HVAC Troubleshooting

[LXColorado]

Mudders,

I've had a few ask, so I think it warrants its own post - I assume more might have had/have this issue. Maybe this could end up in the FAQ, if enough people post solutions to HVAC problems (with pictures!).

PROBLEM: Temperature control for HVAC does not work. Cold is cold, 65 and above is HOT.

SOLUTION: Reconnecting the HVAC sensor and hose behind the driver's side kick panel.

PROCESS:

1. You're going to access the sensor and hose, located behind the four slits, under the ignition (picture 1).

2. Remove the plastic ring around the ignition (picture 2).

3. Locate the clip on the bottom of the kick panel. Make sure you undo the clip, and slide the plastic piece out (picture 3).

4. Slide the black plastic piece above the ignition out and up (picture 4).

5. Starting from the bottom of the kick panel, gently pry the piece out, moving your way up to the ignition. It should pop out.

6. Locate the sensor, and attach anything that's disconnected. The white hose falls off easily, so be gentle when putting things on, and pushing the plastic back in to place (picture 5).

7. Reverse your steps, to button everything back up.

Hope this helps anyone in need!

 

[Oakleyguy]

Nice work! Vote to FAQ

 

[2001LC]

@LXColorado thanks for pointing me here.
I've not yet inspected for this, but very good chance this is my issue. I'll let you know what I find.

 

[2001LC]

This was my issue, thanks again. It was very apparent someone had forget to reconnect the wire housing block and hose.

Clean the sensor while I had it out.

Found the wire block & hose trucked away in back. No way the just fell off!

Connected everything back up!

Auto climate control works just fine now.

 

[LXColorado]

Glad this worked out, @2001LC ! Looks to be pretty spot-on now. I vacuumed and recharged the A/C lines when I did this, as well. I figured it was time after 10 years. I've got a vacuum pump (and all accessories) you can use, if you decide to replace the refrigerant.

 

[yotasavg]

With the help of this thread, I finally drove to work today and enjoyed an HVAC system that functioned as nicely as my dual zone IS350 does on auto setting. Why did this take me three years?!

 

[REZARF]

@hoser pop this one in the FAQ brother.

@LXColorado thanks man this ones been driving me nuts. Gonna try it and post back.

 

[RunSupertramp]

Sorry to bring up an old thread. I’ve been digging around though and I can’t find an answer to my question anywhere.

Where does the hose go? I pulled my dash off today to clean the sensor and the hose is gone. Not just disconnected, but completely missing.

So what does the other end of the hose connect to?

Thanks-

 

[TJS8040]

Great and easy fix to an annoying problem, thank you, LXCO!

Sorry runsupertramp, I could not see other end of hose.

 

[bucfl]

This was a great thread to find! Thanks for the advice! The sensor was really dirty and the connector had fallen off. I had to remove the metal plate to find it. But this thread helped tremendously. Thanks a lot!

 

[Pinestreet]

Thank you everybody. My sensor and hose were disconnected also. Should have taken out the ignition cylinder while in there because I need mine rekeyed. I assume that should be pretty cheap at a locksmith. My 2002 came with one key for the ignition and one for the 3 door locks. I'm guessing a previous owner rekeyed the ignition but didn't bother to match it to the door locks? Any other possible explanation for the two different keys?

 

[Pinestreet]

Thank you everybody. My sensor and hose were disconnected also. Should have taken out the ignition cylinder while in there because I need mine rekeyed. I assume that should be pretty cheap at a locksmith. My 2002 came with one key for the ignition and one for the 3 door locks. I'm guessing a previous owner rekeyed the ignition but didn't bother to match it to the door locks? Any other possible explanation for the two different keys?

Update. I took the ignition cylinder to a local locksmith who charged me $30 to rekey it to my existing door key.

 

[blackdogcw]

I had an issue with the HVAC system on my 1999 Lexus LX470 where the fan was stuck on the lowest setting, even when the fan was set to high on the controller. I replaced the blower motor 2 years ago so I know that works. During the diagnostic cycle, I replaced the controller for the blower motor which did not solve my issue. My LX470 came with a built in cellular phone which I found out ties into the HVAC system. This tie in automatically adjust the fan to low when the phone is in use. I found on another forum that someone with the same issue found a short in the wiring for the phone system. I found an electrical schematic and determine the orange wire that goes into the connection at the bottom on the HVAC control panel is the tie in from the phone system. I cut this wire, tapped it off and problem solved! Hope this helps someone.