. If your in your 3 yr 36k it will be covered under warrenty. Remove your tune. They may update the pcm
 


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