Random A/C Problem 1999 Limited

[takumi]

I have an A/C problem on my 1999 Limited.

The A/C randomly works or doesn't work. The A/C blows cold when it works. Sometimes when I start my 4runner I get a single blinking digit on the front display and the A/C does not work.

To get it to work I have to shut the 4runner off, I have to put the key in the ON position without starting it, i have to turn the key one click left very quickly and then back to the ON position. I have to keep repeating this sequence until I see 75 on the display and the fan symbol. Once I see this I can start the 4runner and the A/C works properly.

Any ideas what the problem could be and how to fix it?

Thanks for any help.

 

[JRZEE2000TR4LTD]

Sounds like something is wrong with the digital control. Do the buttons work properly on the control?

 

[BamaDrewski]

These auto climate control units have a "self-diagnostic" code system. Turn the vehicle off with the key in the ignition. Hold down the "Auto" and "Fresh air/recirculate" (Right above the auto AC button) button at the same time. While holding them down, turn the key until you see a display of numbers going through the auto climate control. If there is an issue, it will throw a code. It could also be your display controls are worn out. (Cheap fix on Ebay "send and repair" service......)

The three sensitive components (sensors) for the system are the outside air sensor, the solar sensor (the red plastic dome on the dash in front of the driver's position) and the interior air sensor (below the ignition in the lower driver's side kick panel). It could be some of these sensors are shot and if so - the codes should tell you.

Here is the list of codes:

11: Room temperature sensor circuit
12: Ambient temperature sensor circuit
13: Evaporator sensor circuit
14: Engine coolant sensor circuit
21: Solar sensor circuit
23: Pressure switch circuit
31: Air mix damper position sensor circuit
32: Air inlet damper position sensor circuit
41: Air mix control servomotor
42: Air inlet control servomotor

Hope this helps man....

 

[BamaDrewski]

These auto climate control units have a "self-diagnostic" code system. Turn the vehicle off with the key in the ignition. Hold down the "Auto" and "Fresh air/recirculate" (Right above the auto AC button) button at the same time. While holding them down, turn the key until you see a display of numbers going through the auto climate control. If there is an issue, it will throw a code. It could also be your display controls are worn out. (Cheap fix on Ebay "send and repair" service......)

The three sensitive components (sensors) for the system are the outside air sensor, the solar sensor (the red plastic dome on the dash in front of the driver's position) and the interior air sensor (below the ignition in the lower driver's side kick panel). It could be some of these sensors are shot and if so - the codes should tell you.

Here is the list of codes:

11: Room temperature sensor circuit
12: Ambient temperature sensor circuit
13: Evaporator sensor circuit
14: Engine coolant sensor circuit
21: Solar sensor circuit
23: Pressure switch circuit
31: Air mix damper position sensor circuit
32: Air inlet damper position sensor circuit
41: Air mix control servomotor
42: Air inlet control servomotor

Hope this helps man....

Just checked the FSM and the "1" on your display (from your photo) says the "air mix damper" is "0% open". Probably means the code 31 that your air mix damper sensor is shot....

 

[takumi]

Thanks for the help.

I followed your steps and what i get is it's repeatedly blinking... 21: Solar sensor circuit


So what would be the best approach to fix this. Is this a part I can buy online?

These auto climate control units have a "self-diagnostic" code system. Turn the vehicle off with the key in the ignition. Hold down the "Auto" and "Fresh air/recirculate" (Right above the auto AC button) button at the same time. While holding them down, turn the key until you see a display of numbers going through the auto climate control. If there is an issue, it will throw a code. It could also be your display controls are worn out. (Cheap fix on Ebay "send and repair" service......)

The three sensitive components (sensors) for the system are the outside air sensor, the solar sensor (the red plastic dome on the dash in front of the driver's position) and the interior air sensor (below the ignition in the lower driver's side kick panel). It could be some of these sensors are shot and if so - the codes should tell you.

Here is the list of codes:

11: Room temperature sensor circuit
12: Ambient temperature sensor circuit
13: Evaporator sensor circuit
14: Engine coolant sensor circuit
21: Solar sensor circuit
23: Pressure switch circuit
31: Air mix damper position sensor circuit
32: Air inlet damper position sensor circuit
41: Air mix control servomotor
42: Air inlet control servomotor

Hope this helps man....

 

[takumi]

I just wanted to take a second and update this thread.

After doing some research the Digital Climate Control was faulty. Not all of the buttons were working. Turns out this is a common problem with the 4runners and tacomas that have this Digital Climate Control.

So long story short I removed the Digital Climate Control, shipped it to a company on eBay that specializes in repairing these Digital Climate Controls. They replaced all the components inside the unit and tested it to be sure it was working properly before they shipped it back to me. The total cost was $100.00

Total time for me to ship it to them and get it back was about a week. Needless to say I'm really happy now cause it works great. All the functions work properly now. And I got cold A/C :dance:

Sounds like something is wrong with the digital control. Do the buttons work properly on the control?

 

[LittleCaesar]

Good to hear, but is 77 the coldest temp for ya with the AC on?

 

[takumi]

I think it goes down to 65 and then it just says cold on the display.

Good to hear, but is 77 the coldest temp for ya with the AC on?

 

[Chrischmieder]

Need help trying to get heat

These auto climate control units have a "self-diagnostic" code system. Turn the vehicle off with the key in the ignition. Hold down the "Auto" and "Fresh air/recirculate" (Right above the auto AC button) button at the same time. While holding them down, turn the key until you see a display of numbers going through the auto climate control. If there is an issue, it will throw a code. It could also be your display controls are worn out. (Cheap fix on Ebay "send and repair" service......)

The three sensitive components (sensors) for the system are the outside air sensor, the solar sensor (the red plastic dome on the dash in front of the driver's position) and the interior air sensor (below the ignition in the lower driver's side kick panel). It could be some of these sensors are shot and if so - the codes should tell you.

Here is the list of codes:

11: Room temperature sensor circuit
12: Ambient temperature sensor circuit
13: Evaporator sensor circuit
14: Engine coolant sensor circuit
21: Solar sensor circuit
23: Pressure switch circuit
31: Air mix damper position sensor circuit
32: Air inlet damper position sensor circuit
41: Air mix control servomotor
42: Air inlet control servomotor

Hope this helps man....

I followed your instructions and came up with a 21, 41, 42... what parts do I need? I looked up the parts listed and it's is pulling up the same thing. I swapped out the servo at the bottom of the dash next to the center console on the passenger side front seat. What is the the other part and where does it go? Not concerned with the 21 code yet..

Any response?