If the engine temp isnt displaying properly (seems to be always on the cold side), would that cause the A\C to not to be as cold becuase it thinks its colder than it is??

 

As far as I know, there is no connection between coolant temp and the A/C. You're probably either getting low on refrigerant or your blend door is is starting to break. Last summer, my A/C on my 96 X wasn't quite as cold as it should be, then the blend door broke completely, so I fixed it. Much colder now.

 

Also, if your temp gauge is always reading cold, you might want to check your thermostat as it may be stuck open.

 

okay two things
first your engine temperature DOES effect the A/C. If it is out of "normal" range as determined by the engine computer, the computer opens the WideOpenThrottle relay shutting off the A/C.

secondly you must remember that your gauge uses a different sensor than the computer.

how to repair:

FIRST it is imperative that you make sure you do not have a coolant leak. The location of these sensors is on the top of the engine. If the coolant is low, they will not read it properly and the computer goes goofy.

If your coolant is low, correct the leak, fill the system up and see if that corrects the problem.

As you have indicated a continuously cooler running engine, I suspect that you have the same problem as mine. The computer sensor went out of range causing the computer to think the engine was overheating.

Don't panic. It is an easy fix. Pick up a new sensor ($15 at Autozone). WITH A COLD ENGINE. Locate the old one under the hood (it will be near the thermostat and has TWO wires going to it. Get the new sensor ready by putting teflon tape on the threads. Remove the wiring from the old sensor. Remove the old sensor and quickly screw in the new sensor. If you are quick you only loose a couple of ounces of coolant. plug the wires back on and enjoy.

Good luck

 

okay two things
first your engine temperature DOES effect the A/C. If it is out of "normal" range as determined by the engine computer, the computer opens the WideOpenThrottle relay shutting off the A/C.

secondly you must remember that your gauge uses a different sensor than the computer.

how to repair:

FIRST it is imperative that you make sure you do not have a coolant leak. The location of these sensors is on the top of the engine. If the coolant is low, they will not read it properly and the computer goes goofy.

If your coolant is low, correct the leak, fill the system up and see if that corrects the problem.

As you have indicated a continuously cooler running engine, I suspect that you have the same problem as mine. The computer sensor went out of range causing the computer to think the engine was overheating.

Don't panic. It is an easy fix. Pick up a new sensor ($15 at Autozone). WITH A COLD ENGINE. Locate the old one under the hood (it will be near the thermostat and has TWO wires going to it. Get the new sensor ready by putting teflon tape on the threads. Remove the wiring from the old sensor. Remove the old sensor and quickly screw in the new sensor. If you are quick you only loose a couple of ounces of coolant. plug the wires back on and enjoy.

Good luck

 

Hi Robjonrik,

Since you like to be quoted, I'm going to quote you again!!

First, the PCM only senses a coolant temp TOO HIGH, not TOO
LOW.

Second, he is complaining about his temp gauge reading too low,
why would he replace the ECT sensor for the PCM? If the temp
gauge is reading too low, then if the problem is a sensor, it will
be the gauge sensor (with a single wire connector), not the
ECT sensor.

 

While you are correct in your observation, you have neglected to factor in what the ecm does if it "thinks" it is running too hot. It adjusts timing and fuel mixtures to compensate causing the engine to run cooler than normal on the guage...

This is 100% tried and true- been there done that technology. It drove me over the edge until I figured it out.

You can quote me on that.

PS if you check, i'll bet a quarter he has a lot of pinging at highway speeds from the computer over advancing

 

I thankyou both for your replys, unfortunately robjonrik you would be losing your quarter on that bet. The engine runs like a charm. The problem I am experiencing is that, the high side port of the A\C is in the correct range, the low side on the other hand has very high pressure with the correct amount of coolant in the system. The A\C only seems to be cold while driving, idle produces Nothing. The engine temperature gauge, is almost always on the cold side, never reaches "normal" unless driving through 3 states to rhode island. My original question was if this would affect how cold the A\C decides to blow, but i'm not very sure its affecting mine. I think something on the low side of the a\c may not be working as well as it should.

 

That's different. If you have a hight backpressure with a normal headpressure, you should suspect the expansion device. The purpose of this device is to create a restriction which in turn creates the pressure difference.

 

You don't mention what year your vehicle is, but I'm assuming it
is a newer model. If so, you don't have an expansion valve, you
have a capillary tube (orifice). I suspect that your compressor
has a bad valve in it. To verify this, try closing off (pinching) the line going to the evaporator. If the low side doesn't go into a
vacuum, then this will confirm it's the compressor.