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I’m still battling the A/C in my 2004 Tahoe. Is there a scanner that I could buy that reads more than basic engine problems or emissions problems without spending a fortune? I’m told the free scans at local parts stores on diagnose emission or safety related codes. Where to buy and what to look for appreciated.
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As far as I know….. no there isn’t.
What tool you would use depends on your problem. If it is a problem with the climate control system (ie doors/actuators, fan, interface, or other components inside the cab) you may be able to have a dealer look into the Body Control Module. Only the dealer has these. Even if you could buy one, they are probably a few thousand dollars.
What are your symptoms?Temperature randomly changes from cold to hot with no warning. When it is cold it is very cold(45 degrees) but when you cut car off and restart rarely is it cold. After a restart it blows at 90 degrees. Have replaced blend doors and that did not seem to help. Blows same temp out of all vents(front, back, left and right). When it is blowing cold sometimes it randomly switches to heat when nothing was done to temperature settings.
Did you replace the blend door and the servo? If you replaced the servo with it, you may need to re-learn the servo.
Like I said: The only tool that (I am aware of) that would be helpful is a BCM scanner, but only dealers have those. So you may need to take it to the dealer.What is a servo and where is it located? I only changed the blend door actuator. The blend door actuator was held in by 2 screws and an electrical connector. Thanks
Actuator/servo, same thing. Does the actuator require the “re-learn” procedure? Some of them do, especially with GM. Normally you just unhook the battery for a period of time, then hook it back up, but some of them have different procedures (like turn the key to run and off 3 times then hold the gas pedal). You might want to call the dealer and ask. Unless they’re total “D-bags” they will tell you.
This is a good budget scan tool that will read all systems. they’re are slightly cheaper versions if you want just the data for domestic vehicles but I personally Like to have the option for everything. the platform is quite good if you wish to expand as well I have DPF regen software EPB and Oil light reset software all added to my MD802.
You can buy a Tech2 which was the GM OE tool until a few years ago. Snapon Solus models and better will cover most of your needs if not all, but there is a price. OTC is junk, they make a good wheel chock, and that’s it. I keep my old OTC around for the pre-OBD2 stuff, as it’s more reliable than newer scan tools that are only software compatible
The actuator needs to be recalibrate with Tech 2. It will recalibrate all actuators to relearn there positions. Just take it to the dealer and have them recalibrate them. It’s cheaper then buying a scanner that can do that. There is also a function test have them run that test. It only take 1-2 minutes for the function test and anther 1-2 to recalibrate the actuators.
[quote=”kscott1994″ post=136446]What is a servo and where is it located? I only changed the blend door actuator. The blend door actuator was held in by 2 screws and an electrical connector. Thanks[/quote]
Ok, so as you might have guessed by now you need to perform a re-learn. It’s pretty easy, but you’ll need a wiring diagram. Just find all the fuses that go to the HVAC module. Leave them out for a minute or 2. Re-install fuses and confirm fix. When you first cycle the key you will hear everything running through their operating ranges (re-learning) DO NOT touch anything HVAC related until you are sure they are done. Now everything should work fine. This is the fix on many GMs so it likely will work for you.
Here is Autel MD802 GM vehicle list: http://121.40.141.249:8081/Download/Veh/ELITE/Enhanced/GM/en_MaxiDiag_E_GM%20FUNCLIST.pdf
You need to check if the tool will work on your car before buying it. If your car model and system is not listed, it means the tool won’t work on your car…
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