I have a 2001 SE with Auto Climate Control. I just bought the car a couple months ago, and I have had this problem since day 1. On "Auto" mode, regardless of the temperature I set it at, it will always blow ice cold air, with the only exception being when I turn it to 90. When I turn it to 90, it will blow warm air, but even at 89, it will still be ice cold.

I am sure there is a sensor bad somewhere, so I was hoping someone could help me out.

Thanks,
Dustin

 

Bump, anyone?

 

Ok I had this problem when I was messing with the stereo and unhooked the temp unit.... here is the fix.

Unplug battery for 10 minutes and it should go back to normal.

It worked for me and I am sure it will work for you.

 

Mine is the same way - freezing at any setting other than 90 degrees. (I've had the battery unplugged on several occasions and nothing seems to have changed with the temp setting.)

I've also been highly unsatisfied with the climate system as a whole since I bought the car. I didn't even look in the back when I bought it, but later noticed it didn't even have rear air vents. Wouldn't hurt to have dual-zone control either. Afterall, it is a "luxury" car.

 

if the interior temperature is higher than what you set on the A/C it'll blow cold air, otherwise, it'll blow hot air.
and another thing, maybe it's the dash gets too hot that the sensor is not reading the actual air temperature.

 

I guess that's a possibility. My car is black/black, so that would explain why the system would always want to blow out cold air. But on the other hand, black/black in Georgia after sitting in the sun all day makes the car a fiery hell to get into after work, so putting it at 90 degrees right when you get in the car would mean the car should be putting out cold air to cool the car down to 90 degrees.

Thank god I work at night and my car doesn't heat up while I'm at work just before I have to get in it to drive home

 

I understand what you are saying there, but this happens at any time, at any temperature outside. I drove from Omaha to KC and it stayed ice cold all the way down, regardless of what I set it to. It wasn't a particularly hot day out, and you would think that in 3 hours that the AC was one, the interior temperature would drop below 89.

There has to be an interior sensor that reads temperature.

 

It sounds like one of the sensors that system uses might be bad. In the FSM there is a section that explains how to put the auto climate control system into self-diagnostic mode. Maybe that would steer you in the right direction.

 

actually the way it works is that it will control temperatures from 61-89. if you turn it to 60, it will blow cold freezing air no matter what, and if you turn it to 90, it'll blow hot burning air no matter what the temperature is. At least thats what it says in the manual lol.

 

There are vents in the rear, under the front seats, they just don't work very efficiently.

Ron

 

After more research, I found this thead:
http://forums.maxima.org/5th-generat...-headache.html

There is a great write up of the diagnostics of the climate control system and how to test the sensors. In my case, I performed the "51" test and it shows the temp of the air exiting the evaporator at 131 degrees. Obviously, it thinks the air exiting the evap is superhot so it continually keeps the AC on, trying to cool that air down.

Anyone know where that sensor is?

 

Try the FSM. If I'm reading it correctly it appears your intake sensor is bad.
http://www.nicoclub.com/FSM/maxima/2001/HA.pdf

 

OK, so I ran the test in the "2001 Climate Control Headache!" thread and it came back with 131 degrees from the "Intake Sensor" or the "temp of air exiting evaporator" according to that thread.

So, which sensor is it? Part number? Location on the car?

 

OK, I am replying to this thread for later searching purposes for others that have the same problem.

I determined that the "Intake Temperature Sensor" that is mentioned in the link I posted in an earlier reply was bad. However, Nissan calls this sensor "Sensor Assy-Thermister" according to Courtesy Nissan website, with a product SKU of 27723-A33B001, in the "Cooling Unit" section of their OEM parts site. The price is only $10.99 as of today, 8/10/09.

To get to this sensor, you have to remove the entire glove box assembly. This involves removing about 6 screws from around that area, and then popping the clips on the right side of the glove box assembly (actually to the right of the actual glove box). Once you have that out, you will see this:


As you can see, the left is my auto climate control with the self-test showing the temp at 131 degrees. The sensor that needs to be replaced is the white plug right in the middle of the picture attached to the evaporator box. Its basically just a wire with a temp sensor on one end that clips to a fin on the evap, and a white connector on the other.

The difficult part of this is getting this wire out and the new one put in. While I dont know if I did the most efficient job, I basically just removed about every screw I could see from down there and then pryed the box open. I still couldn't get it to actually open up wide... Just wide enough to get most of my hand in there. I had some long nose needle nose pliers that got the old one pulled out with (its closer to the firewall) and then with the new one, I just stuck my hand in as far as possible and attached it to the evap with the clip that was on the old one.

While I was in there, I vacuumed out a bunch of old leaves and whatnot that was brought in and got caught through the vents on the other side of the evap. Smelled pretty bad and hopefully fixes the mildewy smell I sometimes got from the AC.

I also removed the front passenger seat to make it a tad easier to get to, instead of "sitting" in the seat upside down.

Hope that helps somebody.

 

Has anyone had the issue of the compressor not turning on when the climate control set to the lowest temperature? I had a mechanic vac the system and pumped new R134A into it. Still no luck.

He jump started the relay to the compressor and it worked fine. He said its probably a wire to the compressor from control unit.

Any thoughts?

 

Hi

I have exactly the same problem based on doing the auto diagnostics giving me that 131 degree reading and all of the symptoms, mainly no heat until turn the dial to 85. The installation looks like it might be pretty impossible for my clumsy hands. I was wondering if it would be a problem if you took the new sensor, clipped the wires and connected those attached to the white sensor with the old wires???

 

auto - AC
econ - heater

with auto, the AC compressor is always on

 

In my case once I ran the tests the cabin temperature was reading 135 F, the sensor is located behind the wheel behind a little grille on the right side, after I took the trim out I noticed it was "fixed" before by soldering something to the terminals of the connector that connects to the actual sensor... my guess is that it's a thermal resistance or something like that ??(looks like an electronics component resistance) anyway, the problem was that the component itself was shorting out because of how they positioned it, but the point is, yes, THERE IS A TEMPERATURE SENSOR THAT NEEDS CHECKING if you have the same problem... mine was guetto fixed, but it works, after I separated the connector's "feet" it read 65 with was around the temperature at the moment.... I hope someone else can benefit of this thread since it sucked to have cold air out when i needed heat!!!

 

so what was wrong with the sensor behind the wheel? did you just have to replace it or clean it?

 

Well like it says there, my guess is that the sensor is not working so they fixed it by bypassing it with some sort of electronic component (looks like a resistor to me). The problem with that is that the connector was shorting out, so I just had to re adjust them and that fixed the problem...

 

yeah I didnt know there was a sensor behind that panel, i removed mine as well and there was alot of dust built up on the thermistor thingy.

 

I know this is an old thread, but others have awoken it so I'll answer...

I have an i30 which had the same exact issues. There is a self-diagnostic mode you can use (spelled out in the FSM) when the climate control craps up. In this case, there is an interior air temperature sensor which clips onto the air conditioning condenser fins on the output side (opposite the fan) in the assembly behind the glove compartment.

The sensor itself was like $14 from the dealer, and the installation is fairly straightforward however it's in tight quarters.

I'm confused at people reporting the sensor "behind the wheel" because this all was on the passenger side behind the glovebox on my car. (2001 i30)

I'll be glad to answer any other questions that people have

 

I have an 1-35 in which there is a sensor behind the steering wheel right underneath the traction control button when u remove the trim panel. I seem to keep having heat issues one day it blows fine, the next day its cool air, then while driving it gets hot, but never hot at ide, tried bleeding several times, maybe next ill have to run water through the heater hoses to see if the core is clogged up or not.