Air Conditioning Not Working
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Joined: Dec 2007
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From: Miramar FL
Air Conditioning Not Working
When I turn on my air conditioner, the AC light comes on briefly and then turns off, blowers and everything else working fine. I have an 01 coupe A4 with the dual climate control system.
I had the same thing happen a couple of months ago and read a thread about disconnecting the battery briefly to reset the system, which worked at that time. During that time, I also had a mechanic friend check the refrigerant and he told me it was good.
I went ahead and checked the codes on the DIC. This is what I have.
10-PCM P0530 HC AC refridgerant pressure sensor circuit
28-TCS C1214 HC SOL valve relay contact ckt open
58-SDM B0026 HC LF driver frontal deployment loop open
I have no other codes, no HVAC codes.
I checked the pressure sensor plug, it's clean and appears to be fine. No damaged wires. I went ahead and ordered a new pressure sensor, but had a question on replacing it.
Do I have to evacuate the system before removing the old one? or do I just pull the old one and replace it without having to do anything else.?
I had the same thing happen a couple of months ago and read a thread about disconnecting the battery briefly to reset the system, which worked at that time. During that time, I also had a mechanic friend check the refrigerant and he told me it was good.
I went ahead and checked the codes on the DIC. This is what I have.
10-PCM P0530 HC AC refridgerant pressure sensor circuit
28-TCS C1214 HC SOL valve relay contact ckt open
58-SDM B0026 HC LF driver frontal deployment loop open
I have no other codes, no HVAC codes.
I checked the pressure sensor plug, it's clean and appears to be fine. No damaged wires. I went ahead and ordered a new pressure sensor, but had a question on replacing it.
Do I have to evacuate the system before removing the old one? or do I just pull the old one and replace it without having to do anything else.?
Last edited by Only in Black; Dec 27, 2011 at 11:35 AM.
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From: Van Buren Arkansas
Wounded Warrior Escort '11
There are two pressure sensors on it, not just one. One is for low and the other high. Was the car in a accident? That SDM code is something of a concern and possibly related to the AC, if it was in an accident....not if it was not in an accident. Most people should never mess with the airbag system and I would suggest the dealer right away for that. Back to your AC, a professional shop or the dealer should and can do the AC checkout for you and they will have the equipment to extract the refrigerant, evacuate and insert the correct amount. Its not like the days of old with the R12 systems. R134 needs specific amounts of refrigerant based on local temperatures.
Race Director
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From: Arizona
Related or maybe not, but my AC was recently blowing fine, but just blowing air. Not even cold at that. Took to local Brake Masters and was in and out in 30 minutes or so. Evac, Fill, Dye, 42 degrees cold!!! $137.00, this included 5 pounds ( or however the refrigerant is measured) of new refrigerant.
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Joined: Dec 2007
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From: Miramar FL
I'm a little confused. There are two pressure sensors? I only see one in the IPC. I see two service ports: one on the low and one on the high side. Where exactly is the second pressure sensor?
I think I was not clear in my original post. The freon level was checked and does not need any servicing.
The question I was originally asking is:
Can I replace the pressure sensor without having to evacuate the system?
I figure that the code I'm recieving is coming from the faulty sensor which would keep the compressor from kicking in.
Thanks guys for all your input.
I think I was not clear in my original post. The freon level was checked and does not need any servicing.
The question I was originally asking is:
Can I replace the pressure sensor without having to evacuate the system?
I figure that the code I'm recieving is coming from the faulty sensor which would keep the compressor from kicking in.
Thanks guys for all your input.
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Joined: Dec 2007
Posts: 80
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From: Miramar FL
AC light does not flash, which you are right, would indicate a low freon level. Freon level has been checked and is fine. I'm hoping it's just a faulty pressure sensor. Once a get the new one and install it, I will let you guys know if it fixed the problem.
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Tech Contributor
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From: Dyer, IN
Did you take a shot at the service manual procedure for a P0530 code? Also, don't bother looking for the other pressure sensor....because there is only one.....
Tech Contributor
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From: Van Buren Arkansas
Wounded Warrior Escort '11
Lucky is smarter than I by a long shot...I could have sworn that I read several times there are trips for both high and low pressure unless a single switch has both capabilities?
Tech Contributor
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From: Dyer, IN
The single sensor monitors pressure. It is truly a "sensor", and not a "switch"....which is why it has three wires going to it, instead of two. Like you, I was accustomed to A/C systems that had two pressure switches for the refrigerant system...one on the high side, and one on the low side(typically mounted on the accumulator itself).
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From: Miramar FL
I have not looked up the code in the manual, but will this weekend. Thanks for clearing up the sensor issue. I'm really hoping that is all that is wrong with the system and not something more expensive.
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From: Dyer, IN
2nd Gear
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One sensor
I'm a little confused. There are two pressure sensors? I only see one in the IPC. I see two service ports: one on the low and one on the high side. Where exactly is the second pressure sensor?
I think I was not clear in my original post. The freon level was checked and does not need any servicing.
The question I was originally asking is:
Can I replace the pressure sensor without having to evacuate the system?
I figure that the code I'm recieving is coming from the faulty sensor which would keep the compressor from kicking in.
Thanks guys for all your input.
I think I was not clear in my original post. The freon level was checked and does not need any servicing.
The question I was originally asking is:
Can I replace the pressure sensor without having to evacuate the system?
I figure that the code I'm recieving is coming from the faulty sensor which would keep the compressor from kicking in.
Thanks guys for all your input.
Tech Contributor
Joined: Jan 2007
Posts: 19,456
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From: Dyer, IN
There is only one sensor in my 2003 C5 Corvette. I went through this as well because I was going to try to jump the low pressure sensor, but I have one and it is referred to as a pressure cycling sensor. Mine does not have a low port because everything is through that one. It has three wires and is located just under your expansion tank with a wire running to the side of the compressor. You do have a high and low service port, but just the one sensor mine was $72 to replace.
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From: Cape Coral, Florida
There is only one sensor in my 2003 C5 Corvette. I went through this as well because I was going to try to jump the low pressure sensor, but I have one and it is referred to as a pressure cycling sensor. Mine does not have a low port because everything is through that one. It has three wires and is located just under your expansion tank with a wire running to the side of the compressor. You do have a high and low service port, but just the one sensor mine was $72 to replace.
You do NOT jump the sensor and if you do you can possibly fry your PCM jumping the 5 volt reference to ground !!…it is not a “switch”….it is a 3 wire sensor and reads the high side of the AC system…5 volt reference, a signal and a low reference.
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
The "10-PCM P0530 HC AC refrigerant pressure sensor circuit" tells you that you are having a problem with that sensor or the circuit for that sensor . As C5 DIAG stated , you can NOT jump that sensor without the risk of doing electrical damage.
First things first; Check the wiring at the connector to the sensor and then disconnect the sensor connector and look for corrosion, poor connection broken stuff. You can check the connector for the 5vdc reff voltage and check sensor low reff ground. However, the SIGNAL WIRE doesn't have any reference as to what the voltage should be at any given pressure.
If you have 5vdc Reff, & a good Circuit ground and you have checked the sensor signal wire for proper continuity connection to the PCM, the sensor is most likely bad.
From what I remember, the sensor screws onto a Schreader type valve and can be unscrewed without losing pressure HOWEVER,,, I strongly recommend that you prove out that theory prior to testing that theory. It SUCKS to have a gross refringent leak!! I will try to verify if you can safely remove that sensor without discharging the system.
First things first; Check the wiring at the connector to the sensor and then disconnect the sensor connector and look for corrosion, poor connection broken stuff. You can check the connector for the 5vdc reff voltage and check sensor low reff ground. However, the SIGNAL WIRE doesn't have any reference as to what the voltage should be at any given pressure.
If you have 5vdc Reff, & a good Circuit ground and you have checked the sensor signal wire for proper continuity connection to the PCM, the sensor is most likely bad.
From what I remember, the sensor screws onto a Schreader type valve and can be unscrewed without losing pressure HOWEVER,,, I strongly recommend that you prove out that theory prior to testing that theory. It SUCKS to have a gross refringent leak!! I will try to verify if you can safely remove that sensor without discharging the system.
