2001 QX4 a/c self diagnosis question

[tomR]

My 2001 qx4 factory service manual refers to a "self-diagnostic" test for the ac system. I tried to do this test when my a/co quit cooling the suv.

The service manual shows a different a/c control unit than the one I have and the test wont run as described. The temp arrows are to be used to perform part of the test and instead of temp arrows I have a temp "knob." When I tried to to use the knob instead of the buttons for the test, I got error codes that arent listed in my service manual so I'm not sure if the test was done correctly or not.

Can anyone tell me how to run the test with the different a/c control unit? And -why is my ac control unit different then the one in the service manual? I do have a factory manual.

Thanks,Tom

[elwesso]

Basically every nissan that has automatic climate control works the exact same way.

Instead of using the buttons you just turn them clockwise.

What codes did you get?

[tomR]

Hi Elwesso-Thanks for getting back to me on this. I'm kind of at a dead end.

These codes appeared one at a time, as I turned the temp. adjuster:234151None of the codes "blinked" respectively and all of the codes were out of the range referenced in my service manual. Any sugesstions?Tom

[elwesso]

Did the 2 and the 3 just stay at 2 and 3 or did they ever blink 20 or 30? You have to let them sit for like 30 seconds or so.

41 is used to test different modes so you dont really need to do anything with that. 51 is used to view the temp sensor readings...

[tomR]

The numbers appeared individually and I didnt leave any of them on very long. I only cycled thru them -hardly a second or two. I can try again tomorrow and let it sit on each number for a while if you think it will be helpful.Tom

[elwesso]

Let it sit there for about 30 seconds, it WILL flash a 2nd digit on the 2 and 3. The system doestn actually just spit out codes, it checks everything right then.

[tomR]

Ok -I see from the manual that the error code range is from 21 to minus26. Looks like if I can get a second digit I'll be able to move on from there.

Thanks a bunch.