2003 - transmission slams into drive. AC stops working when still and overheats - fan doesn't move. Now transmission problem.

I tried again and it's getting the same result. I scanned the codes and it found no logged fault code but it DID find a pending fault code. P0113. Intake Air Temperature Circuit High Input. The RPM started at about 1200 and then went down to over 500.

I was going to have a car maintenance day, but had plans so I couldn't... But tomorrow I think I'm going to run seafoam in the oil, go to Advance Auto pick up transmission fluid, filter, and gasket -- engine oil and filter -- and change the engine oil and transmission fluid, clean the MAF with my spray, and inspect everything else. I am still wanting answers if there is anything else I should look into and clean.

Not sure what kind of scanner tool you are using but u can prompt your fans through some check all fuses relays and connectors to cooling fans before you replace also sounds like you might be low on freon as far as the hard shift goes I'd check fluid levels at operating temps possibly a shift solenoid but can't say for certain and your iac could play a part in the rpms check the voltage it calls for running and not if that checks I'd clean the throttle body I suggest removing the tps and iac and giving those a good cleaning as well while you have the throttle body off .. As far as fan contributing to hard shift well that'd be a new one for me lol sorry but no such luck there

I mean, I know it won't be the fan causing the issue directly. I just thought there would be a specific part that plays it's own part in the fan, AC, and shifting. Also, I noticed whenever I turn the heat dial to circulate, AC lights up too and it appears that AC turns on because I can hear it. It has always been like this. This was my Gram's car (she passed in Nov. and I hit a deer days after) and she always said "Why do you always turn the AC ON?" I always said I don't, it comes on whenever we turn the dial to circulate. -- I checked the relay. Swapped it from heater/blower and the heater and blower still works but no fan movement. I'm not a Cavalier mechanic. I had when for a few months when I was 17, but then went to Mitsubishi. So I'm not familiar with this.

The only thing I changed was turning the heat selection mode to face so that the AC light doesn't turn on. Car started fine, shifted fine, etc. It shifts into second gear beautifully. I probably put it into 'drive' about 10 times without an issue. It always had a 'bang' when putting it into drive, but very subtle and not much of a notice. Anyhow -- I am still wanting ideas on what else to check.

Well nothing for the fans or ac is relevant to transmission issues the issues are separate and don't correspond with the problems each have ... My suggestion fix the ac/fan issue and then see how it acts shifting and go from there

Oh yeah I can tell you that this can be an IAT issue, I just fixed the same on my car. A rat chewed the IAT wires off, and it was showing NO PC current and a IAT temp of -40F. Set the P0113. Fixed the wires and reset the code and PC current went to .9 in park, .7 driving.

I can't edit, but before I fixed it AND cleared the code my transmission was also banging into gear. The lower your PC current is the higher the line pressure is in your transmission. Don't drive long like this or you will tear it up.

Two different problems. I have both on my 04 venture, exactly. They aren't related at all and the IAC has nothing to do with it the AC or the tranny banging. I haven't fixed my AC fan problem; it won't spin when the AC button is lit but it will spin when directly connected to 12v via a pair of + & - wires. Your tranny is just a POS like mine. Mine has been banging for 10 years, but only when I shift into D with a very cold engine/tranny. So when it's cold and I head-out, I start at 1st gear, then 2nd, then 3rd for about one or two miles, Then I can start out from D without it slipping and banging. I also add a bottle of Lucas Stop Slip for the transmission every couple of months. The tranny needs to be rebuilt and that will cost about $1500 to do it right, $900 for a cheap temp job - don't be cheap or you'll have to do it again very soon. :)

Please let me know if you find the solution to the AC fan - not turning on when the AC light is lit. :)