The temperature control does not work. Cannot get heat into the car. The knob turns with less resistance than when it worked correctly

031 B1251 IN-CAR TEMPERATURE SENSOR OPEN GO to Pinpoint Test B
PINPOINT TEST B: IN-CAR TEMPERATURE SENSOR INOPERATIVE B1 CHECK SENSOR RESISTANCE

NOTE: An open sensor will cause warm air discharge at 18°F (65° C) setting. A shorted sensor will cause cool discharge air at 29°F (85°C) setting.

• Disconnect the A/C ambient air temperature sensor.
• Using an ohmmeter, measure the resistance across the sensor terminals and compare the readings with the following sensor resistance table:
  
  Approximate Temperature Sensor Resistance Acceptance Range 10-20°C (50-68°F) 37K-58K ohms 20-30°C (68-86°F) 24K- 37K ohms 30-40°C (86-104°F) 16K-24K ohms

Are resistance values within the specified limits?
Yes No GO to B2 . REPLACE A/C ambient air temperature sensor and bracket. RESTORE vehicle. RETEST system. B2 CHECK ASPIRATOR INSTALLATION

• Gain access to automatic temperature control sensor.
• Check for proper installation of automatic temperature control sensor hose and elbow.

Is aspirator installed properly and hose connected?
Yes No GO to B3 . SERVICE automatic temperature control sensor hose and elbow as necessary. RESTORE vehicle. RETEST system. B3 CHECK CIRCUIT 470 (PK/BK) AT AUTOMATIC TEMPERATURE CONTROL SENSOR

• Turn ignition switch to the RUN position.
• Turn EATC module to NORM A/C position.
• Disconnect automatic temperature control sensor.
• Using a voltmeter, check Circuit 470 (PK/BK) for voltage at sensor connector.

Is voltage 5 volts?
Yes No GO to B5 . GO to B4 . B4 CHECK CIRCUIT 470 (PK/BK) FOR OPEN

• Disconnect connector C227 at EATC module.
• Using an ohmmeter, check Circuit 470 (PK/BK) between EATC module and automatic temperature control sensor for open.

Is there 5 ohms or less?
Yes No SERVICE Circuit 470 (PK/BK) for open. RETEST system. GO to B5 . B5 TEST CIRCUIT 470 (PK/BK) FOR SHORT

• Using an ohmmeter connected to a good ground, connect other lead to EATC module connector Pin C227 , Circuit 470 (PK/BK).

Is resistance less than 10,000 ohms?
Yes No SERVICE Circuit 470 (PK/BK) for short. RESTORE vehicle. RETEST system. GO to B6 . B6 TEST CIRCUIT 790 (W/O) FOR OPEN

• Using an ohmmeter, connect one lead to EATC module connector Pin C227 , Circuit 790 (W/O) and other lead to automatic temperature control sensor Circuit 790 (W/O).

Is resistance 5 ohms or less?
Yes No GO to B7 . SERVICE Circuit 790 (W/O). B7 TEST CIRCUIT 790 (W/O) FOR SHORT

• Using an ohmmeter connected to a good ground, connect other lead to EATC module connector Pin C227 , Circuit 790 (W/O).

Is resistance less than 10,000 ohms?
Yes No SERVICE Circuit 790 (W/O) for short. RESTORE vehicle. RETEST system. REPLACE EATC module. RESTORE vehicle. RETEST system.

Easiest place to start is checking for a broken control knob. Pull the knob off and see if it is cracked/broken on the back side. You can turn the metal control rod then by hand to see if it works. If no problem found there, you will have to check for a blend door motor/actuator that controls heat/cooling attached to the heater box under the dash for proper operation

Hi Sharon, I'm glad to help. Your 2000 year doesn't have a motor for the temp door. It operated by a cable running from the control head to the temp door and you work it manually. If you can't control the temperature from hot to cold, sometimes the cable come off or breaks. Here how you can see the cable to see if its working. Remove the radio and right behind it you will see the cable attached to the door, while watching it move the temp lever from hot to cold and watch it. If it is moving then its most likely out of ajustment. If it is not moving, then you'll need a new cable. Just in case it is moving, I'm attaching the instruction on how to adjust it below. Hope this helps and have an awesome day Sharon!

TEMPERATURE CONTROL CABLE

Any time the heater-A/C control or the temperature control cable are removed and/or replaced, the following procedure must be performed.

1. The temperature control cable housing and core must be installed at both the heater-A/C control and the heater-A/C housing ends, and the heater-A/C control must be installed in the instrument panel. See Heater-A/C Control and Temperature Control Cable in the Removal and Installation section of this group for the procedures.
2. Rotate the temperature control knob on the heater-A/C control so that the knob pointer is in the 12 o'clock position.
3. Pull the temperature control knob straight out from the heater-A/C control base until the perimeter of the knob (not the knob pointer) protrudes about 6 millimeters (0.25 inch) from the face of the control base.
4. Rotate the temperature control knob to the 1 o'clock position. Push in on the knob slightly and continue rotating the knob to its full clockwise stop. The knob pointer should be aimed at a position about 8 millimeters (0.315 inch) beyond the end of the graduated red strobe temperature control graphic on the face of the heater-A/C control base. If the knob is not pointed to the correct position, go back to Step 2 and repeat the adjustment procedure.
5. Rotate the temperature control knob counterclockwise until the knob pointer is in the 12 o'clock position again.
6. Push the temperature control knob straight in towards the heater-A/C control base until the perimeter of the knob (not the knob pointer) is flush with the face of the heater-A/C control base.
7. Rotate the knob to its full clockwise stop again. The knob pointer should be aimed at the end of the graduated red strobe temperature control graphic on the face of the heater-A/C control base. If OK, go to Step 8. If not OK, go back to Step 2.
8. Rotate the knob to its full counterclockwise stop and release the knob. If the knob springs back from the counterclockwise stop, the self-adjuster clip that secures the temperature control cable to the blend-air door lever is improperly installed. See Temperature Control Cable in the Removal and Installation section of this group for the procedures. If the knob does not spring back, the temperature control cable adjustment is complete.

Search for my prior solution under Nitram2. It's almost always broken wires in a 3-wire harness feeding the knobs. Toyota will skim you close to $1000 for this, claiming that you need to replace the control board. It's an easy half-hour soldering job.

If you can pull the knob off the heat and look inside to see if the knob is broken out. if not you may have a broken switch.

Try locating the heater hoses. Start with the vehicle cool and turn it on and wait till the engine temperature reaches the correct temperature. This should send fluid through the heater hoses. Feel the heater hoses for a change in temperature. If there is no change in heat after a while the problem is in your thermostat. If one heater hose is hot while the other is not than the problem is in the heater block. If both hoses are heating up then the problem is probably in the climate control knobs or wiring that controls the blend doors or may even be the blend doors are broke and are not opening correctly to allow heat into the vents. This could also be a problem if the ac does not get cool either.

sounds like a bad blend door motor common problem. bolted to side of heater box.good luck.

If the blower is blowing air just fine, but you cannot control the temperature, you need to listen to air coming from the vents while turning the temperature from hot to cold. If you do n ot hear any change in airflow, then you may a temperature door in the dash broken. this is becoming a common problem on the Equinox

Tech JK
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You have to locate the cable between the heater core box and dash control knob most likely it is hung up someplace in between if you can straighten it out it will give you more cable length also look to see there may be a loose spring that need to be reattached.
wear safety glasses and get a good light you will need screw drivers needle nose pliers snap ties to hold cable in place

The first knob controls the temperature. Turning it counterclockwise will lower the temperature, clockwise will raise it. Pressing the button will turn on the circulate function (recirculates the air from the cabin).
The second knob controls the fan speed. Counterclockwise will reduce the fan speed, clockwise will increase it. Pressing the button activates the A/C compressor (allows colder temperatures).
The third knob controls the flow direction. Each picture indicates where the flow will go. Pressing the button activates the rear defoggers (in some models, it will also activate the heated side mirrors).