# HELP! No AC and multiple codes



## Tomko (Jun 1, 2013)

Was the negative battery ground cable ever changed?


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## snowwy66 (Nov 5, 2017)

How and where did you buy your ethos?


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## Cepromotion (Dec 10, 2012)

Tomko said:


> Was the negative battery ground cable ever changed?


Negative. These codes were also not here 1k miles ago when I changed the oil. I always scan for codes, and reset service interval properly.


Snowy - I got it at a great price during a promotion from my Snap-On Vendor at work, during xmas.. and paid for it out of pocket and took it home.


Alright, so some other symptoms I have that may ring a bell for someone that has had or seen this issues in the shop.


The AC Compressor is running (clutch is engaging)
The AC Switch is working (enabled with ethos, checked voltage on all AC fuses)
The Cooling Fan *is not* running with AC on High, but I can enable the fan *manually* via the ethos. It rarely heats up to the temperature at which the fan is needed without AC, so I have not found if it will run at a high temp yet.
Checked all fuses for the AC and the Cooling Fan. Tested Cooling Fan Relays 1,2,3 via ethos.
AC High Pressure Sensor is not steady; it's jumping around from 87-97 psi with no specific order. I have not located the High pres sensor yet to visually inspect/diagnose it.


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## Blasirl (Mar 31, 2015)

Have you tried resetting all of the codes and see if they all return?

*Special Coverage #14311: Negative Battery Cable

**2013 Cruze A/C off due to high engine temp

*P0533 means the A/C refrigerant pressure is too high to safely function *often due to inoperative cooling fans* or too little or too much refrigerant.






0r maybe this video

*FIXING OF RADIATOR FAN FULL BLAST IN A CHEVY CRUZE 2012 THERMOSTAT REPLACEMENT*


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## snowwy66 (Nov 5, 2017)

The Radiator fan don't work until high pressure gets high enough on the ac. Same manner as it works when your coolant temp gets high enough. Basically only when your sitting at idle. Fan not needed when driving down the road. 

Compressor running and high pressure is only 87 - 97. That's your answer right there. You're almost out of freon. High pressure should be around the 250 mark. The reason it's bouncing around is because the low pressure switch is cycling the compressor. Low pressure too low. That be my guess anyways but I'm not there to see what you got going on. 

I would slap on some gauges to verify though. Make sure the sensor to the computer is reading accurate. 

An accurate diagnosis of the system requires knowing what both the low AND the high are doing. Harbor Freight sells a good gauge kit for $60. I bought my last set on the july 4th sale 25% off. There are adaptors fair cheap at any store that sells freon in those cans. I buy the 30 lb. cylinders. 75% cheaper then buying enough cans to equal 1 cylinder. But I have a NAPA connection.

Since you have a high pressure gauge with your ethos. A kit of gauge and can will work for the low side,. 

You'll have to let me know the price of ethos at christmas time this year. I"d like to have a more comprehensive software package over the usual basic stuff commonly available. 

I bought toad. It's cheap. And a few happy campers on youtube but I"m not seeing it with the software. See what happens when the obd2 connector arrives. But I have a feeling it was a waste of $130.


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## Cepromotion (Dec 10, 2012)

Blasirl said:


> Have you tried resetting all of the codes and se if they all return?
> 
> *Special Coverage #14311: Negative Battery Cable
> 
> **2013 Cruze A/C off due to high engine temp*


Yes, I reset the codes and I have not seen them return. I also haven't spotted a leak anywhere.



> The Radiator fan don't work until high pressure gets high enough on the ac. Same manner as it works when your coolant temp gets high enough. Basically only when your sitting at idle. Fan not needed when driving down the road.
> 
> Compressor running and high pressure is only 87 - 97. That's your answer right there. You're almost out of freon. High pressure should be around the 250 mark. The reason it's bouncing around is because the low pressure switch is cycling the compressor. Low pressure too low. That be my guess anyways but I'm not there to see what you got going on.
> 
> ...




Yeah, I have been looking in my garage for my AC gauges but haven't used them in so long and cannot remember if I loaned them out or something... my Z28 doesn't have air and I am used to it that way.. so I suppose I will have to buy a new set of gauges to really continue diagnosis. Going to lift it up and look for leaks again and verify the AC High Pressure sensor is working correctly with the AllData manual I just downloaded.

Any idea if the compressor control valve can stop the AC from working, even if the clutch is turning? Seems like this would cause damage to the compressor since it would be running dry/choked off.



/edit - Oh and if you PM me I will tell you what the price was during the promotion. I can put you in touch with my vendor if you wish.


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## Blasirl (Mar 31, 2015)

Cepromotion said:


> Yes, I reset the codes and I have not seen them return. I also haven't spotted a leak anywhere.


That's odd. Have you turned on the AC since?


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## Cepromotion (Dec 10, 2012)

Blasirl said:


> That's odd. Have you turned on the AC since?



Yeah, the AC off due to engine temp never showed it's face.. It wasn't in the history codes either.

Yes, I have turned the AC on since. The compressor kicks on, the air is running but it's hot and not getting any cooler. Everything cycles and seems to be working. The PCM is also showing it's requested and enabled.. but no error codes are back yet.


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## Blasirl (Mar 31, 2015)

Cepromotion said:


> Yeah, the AC off due to engine temp never showed it's face.. It wasn't in the history codes either.
> 
> Yes, I have turned the AC on since. The compressor kicks on, the air is running but it's hot and not getting any cooler. Everything cycles and seems to be working. The PCM is also showing it's requested and enabled.. but no error codes are back yet.


Seems like your narrowing it down to low "Freon"

*DIY Bone chilling AC*


As @snowwy66 recommended:

*A/C R134A Manifold Gauge Set*


20% off coupon good today

More active longer


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## Cepromotion (Dec 10, 2012)

The AC High pressure sensor is changing while the car is off, power on. I did all the diagnostics and everything passed up until the "Diagnose/Replace B1 AC High Pres Sensor" So the circuit is good, it's either the sensor or the actual PSI on the system is wrong. Don't get why the pressure would be jumping around while the car is off though.

The P0533 S0 is Sensor Circuit High; yet the sensor is reading low and jumping


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## ChevyGuy (Dec 13, 2014)

Cepromotion said:


> Any idea if the compressor control valve can stop the AC from working, even if the clutch is turning? Seems like this would cause damage to the compressor since it would be running dry/choked off.


Keep in mind the compressor is a variable displacement type. How much it can "throttle back", I don't know.


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## snowwy66 (Nov 5, 2017)

Cepromotion said:


> Yes, I reset the codes and I have not seen them return. I also haven't spotted a leak anywhere.
> 
> 
> 
> ...


If you find your gauges or buy some gauges. A full charged system will sit at around 110 on both hi and low when it's sitting. 

What's your high pressure reading on your ethos with the car having been off for a couple of hours????????

When it's running. Fully charged will clock in around 250 on hi and you should have 30 - 35 on low. If everything is working properly. 

If you're that low though, I'd go ahead and have it sucked out with a machine. Then vacuum it and fully charge it. 

If you have access to a scale to measure the amount and label on your car still to tell you how much. That way you know how much to put in. YOu should end up around the 250 mark. They always end up around that mark. No matter what car or brand. 

FIRST. If you have a leak detector or can come up with one. Check the evaporator. Turn fan on high and sniff the vents. WITH CAR ENGINE OFF.


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## Cepromotion (Dec 10, 2012)

So..went and ggauges and theyre reading 0psi... why would the ac high pees sensor see 100psi but none at port.. wtf


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## snowwy66 (Nov 5, 2017)

Either you forgot to open the valves on the quick disconnects if you have them or your gauges are broken. The hoses themselves also have shrader valves. Something is wrong with your gauges. 

Here's a link to explain how the compressor control valve works. 

https://macsworldwide.wordpress.com/2013/05/29/variable-displacement-ac-compressor/


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## Cepromotion (Dec 10, 2012)

Nah, i hit the schrader on hi and lo port with a pin and no pressure. It must have a monster leak somewhere or something.. but why read 100psi?


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## snowwy66 (Nov 5, 2017)

Make up your mind. 

Is the compressor running or not? LOL

Cuz it can't run without at least 50 psi on both hi and lo. 

The low pressure switch kicks on at 50 and shuts off at 10.

You said it was running. But now you say nothing comes out with the push of a pin.


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## Cepromotion (Dec 10, 2012)

Yes sir, the compressor is running, clutch engaged. The pressure switch is reading 87-97psi at idle and when running; but the ports are reading 0psi and also not firing off any pressure when the schrader is depressed.


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## snowwy66 (Nov 5, 2017)

When charging ac and diagnosing pressures. Engine should be at 2000 rpm. 

What does ethos read at 2000? shut car off for 10 minutes and what does ethos read with engine off?


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## Cepromotion (Dec 10, 2012)

Video coming next.. im leaning toward leak and bad high pres sensor


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## snowwy66 (Nov 5, 2017)

That's what it sounds like. Leak and electrical issue. 

The compressor shouldn't be running though.


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## Cepromotion (Dec 10, 2012)

https://youtu.be/qXSu8vN55Vw

I cannot find fluorescence under UV on anything under the engine bay, except the outer portion of the caps. Im guessing from checking pressure and filling. Not much on the inside of them. The condenser looks fine, I may have to end up sending a vehicle to the shop for first time ever.

I am done for the night, I am pretty stumped and I am going to read into the system more tomorrow. I don't know much about the new style variable ac compressor, I have only worked with older ones. Is it possible for something to block pressure.. or is the High-Pressure switch lying to me. I cannot read the low-pressure switch from the ethos atleast not that I have seen yet. Might be time to trade this **** thing in.


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## snowwy66 (Nov 5, 2017)

I"m not sure if the low pressure sends a signal to read yet. I haven't seen anything so far. I just recently found out about the hi pressure readout. 

Freon contains pag oil. Pag oil contains the dye. So you should see green somewhere like a coolant leak. If you're finding it under the caps. The shrader valves are a very common leak. Luckily you can replace those without replacing the entire hose assembly. 

1 thing i would try is disconnecting the hi pressure readout and seeing if anything changes on ethos. AND, if your compressor still runs. That outta tell you if it's the switch or a short somewhere. I haven't looked at your video yet.

As far as i can tell about the variable displacement. It's all done through that controller valve. I posted the link on earlier. 

I"m just not seeing anyway to trap freon somewhere where the compressor would run. Hi pressure reads. Yet nothing comes out of charging ports.


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## snowwy66 (Nov 5, 2017)

GOOD JOB on the video. 

I see THREE things wrong in that video. Compressor isn't supposed to be running. Hi pressure not reading. AND. Evaporator temp reading 39 degrees with no freon. 

If your vacuum didn't leak. I'd say shrader valves would be your likely leak in the charge ports. 

If you noticed your evaporator temp. It said 39 degrees. That's not possible as you got no freon in the system. Combine that with your constant false hi pressure reading. And your compressor running. You've got TWO false sensor readings. And 1 electrical issue. 

Without a wiring diagram to be sure. I'm gonna say your problem is in the ECM/PCM or whatever it's called on these cars. Or your BCM. 

Don't run the compressor anymore. You're going to burn it up. You can tell what's going on by just having the key on. The clutch will engage. Just look at teh clutch instead of running the compressor bone dry. Not till you get freon in it anyways. 

I think what i do if i were you. Change teh shrader valves. Both hi and low. Vacuum and filler her up to 250 pounds on the high side GAUGE. That's 22.4 ounces if you go by cans. Not the ethos. And call it good. So you'll have freon in teh compressor. 

Change the negative battery cable like what keeps on getting recommended. If you haven't done that already. If the problem still persists. Start looking for the AC WIRING DIAGRAM. And looking for ecms or bcms from wrecking yards if that's what the wiring diagram points too. Obviously check the 2 sensors first before condeming the ecm/bcm.

I"m gonna go out on a limb though and say you've got 1 circuit causing 3 failures. Which COULD be the module. But hopefully it's a battery cable issue. Ecm/bcm not getting a good ground. 

Those 2 lights on the dash I"m guessing are trouble codes in the ecm.


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## Cepromotion (Dec 10, 2012)

Thanks for all your help snow. Gonna buy a sniffer and a few cans of r134a. I did unplug sensor and read 0psi on ethos.

Once i plugged it in, it spiked to 300 and setlled back to 87-97 again (engine off).

When i added r134a yesterday, i thouhht i hesrd a hissing sound near pump. What about the safety valve? I cant see it from front though.


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## snowwy66 (Nov 5, 2017)

I don't know anything about the safety valve. Other then what i read on it today. I haven't had to screw around much with these newer systems yet. I retired 20 years ago so i learn a lot of new things on this forum. I keep my hands wet with ac problems. But just the basic stuff. Nothing sophisticated. Specially on the newer cars. This forum is pretty much my only learning tool these days. And teaching where i can. Just like everyone else. 

If you charged yesterday and empty today. You've got a leak somewhere so anything is possible. From what i read about the safety valve. I don't think that's going to be your problem. Other then maybe a leak. But it's possible. You've definitely got electrical issues. 

At this point. I'd be trying to get my hands on some troubleshooting trees. It's what the dealer would be doing. Or SHOULD be doing. If they were to work on your car. 
I'd also be looking for the ac wiring diagram. Autozone has some guides but they apparently aren't carrying the cruze. Or possible not updating the system anymore for anything. 

I fixed a 96 cherokee couple weeks ago. Her particular electrical issue turned out to be the pcm grounding out the compressor relay. Basically causing a short and overloading the relay. Bought a haynes for the girl owner but it didn't have the ac diagram. Autozone did luckily. So you might look into chilton. One of them also has a monthly charge for websight. I'm thinking i might subscribe to see if it might be of any help to this forum.


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## snowwy66 (Nov 5, 2017)

Since you unplugged the high pressure and ethos dropped to zero. You could probably try a new switch. $30. And go from there on your electrical. Or pick one from a junk yard to try in case it's not the problem. 

Let's not forget the negative battery cable. Seems like a lot of people have problems on this forum that seem to get fixed with a new cable. AC is one of them along with those 2 lights on your dash.


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## Cepromotion (Dec 10, 2012)

I got some diagrams from AllData.. gonna go over them today and ask an electrician at work to look at it with the fault areas highlighted.

Sniffer and r134a ordered.


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## Taxman (Aug 10, 2017)

Could it be the compressor shaft seal, behind the clutch?


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## Cepromotion (Dec 10, 2012)

Not sure exactly where because I cannot see it. The vacuum held, but I plan on getting new valves for Hi-Lo and a sniffer and can of freon.

Is there a real schrader valve to upgrade hi side? I see a doorman part on amazon, but it says doesnt fit. The OE ball design sucks.


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## snowwy66 (Nov 5, 2017)

Amazon isn't the way to go.

Rockauto.com or autozone.


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## Cepromotion (Dec 10, 2012)

snowwy66 said:


> Amazon isn't the way to go.
> 
> Rockauto.com or autozone.


Yeah ordered from rockauto just wondering if there is a part # with an actual schrader valve for the high pressure port that swaps in.

Ordered stock for now, will report back later.

Btw those codes on dash were power steering service and frt windshield wiper relay issue.


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## snowwy66 (Nov 5, 2017)

Grandma wants to know if you got that thing fixed yet? LOL

If you can find it. Unplug the evap temp sensor and see what ethos reads. I"m betting it'll stop the compressor from running. 

rockauto lists it as a refrigerant temp sensor for $13. I"m thinking it's going to be what used to be called a low pressure switch. The only other sensor is the refrigerant pressure sensor for $27. I'm guessing that's what used to be called hi pressure or pressure fan switch. 

Your problems might be simple and just need those 2 switches replaced.


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## Cepromotion (Dec 10, 2012)

Sigh.. yeah she probably does wants to know.

Replacing the sensors shouldnt be an issue.. ill have to locate the evap temp sensor on my diagram.

I dont want to start throwing a bunch of parts at it though and end up with a headache more so than it is now. After looking at the schematic, it seems like all of these sensors are routed to the K30 control module; then to the fuse block underhood by the coolant reservoir. Im wondering if she may have spilled some coolant on it.

Anyway, where I am right now;
Diagnosing the circuits
Borrowed a vacuum pump to see if i can hold vacuum overnight
Ordered the schrader valve and ball valve for hi/lo service ports
Ordered a sniffer / freon with pag 46
Ordering a ground cable today

The hunt continues.


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## snowwy66 (Nov 5, 2017)

Cepromotion said:


> The AC High pressure sensor is changing while the car is off, power on. I did all the diagnostics and everything passed up until the "Diagnose/Replace B1 AC High Pres Sensor" So the circuit is good, it's either the sensor or the actual PSI on the system is wrong. Don't get why the pressure would be jumping around while the car is off though.
> 
> The P0533 S0 is Sensor Circuit High; yet the sensor is reading low and jumping


Looking at the diagram and see how it reacts. I think you answered your own question in this paragraph. 
Diagnostics all pass. Diagnose/replace sensor.


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