Climate control not working

BOBSGAMES

MEMBER
2011 TOYOTA SEQUOIA
V8
RWD
AUTOMATIC
22,000 MILES

AC will get stuck in certain modes and settings. For example, right now it is stuck at 70 degrees on low. I cannot alter the temp, fan speed, cannot turn on/off, cannot turn defroster on/off, cannot turn rear ac on. Sometimes when I restart the car (maybe even several days later) it will be responsive, like new again. Sometimes it gets frozen in the off position. Same thing as above. My wife had to pull over one day on a cold January day because the windows fogged up so much she could not see and could not get anything to work.

Don McGill Toyota at Katy freeway near Dairy Ashford has replaced the AC control panel and an amplifier on two separate occasions. After each replacement, the control panel worked for a week to 10 days. Now, it is not working again. They seemed perplexed, and I am getting irritated. Their "master" mechanic also had no answer. They seem content to replace parts without diagnosing the actual issue. Any ideas?

7 Replies

HMAC300

MECHANIC
48,601 POSTS

This sounds more like a bad ground or connection which is common. Here is a guide to help you check the wiring and the HVAC wiring diagrams below so you can see how the system works and which wires to test.

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (Below). Please let us know what happens.

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Tuesday, March 25th, 2014 AT 6:21 AM

BOBSGAMES

MEMBER
3 POSTS

Thank you for the response. Why would the battery be an issue? I did disconnect the batter cables last night and cleaned off some corrosion. I thought disconnecting power may reset the computers or something. All it did was reset the AC to the off position, and now I cannot turn anything on. The batter is three years old, but it seems to be working well - car turns over quickly with every start.

What/Where is the left kick panel?

Thanks again!

Bob.

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Tuesday, March 25th, 2014 AT 8:02 AM

HMAC300

MECHANIC
48,601 POSTS

Left kick panel is where your foot goes on the side take that off and there is wiring under it. Look for a black wire that is screwed into metal. The battery being low means it wold have low voltage and not having good voltage really screws these modules up. Look in your manual and see if there is anything about reseting your control panel otherwise it will need scanning.

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Tuesday, March 25th, 2014 AT 9:30 AM

BOBSGAMES

MEMBER
3 POSTS

Thanks, Hmac. I will check out the wire and if that is not it, then I'll go ahead and replace the battery.

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Tuesday, March 25th, 2014 AT 10:22 AM

HMAC300

MECHANIC
48,601 POSTS

Have the battery checked first autoparts and tire stores do for free don't replace parts that aren't needed. If you cable ends were corroded badly that would give an indication of a bad battery as well. Just looking at the symptioms int eh manual they list quite a few things but mostly amplifier is a biggie other than control which you said has been replaced a couple of time.S also c check the ECU-1G fuse which I've pointedout in pic. That may be why it's not coming on.

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