1999 C230 w202 AC issue
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Newbie
Joined: Jun 2014
Posts: 2
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From: Morristwn, NJ or Brooklyn, NY
C230
1999 C230 w202 AC issue
Hey. I've been cruising the forums for a while and got some good information but I haven't been able to find anything too conclusive to my problem. I apologize if this post is a little long.
I have a 1999 C230 and the AC seems to be blowing room temp air. Last year the AC was fine. This year it's been kinda fritzy. The issue itself is strange. When the temperature outside is only Warm (mid 70s) the AC blows cold air, but when it's hot out (80s-90s) it only blows room temp air. Last year it was fine.
So I downloaded the codes from the computer and 421 came up. Pulse Module. I have no idea what that was but a number of posts suggested cleaning the contacts. So after a few hours of internet searching and poking my car I was able to find it. (I still don't know what it does) and took it off and cleaned the contacts. They were already pretty clean, no corrosion or anything. I put it back on and cleared the error codes and checked again and 421 still came up.
I had an AC recharger. I attached the pressure gauge to the Low-pressure and got 170 PSI. Charged it up to the recommended PSI given the temperature outside. The air blowing was certainly cooler. But I noticed the gauge needle started to drop and stopped at 200psi. Hours later, it's still at 200psi.
I'm not too sure what the problem is. The compressor clutch turns. Right now the AC is working well enough after the recharge but I suspect that it will decline in a short amount of time. I don't know if it's a leak since the lines were holding a pressure before I recharged it.
Any suggestions? Thanks
I have a 1999 C230 and the AC seems to be blowing room temp air. Last year the AC was fine. This year it's been kinda fritzy. The issue itself is strange. When the temperature outside is only Warm (mid 70s) the AC blows cold air, but when it's hot out (80s-90s) it only blows room temp air. Last year it was fine.
So I downloaded the codes from the computer and 421 came up. Pulse Module. I have no idea what that was but a number of posts suggested cleaning the contacts. So after a few hours of internet searching and poking my car I was able to find it. (I still don't know what it does) and took it off and cleaned the contacts. They were already pretty clean, no corrosion or anything. I put it back on and cleared the error codes and checked again and 421 still came up.
I had an AC recharger. I attached the pressure gauge to the Low-pressure and got 170 PSI. Charged it up to the recommended PSI given the temperature outside. The air blowing was certainly cooler. But I noticed the gauge needle started to drop and stopped at 200psi. Hours later, it's still at 200psi.
I'm not too sure what the problem is. The compressor clutch turns. Right now the AC is working well enough after the recharge but I suspect that it will decline in a short amount of time. I don't know if it's a leak since the lines were holding a pressure before I recharged it.
Any suggestions? Thanks
Junior Member
Joined: Jul 2014
Posts: 15
Likes: 0
1998 C230
Hi Vishall,
I hope you have fixed your problem, however if not here's my input.
Just so we understand each other, your low pressure side is reading 200 psi? That is awfully high if so. To really know or diagnose the issue you would need a set of gauges for the low and high pressure sides. Your high pressure side should read around 200 and your low pressure side should read between 45 and 55, depending on the outside temperature. A new set of gauges should run you 100 bucks and come with a pressure/temperature chaft. If your high side is reading less than 150 I'd be concerned with compressor. A new compressor also requires a new dryer and txv valve, pag oil and o rings. Compressor, dryer, and valve should run you 291 bucks off Amazon. The rest can be purchased from your dealer or dealers website all for around 70 bucks. Then have an indie install it. In my case my indie wants 130 for the job.
I hope you have fixed your problem, however if not here's my input.
Just so we understand each other, your low pressure side is reading 200 psi? That is awfully high if so. To really know or diagnose the issue you would need a set of gauges for the low and high pressure sides. Your high pressure side should read around 200 and your low pressure side should read between 45 and 55, depending on the outside temperature. A new set of gauges should run you 100 bucks and come with a pressure/temperature chaft. If your high side is reading less than 150 I'd be concerned with compressor. A new compressor also requires a new dryer and txv valve, pag oil and o rings. Compressor, dryer, and valve should run you 291 bucks off Amazon. The rest can be purchased from your dealer or dealers website all for around 70 bucks. Then have an indie install it. In my case my indie wants 130 for the job.
