Check Engine for What?

cavalier
engines
lights
chevrolet

#1

My “Check Engine” light came on steadily a month or so ago (right around the time my daughter told me the air conditioning started seeming intermittent). I had Auto Zone plug in for a free diagnosis and the cooling system was targeted as the possible culprit (mentioned a relay). So I replaced the two obvious cooler-related relays, but not the multi-purpose one, since I had no clue as to which purpose it was serving. My daughter was right - the car always blows air, but cool air only comes out when I am moving - increasingly warm air is emitted the longer the car is idling. HELP!!!


#2

What was the exact code Autozone read? It is in the format of Pxxxx. There are hundreds of codes, and each one has a specific definition.


#3

Does the electric cooling fan come on with the A/C?? It should. Anytime the A/C is on, that radiator fan should be running…


#4

I wiil ctitique a mechanic who cannot diagnois a car that shows symptons but no codes IF that mechanic has that car in front of him, but no critique at all when trying to do an internet diagnosis without the codes, we need those codes by the number to help out.


#5

I think that you are confused. The cooling system cools the engine. It probably runs between 200 & 240 degrees or so and will be used to produce the heat inside of the car.

The air conditioning system is completely different, and is used to produce cool air rather than warm air - yes, a little confusing I suppose that the “cooling” system produces the heat.

The thing that they share, as Caddyman noted is the cooling fan. It comes on to move air across the radiator and the condenser. The radiator goes with the engine’s cooling system. The condenser goes with the air conditioning and is likely mounted right in front of the radiator. The fan should come on a) whenever the AC is on to move air across the condenser, and b) whenever the engine’s coolant reaches X number of degrees (usually in the 230-240 range) to move air across the radiator. If your fan isn’t coming on with the AC then air will only move across the condenser when the car is moving.

Anyway, my first guess would just be that the AC system has developed a leak and is now low on refrigerant. You should just find a local shop that specializes in AC systems and ask them to check it out.

The check engine light was probably completely unrelated to the AC system performance. Should it come back on, have it scanned again and write down the exact code and post it (e.g. P1234)


#6

P0480


#7

Yes - the fan is running.


#8

P0480 - but I did not let the mechanic look at it yet, as he wants $90 just to tell me what’s wrong (based on the code I was going to give to him from Auto Zone).


#9

The code is P0480.


#10

http://www.bba-reman.com/content.aspx?content=DTC_P0480_WITH_AC


#11

I have a book with over 4,000 code descriptions. It is called “the most extensive collection of code descriptions ever” but no PO480.


#12

Have a look at the link that Caddyman posted below for how you get to the bottom of this problem. If you’re up to it then have at it. If not it might start to make $90 look reasonable.

You could try to just replace the relay and see what happens. Of course, the relay could be bad b/c it was blown by some other problem in the system so that could turn out to be a waste.


#13

I have it in my list.
P0480 - Cooling Fan 1 Control Circuit Malfunction

The $90 is a perfectly legitimate diagnostic charge. He needs to figure out exactly what the malfunction is. You’re paying for his time and expertise. In my area the minimum diagnostic charge typically runs over $100.

My honest opinion is that of you’re not willing to pay him for his time and expertise, you should buy a Haynes Repair Manual at the local parts store and try to do it yourself. You’ll learn that $90 is pretty reasonable.


#14

Book was about 60.00 and it misses codes like this occasionaly.


#15

I’m not sure any complete book exists. Obsolescence is a pernacious beast.