A/C Codes

[Noosh]

It actually hit 90 degrees here today, so...guess I'm going to work on the A/C sooner rather than later.  The PO stated that the A/C had just been filled with refrigerant less than a month ago.  The '89 has the following codes coming up

 

B448 history,  B447current.

 

The code comes up whenever I use the A/C, AND if I set the climate control to auto.  No matter if I'm heating or cooling a few degrees.  I haven't had need of the defrost setting yet...just thought of that.  I'll go give it a try in a minute, and add the results.

Additionally, I put an R134 can on it today (no, I did not add anything, I'm sure it calls for something different) and the gauge reads full.  Now, this is just an "off the shelf" can of refer from the auto parts store, so I don't know how accurate it is.  I will go try the defroster and see what happens.  I cleared the codes before sitting down to inquire.

Noosh.

---

OK, so turning on the defroster does NOT bring up codes, but as soon as I hit auto on the climate control ...boom..."447 Very low refrigerant, compressor shut off to avoid damage" code comes up. Any ideas?

[Frogware]

So what are the symptoms again just to be clear? Is the compressor cycling on and off or is it not working at all?

Thanks

-Scott

[Noosh]

So what are the symptoms again just to be clear? Is the compressor cycling on and off or is it not working at all?

Thanks

-Scott

 

Whether it is trying to start up at all or not, I couldn't say.  By the time I press the button to turn it on and get out of the car, it is not working, and an error code comes up.  It was 448, now it is 447.  The difference being low, and very low, respectively.   I would say not at all, because I'm not hearing the cursory "click" when the compressor would normally cycle on.  Tell you what though Scott, in the AM, I'll cycle the system again, and pay better attention to the time frame.  I believe, when I got it a week ago, it cycled on for a bit, before shutting down, and now it just won't allow it.  Thanks, Noosh.

[harry yarnell]

I thought you had to clear the codes before the BCM allows the compressor to kick in...or am I wrong?

[Ronnie]

Additionally, I put an R134 can on it today (no, I did not add anything, I'm sure it calls for something different) and the gauge reads full.  Now, this is just an "off the shelf" can of refer from the auto parts store, so I don't know how accurate it is.  I will go try the defroster and see what happens.  I cleared the codes before sitting down to inquire.

Noosh.

---

OK, so turning on the defroster does NOT bring up codes, but as soon as I hit auto on the climate control ...boom..."447 Very low refrigerant, compressor shut off to avoid damage" code comes up.  Any ideas?

 

If you were able to attach a R134 can to the system it must have been changed over from R12 to R134. When a system is changed over it will have an adapter screwed onto the R12 fitting like the one shown in the photo below if it has been changed. Otherwise it will have a smaller threaded fitting for R12. A system flush should have been done during the changeover or there will be problems down the road.

 

I suspect the Freon is low and the compressor is kicking out before enough Freon is added to the system - even though your gauge is reading full. The compressor must be running before Freon can be added properly.

 

The reason the gauge is reading full is probably because the compressor isn't running. When the compressor kicks on it will pull the pressure down. If there isn't enough Freon in the system with the compressor running it will pull the pressure down so low the BCM will kick out the compressor and throw the code you are getting.

 

The following tutorial will tell you how to add Freon when the compressor keeps kicking out and throwing a code.

Compressor Kicks Out When Adding Freon - Solution

[Ronnie]

I thought you had to clear the codes before the BCM allows the compressor to kick in...or am I wrong?

 

You posted while I was still typing.

 

You are correct Harry. The AC codes can usually be cleared in diagnostics but sometimes that won't work and you have do disconnect the battery cable to clear the codes. There must be something a little different about AC codes that causes that to happen

[Noosh]

God, how I love this forum!!! Ok, unplugged battery, opened doors, attached refrigerant can. Restarted on auto setting, and the compressor kicked in. Gauge on can dropped, and I started filling. Took the whole can, and the system works now. I'm still getting a code while it's running, but it's 446, "low, may effect performance. Biggest thing, is it's working. I'll go get another can, as when it cycles, the gauge still drops too low, and the code is up. Should be able to complete the fill, and be just fine. I will let you know when it's complete, but I have high hopes. I just can't express enough, how helpful you all are. A little time spent investigating, and all your input, makes (what I'm sure would cause me to light a complex auto on fire and watch it burn) maintenance and repairs SO much easier! If any of you are in Oregon, I'll buy you a cold one any day.

Noosh.

[Ronnie]

Good to hear you got it working.

[Frogware]

That is Great, Glad you got it working! We are happy to help, that is what this forum is all about.