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1993 Deville
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Discussion Starter #1
I have two problems one I can't get the codes to come up the other is service A/C came on and blowing warm air. When I push the off and warmer on the electronic climate controller and hold them it will flash lighting every thing in the display then gives me three dash lines (---) and in the upper dash the service lights lite but shows 0 in the mph screen. I put a set of gauges on the low side of the A/C and have 100 psi and when I bought this car they switched it to 134 coolant when I push auto on the climate control is goes to econo and the service A/C comes on for a min then goes back off still blowing warm air
 

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1992 DeVille
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red-oak said:
I have two problems one I can't get the codes to come up the other is service A/C came on and blowing warm air. When I push the off and warmer on the electronic climate controller and hold them it will flash lighting every thing in the display then gives me three dash lines (---) and in the upper dash the service lights lite but shows 0 in the mph screen. I put a set of gauges on the low side of the A/C and have 100 psi and when I bought this car they switched it to 134 coolant when I push auto on the climate control is goes to econo and the service A/C comes on for a min then goes back off still blowing warm air

Codes will read out on the fuel data center screen which is behind the left hand side of the steering wheel. The electronic climate control is used to monitor the car while running. Various lights correspond to various parameters. For example the Econ light if illuminated means the car is running rich, if it's off it means it's running lean. All lights in the ECC have a meaning.

After you press off and warmer look at the fuel data center and get ready to write down the codes if any.

As far as the Ac, you'll probably throw an F47 for low refrigerant. That is why the Ac switches from auto to Econ. It is by design to shut the compressor off so it doesn't burn out when low on refrigerant. (Thank you Cadillac engineers)

Check those codes again and look at the FDC and let us know.


If your low on freon chances are you have a leak and need to fix it. I had similar Ac symptoms and rolled the dice to recharge with R12 and hope it won't leak. So far so good.



R134A molecules are physically smaller than the R12 and will have more of an ability to leak from your existing system
 

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1993 Deville
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Discussion Starter #3
Re: 1993 deville

Thanks I got the codes up and they are as .7.0 F31 F46 F47 then F.F. I think what makes it diffacualt to get the codes off is the fuel display works interment I replaced the battery last week and the fuel display seams to work much better not sure that would have much to do with it

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I can not get the A/C to accept any charge as I think the pressure on the low side is to high at 100psi
 

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1985 Sedan DeVille
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Re: 1993 deville

F31 - Display Panels to BCM Data Problem
F46 - Low Refrigerant Charge
F47 - Low Refrigerant Charge

You have to clear the F46 and F47 codes before it will allow the compressor to run. Then restart the car and set AC to AUTO, and run the charging procedure as normal. If it switches to ECON and throws the SERVICE light again, you gotta repeat
 

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1993 Deville
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Discussion Starter #5
Re: 1993 deville

Thanks I will try that I am trying to charge it with the cheep cans from auto parts store on the low side . Can I un hook the battery to clear the codes to get the compressor to run ??
 

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Re: 1993 deville

After you enter diag mode and the codes are displayed, and it shows 7.0

hold OFF and HI to clear ECM codes (E.*)

hold OFF and LO to clear BCM codes (F.*)

AUTO will leave diagnostics mode

Then turn the AC OFF and turn the car off, so you have enough time to get setup before you start up again
 

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1993 Deville
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Discussion Starter #10
I could not get the FDC to luminate this morning so took it for a quick run unhooked the battery with coolant attached to two low side restarted the car and A/C compressor ran and sucked in the coolant vents blow cool. After un-hooking the battery the FDC lite up off for a test run then wait to see if coolant stays in for a while I did not see any obvious leaks I only put in about 16o/z of a 19 o/z can of 134
 

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1993 Deville
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Discussion Starter #11
I took it for a run and it went back on econo and blew warm I put more coolant in it and now when the compressor clutch engages the gauge attached to the low side goes to 30psi and when it is not engaged it climbs up to 75 psi the low line is hot to the touch 171F and the hi line is cold but with out frost on it 77f an I still low on coolant?? still warm air in the vents had the clove box out and watched the activator moving the door on the heater box
 

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White Diamond '03 DHS (with DTS floor shift)
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the low side goes to 30psi and when it is not engaged it climbs up to 75 psi
That sounds about right, but what about the high side?

the low line is hot to the touch 171F and the hi line is cold
Where are you getting these temps? Check the pipes that go into and out of the firewall. They should both be cold and about the same temperature.
 

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1993 Deville
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Discussion Starter #15
I took the reading on the right side beside the recovery tank on the fender I am on my way to look at it again now. I am also going to look for a set of manifold gauges see if I can buy a set close by
 

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1993 Deville
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Discussion Starter #16
Yester day I did not get a chance to get anything done on the car. I did get thinking I have not owned it from new and have no idea what has been put in to the system it all started off from a working system then gave a low pressure fault on the low side and putting in a can charge of 134 did not solve the issue. but what I have noticed at 80F I have a static pressure of aprox 110 psi then starting the car at the orifice expansion for a few short mins it will frost the pipe and the gauge on the low side will go to zero when the compressor runs, then the
frost will go away and compressor will go on and off the pressure will go from a static pressure of 110 when the compressor is off and back to zero when it runs. I am wondering if there is a blockage in the system I and still looking for a set of proper gauges and a vacuum pump. thanks for all in puts on my issue
 

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White Diamond '03 DHS (with DTS floor shift)
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You have bigger problems than a leak.
Static pressure should be around 70 psi.
110 is way too high.
low side pressure at 110 is also waaay too high and dropping to zero is completely off the chart.
If you suspect a blockage, check the orifice tube. The fine screen acts as a filter and can clog up, but any debris in it indicates a failing compressor aka "Black Death".
http://autoacrepairs.com/gpage11.html
 

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1993 Deville
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Discussion Starter #18
The line on the high side is hot to the orifice or where I think the filter is or expansion tube then it is cold to the fire wall were I figure it goes in to the evaporator and warm at the receiver dryer and warm back to the compressor . Could the receiver dryer be plugged as I hope it is not the evaporator that is plugged. I agree the filter should be replace if the system is opened up.
 

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White Diamond '03 DHS (with DTS floor shift)
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The line on the high side is hot to the orifice or where I think the filter is or expansion tube then it is cold to the fire wall were I figure it goes in to the evaporator
Normal

What temps are the inlet and outlet pipes at the firewall? They should both be the same (cold) temperature.
 

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1993 Deville
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Discussion Starter #20
to the touch going in is cold and coming out is warm to hot. I have a friend coming over with gauges a pump and a recovery system over the weekend he has A/C experience. My thought is to evacuate the system put in the proper amount of coolant (134) to according to the service manual. because I have no idea what any one has done before me other than change the system over from r12 to 134 when I bought it two years a go and figured it almost normal for it to be a bit low after that time. So I have no idea if they just dumped the 12 tosses in 134 or even dew the system down heck they might of just changed the fittings and nothing more to get it out the door which would be a shame. the car is a documented California car with less than 30 thousand miles on it and not a mark any where so it is worth fixing at almost any reasonable cost to me
 
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