A/C Issues. Checked Fuses/Relays/Fan, What next?

[AEMalakai]

1.4L Turbo 2015 - 46k Miles - out of bumper to bumper warranty. No codes

AC stopped blowing cold when my wife was driving home. I checked the car and noticed that the radiator fan refused to turn on

1. Turning defrost, AC HIGH, does not kick the fan on
2. Using a AC manifold gauge the low pressure side is HIGH (gauge goes to max)
3. All j style fuses test fine. I've rotated fuses around just in case
4. All relays have tested fine. I've rotated relays as well.
5. Sending 12V to the fan causes it to run on high.
6. The harness that connects to the fan never shows a voltage
7. The A/C Clutch never engages.
8. Cabin air filter is new
9. Internal blower works

So whats next, Thermostat? My understanding is that I need to replace the entire housing.

Also I'm seeing conflicting guides on the location, is it to the left near the passenger side or to the right near the battery.

Second are Temperature senders. Are there two?

I also see two small relay like devices above the radiator fan, red in color, any idea what these are?

 

[AEMalakai]

update, swapped fuses even though it wasn't really needed.

Fan does turn on when car reaches around 220 degrees, and cools down.

So....... I'm at a loss right now on what to do next. From my understanding there should be a pressure sensor somewhere, and an expansion valve. Both can cause this. But replacing these would require evacuating the system.

 

[sonic-image]

1.4L Turbo 2015 - 46k Miles - out of bumper to bumper warranty. No codes

AC stopped blowing cold when my wife was driving home. I checked the car and noticed that the radiator fan refused to turn on

1. Turning defrost, AC HIGH, does not kick the fan on
2. Using a AC manifold gauge the low pressure side is HIGH (gauge goes to max)
3. All j style fuses test fine. I've rotated fuses around just in case
4. All relays have tested fine. I've rotated relays as well.
5. Sending 12V to the fan causes it to run on high.
6. The harness that connects to the fan never shows a voltage
7. The A/C Clutch never engages.
8. Cabin air filter is new
9. Internal blower works

So whats next, Thermostat? My understanding is that I need to replace the entire housing.

Also I'm seeing conflicting guides on the location, is it to the left near the passenger side or to the right near the battery.

Second are Temperature senders. Are there two?

I also see two small relay like devices above the radiator fan, red in color, any idea what these are?

The thermostat is very common to go on our cars, mine went in my old 13’, it was covered under GMs warranty as I did not have bumper to bumper either, however when mine went I got the code.
Not sure if this helps any, maybe a multi point inspection at the dealer could pick up some recalls or fix stuff under GMs powertrain warranty would be my two cents.


Sent from my iPhone using Tapatalk

 

[gnonne]

Change the thermostat and housing. It has the coolant temp sensor in it...

The thermostats can go bad slowly and NOT trigger a CEL or set any codes. Generally, this causes running cold problems, like not having the radiator fan run, no heat in winter, reduced MPG, etc.

Somehow, the computer is telling the A/C it can't engage. Not sure exactly why that is happening, maybe it thinks its cold and is running a rich mixture, then the computer says "no" to the compressor because it thinks the engine is under heavy load, but that's a total guess.

But the car is going to need a thermostat and housing at some point, so you may as well do it now while its not cold outside, drive it for a few days and see if things reset.

 

[wasteoffilm]

By any chance, does your outside air temperature display incorrectly? If the sensor in the lower grille is unplugged or damaged, the radio will display -40 degrees, and the A/C will be disabled.

Slightly concerned about the pressure reading maximum. Is there an actual number? From a quick look in my repair info, static pressure would be *roughly* 1psi per 1 degree Fahrenheit.

When active, which it isn't, would be between 22-54 psi depending on temperature and humidity, more=more.

There are two temp sensors, one at the thermostat, and another at the bottom of the radiator, passenger side. I had to change my radiator sensor last year, it was triggering a P00B6 trouble code, and once the radiator fan would engage, it would stick on high until I turned the car off.

Pressure sensor is located in the line coming off the top of the compressor.

 

[AEMalakai]

By any chance, does your outside air temperature display incorrectly? If the sensor in the lower grille is unplugged or damaged, the radio will display -40 degrees, and the A/C will be disabled.

Slightly concerned about the pressure reading maximum. Is there an actual number? From a quick look in my repair info, static pressure would be *roughly* 1psi per 1 degree Fahrenheit.

When active, which it isn't, would be between 22-54 psi depending on temperature and humidity, more=more.

There are two temp sensors, one at the thermostat, and another at the bottom of the radiator, passenger side. I had to change my radiator sensor last year, it was triggering a P00B6 trouble code, and once the radiator fan would engage, it would stick on high until I turned the car off.

Pressure sensor is located in the line coming off the top of the compressor.

Temperature sensor records correctly.

Just had a dealer diagnostic. They quoted me $1500 to replace the radiator. They claim its cracked and needs replacement. On a two year old car just out of bumper to bumper that hasn't been in an accident.

Don't know what to do right now. I can swap a radiator even though I know it will be a pain. But along with the radiator I will probably do the thermostat/water pump along with it.

Does anyone know if the A/C has to be evacuated when swapping the radiator?

Also wondering if I the dealer will give me crap about driving it home. It didn't overheat on the way there, would this affect my power train warranty at all? I've been burned in the past.

 

[AEMalakai]

Drove home.

The Service report says the following recommended

BG09 Fuel Induction Service $249
CS35 Radiator Replace $1405
AC001 AC evacuate and recharge (replace schreader valve) $270


So according to them the radiator is the cause of no AC and high pressure on the low side. Nothing makes sense to me. Ordered the radiator myself. Still researching whether or not I need to evacuate the system. The condenser should be separate.

 

[92dakota]

.. dosent make sence.. condenser maybe .. but rad? idk..

high pressure on low side... for gigglei just check my van , its over 90psi on low side has been sitting for 24 hours or so not running , when running drops to 35psi.. and that AC is brutal cold .. high side will equalize to low side, really common is compressor isn't running...

I would check my Sonic but its in transmission shop right now, got them to check the rad fan, seems fine, just not heating up enough as they commanded it and it ran..

 

[AEMalakai]

.. dosent make sence.. condenser maybe .. but rad? idk..

high pressure on low side... for gigglei just check my van , its over 90psi on low side has been sitting for 24 hours or so not running , when running drops to 35psi.. and that AC is brutal cold .. high side will equalize to low side, really common is compressor isn't running...

I would check my Sonic but its in transmission shop right now, got them to check the rad fan, seems fine, just not heating up enough as they commanded it and it ran..

The low side has so much pressure that the cap blew off. The schreader valve is bubbling nonstop.

 

[92dakota]

without knowing high side pressure, whats the max your gauge shows on low? 100 psi? 120? or like 70 like most..

 

[AEMalakai]

without knowing high side pressure, whats the max your gauge shows on low? 100 psi? 120? or like 70 like most..

I'll get another reading tomorrow. I do have a AC manifold gauge.

 

[AEMalakai]

Ok sorry this took so long, life sucks some times.

Here is a shot of the gauges. I've love to tell the low pressure psi but I cant as my gauge isn't accurate past 120psi.

High side was around 150 PSI.
Low side went past 120 PSI, below 350.
But my AC Pro gauge maxed out going to 150 PSI

I couldn't get the compressor to kick on.

In any case I found a leak at the thermostat housing. Second picture shows it. How is this part different from the thermostat?

I've already ordered the ACDelco Thermostat and DDMworks Silicone hoses. Once they arrive I'll pressure test the system and see if I can find further leaks. I have yet to find any leaks from the radiator itself even though the dealer said it was leaking near the top.

Most of the AC has vented from the bad schrader valve. I'll vacuum it down , replace the valve and recharge the system once I'm done with everything, still waiting on parts.

 

[AEMalakai]

Pressure tester arrives tomorrow. I've driven the car a few times, the only leaks are at the Water outlet housing, so I ordered one.

Pulled the part, it's not crushed or cracked but there is a definite dip in the tube. It either leaked from there or from the sensor. I'm considering flushing the dexcool out and running a different coolant, this stuff has left the hoses/gaskets looking nasty.

If the current radiator pressure tests fine then I'm going to be severely pissed at the dealer.

 

[92dakota]

hmm some reason my post never posted.. wth..

if AC has vented it possible air has gotten in and the reading is skewed from air, ive' seen this recently actually with a few vehicles.. but in those cases the compressor still engaged, just no cooling, dumped the system, was 99% air....

you can also try jumping the high or low switch (usually low side) and see if the compressor engages , my old neon i had to do this once to get it working then from there never had a problem, just low side pressure was so high it wouldn't allow it to engage..(car sat for 2 years untouched)

based on those readings the high side is going to be high, since it should balance out to around the 120~ ... can't give you specifics off my sonic atm since almost 3 weeks now its still in the blasted transmission shop.. but thats a whole other fiasco ..lol

 

[AEMalakai]

So I'm pissed. There is nothing wrong with the radiator, it is not leaking anywhere.

Replaced the water outlet (which should be covered by powertrain warranty). Replaced the hoses, replaced expansion tank, expansion tank cap, coolant and the A/C low side schrader valve.

Car no longer leaks coolant.

So the dealership quoted me $1500 to replace the radiator instead of actually diagnosing anything, why did I spend $150 on a diagnostic? Looking at the paperwork they did a pressure test because it was low on coolant. That's it.

I vacuumed down the AC port, and recharged with oil/R134. After starting the car I had cold air, for about 10 minutes....

Compressor kicked on and off like it was supposed to. AC manifold gauges were looking good, low speed Radiator fan was on, never noticed it go into high speed. When I restarted the car it stopped kicking the compressor on and the low side port started rising in pressure again. Taking the manifold off again I saw the schrader valve bubbling. No fuses are blown, relays are new and obviously working since it did work.

I have not yet replaced the thermostat. Doing that tonight.

 

[AEMalakai]

Attaching pictures.

Here you can see the vacuum test, it held -20~ psi for an hour.

AC manifold is back to the old problem of low side psi rising and compressor not coming on again.

 

[gnonne]

These are very sensitive AC systems and the cars are known to have t-stats that go bad without throwing any codes. For the past 2 weeks I've been driving an 18 yr old Buick that has really cold AC compared to any of my three Sonics. This is because the computer does not cycle the compressor off all the time on the older car.

In the Sonic, almost anything seems to shut off the compressor - step on the gas, compressor goes off, idle too long at a red light and computer leans it out to save gas, then shuts off compressor, if it thinks its running too cold, it shuts off the compressor... The only way to get really cold air out of any of them is in steady-state, low throttle driving.

 

[92dakota]

when its off low side will rise, that's normal as part of equalization.. after sitting almost 3 weeks not being used while transmission was rebuilt, got it back today, mine was 100~ on both sides.. fired up I was 35~ on the low and 150~ on the high

what was reading when it was running, if high side was over 150, either a restriction or overcharge.. low side should be in the 30 area..


as stated above, even my parents since new never had really cold ac unless constant driving.. but ive never heard it cycle on and off ever, unless on the throttle..

based on the *off not running reading* its overcharged

have you tried to jump the switch on the low pressure line? see if the compressor runs...

 

[AEMalakai]

when its off low side will rise, that's normal as part of equalization.. after sitting almost 3 weeks not being used while transmission was rebuilt, got it back today, mine was 100~ on both sides.. fired up I was 35~ on the low and 150~ on the high

what was reading when it was running, if high side was over 150, either a restriction or overcharge.. low side should be in the 30 area..


as stated above, even my parents since new never had really cold ac unless constant driving.. but ive never heard it cycle on and off ever, unless on the throttle..

based on the *off not running reading* its overcharged

have you tried to jump the switch on the low pressure line? see if the compressor runs...

No I haven't where is the switch located?

 

[92dakota]

usually between the charge port and firewall cant miss it, big switch with a wire on the line, highside has one aswell usually closer to the condensor on the tiny line..

but if you want direct , have to wait till i get home form work.. wife wont let me take the car.. haha