Climate control problem

Tiny
ERIC POWERS
  • MEMBER
  • 2 POSTS
  • 2003 HONDA CRV

Four cylinder all wheel drive automatic 87,000 miles.

Regardless of the temperature selected on the control dial, my temperature is either full cold (cold position) or full hot (all other positions). A/C works fine and coolant is obviously circulating. It becomes impossible to comfortably regulate the temperature during the winter. I replaced the heater control valve with no change; the cable from the manual knob moves the cable smoothly.

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Tuesday, December 1st, 2009 AT 6:53 PM

3 Replies

Tiny
KHLOW2008
  • EXPERT
  • 42,251 POSTS

Hi Eric Powers,

Try the following to see if you are able to retrieve any trouble codes.

General troubleshooting information:

How to retrieve a diagnostic trouble codes.

The heater control panel has a self -diagnosis function. To run the self -diagnosis function, do the following:

1 . Turn the ignition switch off.

2 . Turn the fan switch off, the temperature control dial on max cool and the mode control dial on vent.

3 . Turn the ignition switch on (II), then press and hold the re-circulation control switch. Within ten seconds while holding the switch down, press the rear window defogger switch five times. The re-circulation indicator blinks two times, then the self -diagnosis will begin. If there is any problem in the system after self -diagnosis is finished, the re-circulation indicator will blink the diagnostic trouble code (DTC) 7 through 13. When problems in the evaporator temperature sensor circuit are detected (codes 14 and 15), the A/C indicator will blink the DTC. If no DTC's are found, the indicator will not blink.


http://www.2carpros.com/forum/automotive_pictures/192750_HVACDTC03CRVFig07_1.jpg




http://www.2carpros.com/forum/automotive_pictures/192750_HVACDTC03CRVFig08_1.jpg



Canceling the self diagnosis function:

4 . Turn the ignition switch off to cancel the self -diagnosis function. After completing repair work, run the self -diagnosis function again to make sure that there are no other malfunctions.

Max cool position function:

5 . When the mode control dial is in the max A/C position, the heater control panel will automatically select the re-circulation mode and turn the A/C on. The re-circulation switch and A/C switch are disabled and cannot be turned off in this mode. If the control panel fails to function as described, replace it.

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Saturday, December 5th, 2009 AT 11:57 AM
Tiny
ERIC POWERS
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  • 2 POSTS

That was a great response and I appreciate it. I ran the diagnostic and no codes surfaced. I am thinking that perhaps there is a vacuum leak for the control that adjusts the cold air mix through the blower, and that it is stuck shut. The cold air results from a lack of coolant circulating as the temperature control also manipulates the heater control valve. It looks like it takes a contortionist to access that area of the system but I will give it another try.

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Sunday, December 6th, 2009 AT 7:29 PM
Tiny
KHLOW2008
  • EXPERT
  • 42,251 POSTS

Your appreciation is received with thanks.

The system does not use any vacumn lines for dontrols. If the heater and AC does not function as desired, the most likely problem would be the air mix motor. They could be intermittently malfunctioning.

Air max control motor test:

1 . Disconnect the 7P connector from the air mix control motor.

Note: Incorrectly applying power and ground to the air mix control motor will damage it. Follow the instructions carefully.

2 . Connect battery power to the No. 1 terminal of the air mix control motor, and ground the No. 2 terminal; the air mix control motor should run, and stop at Max Hot. If it doesn't, reverse the connections; the air mix control motor should run, and stop at Max Cool.

3 . If the air mix control motor did not run in step 2, remove it, then check the air mix control linkage and door for smooth movement.

" If the linkage and door move smoothly, replace the air mix control motor.
" If the linkage or door sticks or binds, repair them as needed.
" If the air mix control motor runs smoothly, go to step 4.


http://www.2carpros.com/forum/automotive_pictures/192750_AirMixMotor03CRVFig61_1.jpg



Fig. 61: Checking Air Mix Control Linkage & Door
Courtesy of AMERICAN HONDA MOTOR CO., INC.

4 . Measure the resistance between the No. 5 and No. 7 terminals. It should be between 4.2 to 7.8 kohm.

5 . Reconnect the air mix control motor 7P connector, then turn the ignition switch ON (II).

6 . Using the backprobe set, measure the voltage between the No. 3 and No. 7 terminals. 6 .

Max Cool-about 1 V
Max Hot- about 4 V

7 . If either the resistance or voltage readings are not as specified, replace the air mix control motor.

To remove the air mix motor, you would have to remove the underdash fuse/relay box.


http://www.2carpros.com/forum/automotive_pictures/192750_AirMixMotor03CRVFig62_1.jpg

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Monday, December 7th, 2009 AT 6:25 AM

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