How to reset the a/c compressor?

The DTC's can be cleared in two methods, Scan Tool method or On-Board diagnostic method...

Clearing (DTC)s On-Board Diagnostic Method
1. Press OFF and WARMER (digital IPC) or OFF and PASSENGER WARMER (analog IPC).
2. Press LO (fan speed) button until Air Conditioning Programmer (ACM)? appears.
3. Press HI (fan speed) ACM CODES? appears.
4. Press LO (fan speed), ACM CLEAR CODES? appears.
5. Press HI (fan speed) to clear codes. ACM CODES CLEAR appears.

The compressor will reset after the system is full of refrigerant here is a guide to help you.

https://www.2carpros.com/articles/air-conditioner-how-to-add-freon

Please let us know if you need anything else to get the problem fixed.

Need to know - when you take a car your car in for a/c repairs - is it standard practice to leak test the system before doing any work?

I took my caddy in cause a/c had quit working. Compressor was noisy and had a burnt bearing smell. Clearly there was a problem with compressor and it was changed. Morning after I took car home I heard a soft hiss under the dash and then a soft "pop" and a cloud of freon(?) come up from the right side of the engine (hood was open to jump car). Took car back and was told I had an evaporator leak.

Called another mechanic who said system should've been leak tested before compressor work was done. Said he always does this as compressor went out for a reason and no sense replacing compressor if there's a bigger problem, etc.

I told my mechanic this and he said he couldn't leak test system with shot compressor. I think he could've - but I don't know.

Short/long - 2 quesitons:

(1) Is it standard practive to leak test a/c systems before doing repairs, and

(2) Can you leak test an a/c system with a shot compressor?

Generally when you charge a system, and especially when you replace a part.
You “suck it down”, meaning you attach a vacuum pump to the system. And let it sit there.
This does two things,
It helps to remove any moisture, as water will boil at lower temps when it’s in a vacuum, think of the reverse of a pressure cooker, where water doesn’t boil because it’s under pressure.
Second, if there is a big leak you will notice it, and if you leave the system in a state of vacuum with a gauge on it, you can even detect small leaks, if you leave the gauges on it long enough.

Saying that.
Putting the system in a vacuum is very mild pressure (about 32 inHg)
compared to what happens on the high side when the compressor is running (about 250 psi)

So it is completely possible that your car was just fine when it left the shop the first time.
And the failure happened later.
Even sitting with the engine off, a fully charged system has about 75 psi in it.

so...
[quote:01902c046f="mattbrady"]
(1) Is it standard practive to leak test a/c systems before doing repairs,[/quote:01902c046f]
No

[quote:01902c046f="mattbrady"]
(2) Can you leak test an a/c system with a shot compressor?[/quote:01902c046f]
kinda.
you do a vacuum test, (see above)
and a few, and i really mean a few specialty places have nitrogen leak testing equipment.

Thanks for feedback. Clarification please?

(1) My mechanic told me when I picked up the car that he'd put a green dye in the freon so he could see leaking with a black light - if I had a leak. He said he thought I might have a leak - since compressor went out and no freon in system when he went to do repairs. He told me to drive the car for a few days and then bring it back it so he could give it a once over for leaks.

(2) The morning after I brought it home I started it and that's when I heard the soft hiss under the dash and then hiss/pop/cloud of freon (?) on right side of engine. Cloud of vapor was not green - so not sure about the green dye claim he made.

(3) Having said all that - I have 4 questions:

(A) If you were given a car with a noisy compressor to fix - would you have evacuated the system/noted leaks and not gone any further until leak situation had been discussed?

(B) Since a/c was blowing cool (not cold) right before it quit and I smelled burned bearings - is it likely that freon leaked out slowly and a/c was able to still blow cool right up to the time the compressor crapped out?

(C) Hissing sound ("soft" sounding - but still noticeable) under the dash never occurred before. The morning after I brought car home was first time I heard. Could the mechanic, while repairing the compressor/charging the system, overcharge the system/pop a seal? Only reason I ask is I never heard the hiss before and his voicing a concern about a system leak/coming back to me telling me for sure evaporator has a leak after I took car back makes me wonder if he did something to cause hiss/leak to occur. Thoughts?

(4) Since Caddy's not worth much - would this be a good time to try CryoSeal?

[quote:ae826fb5f0="mattbrady"]Thanks for feedback. Clarification please?
(A) If you were given a car with a noisy compressor to fix - would you have evacuated the system/noted leaks and not gone any further until leak situation had been discussed?

(B) Since a/c was blowing cool (not cold) right before it quit and I smelled burned bearings - is it likely that freon leaked out slowly and a/c was able to still blow cool right up to the time the compressor crapped out?
[/quote:ae826fb5f0]

I'll address these two together.
With the system not being very cold, it could have had a slow leak, or the compressor could have been weak.
If you have a very slow leak (as you suggest you may have in B) It is hard to find without using dye.
When you put the dye in the system, the results are not instantaneous, the car has to be driven and the AC has to be used for the dye to circulate in the system. Sometimes for weeks.
So discussing the cost to repair any leak was not an option, because no leak had been proven.
PS, it is a very small amount of dye, you would not have noticed a green vapor.

[quote:ae826fb5f0="mattbrady"]
(C) Hissing sound ("soft" sounding - but still noticeable) under the dash never occurred before. The morning after I brought car home was first time I heard. Could the mechanic, while repairing the compressor/charging the system, overcharge the system/pop a seal? Only reason I ask is I never heard the hiss before and his voicing a concern about a system leak/coming back to me telling me for sure evaporator has a leak after I took car back makes me wonder if he did something to cause hiss/leak to occur. Thoughts?[/quote:ae826fb5f0]
More likely what happened, your system had a slow leak and was low on freon, or the compressor was weak. The system hasn't had to deal with normal operating pressures for a long time.

Once the system had the correct amount of charge, a weak component finally failed. It happens all the time with pressurized lines, a very weak part fails, you repair that and then the next weakest part fails.

[quote:ae826fb5f0="mattbrady"]
(4) Since Caddy's not worth much - would this be a good time to try CryoSeal?[/quote:ae826fb5f0]
You can try it if you want, but I don't have much faith in snake oil products.

Finally.
By what you have said so far, I feel that Your mechanic didn't do anything wrong and has followed standard operating procedures.
But ultimately, If you don't trust him, then go with your feelings and find a different one.[b:ae826fb5f0][color=red:ae826fb5f0] You both will be better off.[/color:ae826fb5f0][/b:ae826fb5f0]

(1) If you were given a car with a noisy compressor to work on - would you evacuate the lines/put system on a vacuum/note if vacuum held before proceeding to replace compressor?

(2) Since car is now hissing/popping/releasing a cloud of vapor on the driver side of the engine when it runs (compressor is on passenger side) - could it be that the orifice wasn't replaced/is clogged and/or something other than a leak in the evaporator is causing the hiss/pop/vapor under the hood?

Adding R-134. Compressor will not engage or cycle.

Are you useing gages to check pressures while you are installing the 134?

1. Could still be under charged and the pressure switch on compresser is not being activated.
2. Could be blown fuse, relay or circuit breaker caused by low system over loading circuits.
3. Is compressor actually locked up or clutch bad?
( Was it working before and you are just topping it off? )
4. Was system opened to air for any reason? ( Open system draws moisture and destroys the integrity of the system. Acccumulator should be changed and system vacumned down before addition of 134.

Best I can do with info I have.

[quote:8e9f183ddc="mattbrady"](1) If you were given a car with a noisy compressor to work on - would you evacuate the lines/put system on a vacuum/note if vacuum held before proceeding to replace compressor[/quote:8e9f183ddc]No.
If the system is holding enough pressure for the compressor to run, then it's going to hold enough vacuum to pass that test.
or
If a car comes in with a locked up compressor,
9 times out of 10 the seal on the compressor is damaged and would fail a vacuum test.

[quote:8e9f183ddc="mattbrady"]
(2) Since car is now hissing/popping/releasing a cloud of vapor on the driver side of the engine when it runs (compressor is on passenger side) - could it be that the orifice wasn't replaced/is clogged and/or something other than a leak in the evaporator is causing the hiss/pop/vapor under the hood?[/quote:8e9f183ddc]Is this hissing/popping/releasing a cloud of vapor thing on going?
It should only happen one time, after that the freon has leaked out and it cant do it again.

And could you clarify, in one post you said it was coming from the right side of the car, and now you said it is on the driver's side.

[quote:d0e3cdbc69="krisk2003"]Air Conditioning problem
1997 Cadillac Deville V8 Two Wheel Drive Automatic 80000 miles
----------------------------------------------------------------
Adding R-134. Compressor will not engage or cycle.[/quote:d0e3cdbc69]


did it stop working at some point? why are you adding freon. if codes are present for the ac system it wont work you have to reset them

off and warmer on the heater controls w/ key in the on position. the 3 buttons up by the IP is where you reset them, the buttons you use to get to the alt output, RPMs, cooling temp, etc. it will go to do you want to erase codes when in diag mode

(1) Compressor was making noise - i.e. It was turning but I think innards were shot. May not have been able to test for leaks in this condition?

(2) On the noise/vapor - Hiss/pop/vapor release happened when I started car up morning after I brought it home from mechanic. It happened twice. One hiss/pop/vapor release then a second hiss/softer pop/much smaller release of vapor.

Insofar as the hiss/pop/vapor on driver side when compressor's on passenger side issue goes - any ideas?

P.S. - My bad on using right side. I meant the issue's on the right side of the engine if you're standing in front of the car. Figured it would be better to start talking like a mechanic - i.e. use driver/passengerr side instead of left/right.

[quote:fb2e9bd4b6="mattbrady"](1) Compressor was making noise - i.e. It was turning but I think innards were shot. May not have been able to test for leaks in this condition?[/quote:fb2e9bd4b6]Sure, he could have tested for leaks, but it would have passed. And I'm going to bet that he knows that.

[quote:fb2e9bd4b6="mattbrady"](2) On the noise/vapor - Hiss/pop/vapor release happened when I started car up morning after I brought it home from mechanic. It happened twice. One hiss/pop/vapor release then a second hiss/softer pop/much smaller release of vapor.

Insofar as the hiss/pop/vapor on driver side when compressor's on passenger side issue goes - any ideas?[/quote:fb2e9bd4b6] Was this vapor close to the radiator or back near the fire wall? but right now I cant think of anything on the right side.

[quote:fb2e9bd4b6="mattbrady"]P.S. - My bad on using right side. I meant the issue's on the right side of the engine if you're standing in front of the car. Figured it would be better to start talking like a mechanic - i.e. use driver/passengerr side instead of left/right.[/quote:fb2e9bd4b6] We say left and right also, but it's as you are sitting in the car, not standing in front of it.

so the roadside, driver's side and left are all the same,
as is curbside, passenger's side and right.

now to really mess with your head...
the left side of your engine is pointing towards the front of your car, and the right side of the engine is facing the rear of your car. :)

Thanks for input so far. Need some clarification so gonna ask questions a little different/provide some add'l info along with so I can stop bothering you :)

(1) If someone brought you a car with a noisy compressor and, as you proceeded to evacuate the freon you found no freon in the system - would you assume the system had a leak and leak test the system before you did the compressor replacement as a matter of course?

(2) If after replacing the compressor you sent the car home and your customer came back next day telling you he'd heard a hiss/pop under the hood and saw a puff of vapor come up on the driver side of the engine halfway between the radiator and the firewall - would you suspect there was a problem with the compressor you'd just installed or what?

[quote:ff811c6cf2="mattbrady"](1) If someone brought you a car with a noisy compressor and, as you proceeded to evacuate the freon you found no freon in the system - would you assume the system had a leak and leak test the system before you did the compressor replacement as a matter of course[/quote:ff811c6cf2]
I've answered this question twice already. I'll try a different way of explaining myself as well.

These two facts in your question cannot exist at the same time
"a car with [b:ff811c6cf2]a noisy compressor[/b:ff811c6cf2] and, as you proceeded to evacuate the freon [b:ff811c6cf2]you found no freon in the system[/b:ff811c6cf2]"
There are sensors on the car that keep the compressor from coming on if it's out of freon.
So if the compressor is coming on, I know the system holds at least some pressure. And a vacuum test would not show any problems.
Now I'll offer you a alternate scenario.
Car comes in.
AC system is empty,
I circumvent the safety switch to see if the compressor will engage.
The compressor makes noise.
I replace the compressor.
Put dye in it.
Charge the system.
Since the compressor was bad, it most likely had a bad main seal as well.

If another leak is found, i would give the customer another estimate.
If no leak is immediately found, i would send it home. Comfortable with the knowledge that the dye will help pinpoint the leak if/when the customer comes back.


[quote:ff811c6cf2="mattbrady"]
(2) If after replacing the compressor you sent the car home and your customer came back next day telling you he'd heard a hiss/pop under the hood and saw a puff of vapor come up on the driver side of the engine halfway between the radiator and the firewall - would you suspect there was a problem with the compressor you'd just installed or what?[/quote:ff811c6cf2]I would try to duplicate the problem to determine the failed part.

overheat compressor off fan don'ts work

10-4. But the compressor wasn't running when I took car to shop. A/C had stopped running and I smelt a burned metal smell so I never re-engaged the a/c. I just took car to shop and, with just the engine running - there was noise coming from the compressor and the mechanic said I needed a new compressor.

All I'm asking is this:

Before he yanked the compressor - should he not have evacuated the system and in so doing discovered the leak in the evaporator (which is what he now says I have and what he now says caused the a/c system to lose freon and compressor to fail)?

what can i do to resolve compressor fans over heat problem

[quote:0a88028817="mattbrady"]Before he yanked the compressor - should he not have evacuated the system and in so doing discovered the leak in the evaporator[/quote:0a88028817]
I'm sure he evacuated the system, as it's the law. That is not doing a vacuum test.
Should he have performed a vacuum test???
I would not have.

And further more. From what you have told me, it is my opinion that the evaporator was still in working order when it left the shop.
You witnessed the very moment that it failed the next morning.

what do you mean compressor fans overheat the a/c fan for cooling the car? check fuses and relays under hood if it's the fan for hvac unit that will be under hood as well if fan doesn't come on then the control system has to be scanned to see what is wrong with it.

what's the name and city of the shop,
I want to check them out on the better business bureau website.

Not to stick my nose in this business, but I have been reading this and have some input. It sounds like the vehicle was brought in with a drive plate sheared, and compressor seized. There should have been some noise, smell, degraded performance leading up to this. It is not customary to assume there was a leak since the system was still trying to operate. To add to system dynamics, you can have a leak under pressure, and not under vacuum, or vice versa. Think of a connection or o-ring, as it is pulled down it is pulled together and may not lose vacuum, when under positive pressure it spreads and leaks. A leak test can cover both vacuum and pressure. Have you identified where this leak is?, the evaporator is on the passenger(right) side firewall where the large line, and small line enter a case. If you had a evaporator leak, it would more than likely expell into the passenger compartment. My guess, if it leaked after the repair, the shop kinked a line, left a connection loose, used wrong o-ring seals, or somehow the condenser got punctured. There is nothing on the right side, other than the high side line to the condenser. Two connections, one at the orifice tube, and one at the condenser. Was there metal in the system? The reason I ask, is sometimes shops opt to put a filter in the line. This filter is placed in that line in a location that is at the technicians discretion. The line is cut, and the filter is attached with compression fittings. If you had a pop/hiss/vapor, you should also have oil to show where the leak is. It sounds like the shop don't want to admit, or assumes, it did nothing wrong. That is my two cents, if I stepped on any toes, let me know.

[quote:f174bf347a="gstacey"]Not to stick my nose in this business, but I have been reading this and have some input. It sounds like the vehicle was brought in with a drive plate sheared, and compressor seized. There should have been some noise, smell, degraded performance leading up to this. It is not customary to assume there was a leak since the system was still trying to operate. To add to system dynamics, you can have a leak under pressure, and not under vacuum, or vice versa. Think of a connection or o-ring, as it is pulled down it is pulled together and may not lose vacuum, when under positive pressure it spreads and leaks. A leak test can cover both vacuum and pressure. Have you identified where this leak is?, the evaporator is on the passenger(right) side firewall where the large line, and small line enter a case. If you had a evaporator leak, it would more than likely expell into the passenger compartment. My guess, if it leaked after the repair, the shop kinked a line, left a connection loose, used wrong o-ring seals, or somehow the condenser got punctured. There is nothing on the right side, other than the high side line to the condenser. Two connections, one at the orifice tube, and one at the condenser. Was there metal in the system? The reason I ask, is sometimes shops opt to put a filter in the line. This filter is placed in that line in a location that is at the technicians discretion. The line is cut, and the filter is attached with compression fittings. If you had a pop/hiss/vapor, you should also have oil to show where the leak is. It sounds like the shop don't want to admit, or assumes, it did nothing wrong. That is my two cents, if I stepped on any toes, let me know.[/quote:f174bf347a]

gstacey - you seem to have a much better handle on what my situation is than buddycraig. You have any idea why hiss/pop/vapor would occur on driver side of engine shortly after starting up car morning after I brought it home? Seemed pretty strange to me - that and the fact that when I came home there was a large bolt on the drive where the car had been sitting - obviously a part the shop did not install but left loose and it fell out when I drove off!

what kind of level ride compressor is on a 1997 cadillac deville? i can't find anything on it and i took it to the shop and they told me that my compressor lines were damaged when they checked my level ride. please help.

[quote:495212a180="sheron1981"]Suspension problem
1997 Cadillac Deville V8 Two Wheel Drive Automatic 113712 miles
----------------------------------------------------------------
what kind of level ride compressor is on a 1997 cadillac deville? i can't find anything on it and i took it to the shop and they told me that my compressor lines were damaged when they checked my level ride. please help.[/quote:495212a180]

the compressor is in the right front of the car behind the bumper, scan your codes first, off and warmer on the heater controls at the same time, with your key in the on position


does your rear end stick all the way up in the air or whats your trouble a rough ride? scan your codes!!!

Without being able to physically inspect the vehicle myself, I would suspect that some part of the job was done incorrectly and/or poorly. Like I said in my most recent post, there is nothing but a high side line running on the left(drivers) side of the engine. Have you inspected it for a damaged line and/or signs of oil. If the refrigerant leaked, it carries the system oil with it, that was the vapor that was seen. If the shop just replaced the compressor, nothing should have been touched in that region. As I said also, did they install a filter in the line? This is often installed after catastrophic compressor failure, in attempt to prevent any rogue metal particles from reaching the replacement compressor, the line is cut and filter installed using compression fittings. It sounded to me all along, that the initial diagnosis and repairs were done accordingly, but that something went wrong. They told you it needed an evaporator, usually those don't pop, they slowly leak, and how did they come to that conclusion. There is a pressure relief valve on the back of the compressor, it lets off at pressures of approximately 525psi to prevent system damage. If the shop is saying that it is not their fault, and something else failed, have them show you where it is leaking. Otherwise, have a second opinion.

The a/c compressor cycles when i have the heater on. I t does not cycle when the desired temp is low. Does the high side thermistor have anything to do with cooling fan operation?

It should not cycle at all when ambient temp is below 40F. It will cycle when in defrost, and/or when in 'auto' and the temp is above 40. The high side temp sensor does have some affect on cooling fan operation. Higher than normal high side temp may indicate reduced airflow across the condenser, say when idling in traffic and the weather is warm. They would come on high in an effort to increase flow across the condenser.

[quote:6ce2362b76="bdc"]Air Conditioning problem
1997 Cadillac Deville V8 Front Wheel Drive Manual 93000 miles
----------------------------------------------------------------

scan for codes, push off and warmmer, at the same time, if it has codes it wont work, so hes not telling the truth if it has codes, because system wont power up

thank you where can i find the code numbers and answers.thanks brett

thank you very much i did what you said and this is what came up.
pcm 1139 current,
i pc b 1552history,
ipc u 1255 history
,acm b1310 history ,
acm b1347current,
tcs c1255 history,
pzm b1552 history,
pzm b 1558 history,
ipc b1771 history.
do you knowwhat this means .thank you very much .brett

[quote:4f7b08d849="bdc"]thank you very much i did what you said and this is what came up.
pcm 1139 current,
i pc b 1552history,
ipc u 1255 history
,acm b1310 history ,
acm b1347current,
tcs c1255 history,
pzm b1552 history,
pzm b 1558 history,
ipc b1771 history.
do you knowwhat this means .thank you very much .brett[/quote:4f7b08d849]

the current codes acm b1347 is an ac code low refridgerant you still have a leak, will have to get my caddy book out for the pcm 1139, will get back with you

I only drive this car about once per month. I put a new compressor in about 2 years ago. After the car sits several weeks and you turn the A/C on it makes a grinding grunting noise and then works fine. If I drive this car ever few days this does not occur, it is just if it sits up for a few weeks. Any sugestions would be appreciated.

It is possible that oil is settling in the compressor, and the noise your getting is described as slugging. The compressor is processing liquid, which don't compress. In theory, it could be detrimental to the component, have never seen a failed compressor because of it.

Thank you very much for your reply. I had one other person tell me this, but in all the years I have had cars that have set up for several weeks this has never happened before.

It is possible that when you had the compressor replaced, the oil that was added to it created too much in the system. Since you don't have any idea how much oil is in the system to begin with, and adding oil to a component is required at replacement, it is easy to have too much. If you were to have something done about it, a simple evac and recharge may resolve it.

I had that done yesterday. I hope that cures the problem. Thanks for your help and quick reply.

The evacuation and re charge did not cure the problem. Any more ideas. This is about to drive me crazy. I am so anal about my cars.

Not really sure at this point, without hearing the noise I can only guess that that is what is occurring. To remove and drain each component in order to get an idea how much oil is in there would be costly, Do you feel it is enough of a concern to warrant spending the money on?

No, not at this point. I drove the car to my mechanic this a.m. and did not turn the A/C on until i reached the garage. It made a little noise, but not like it has been doing. He thinks the noise is coming from the compressor and advises me to drive it on. I think what I will do is drive a few miles before turning on the A/C as he said it might give the oil time to heat up. Thanks for all of your help.

The dash control for AC will not go in "Auto" mode. When it is pushed it goes back to "economy" mode. Know for sure the 10 amp fuse is good and AC relay is good. There is no voltage at the compressor. How do you fix this?