Cadillac Repair Questions? Ask a Mechanic for Answers ASAP
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I am Derek, an ASE master technician and will be happy to assist you with your Cadillac Escalade.
Are you referring to the rear air-conditioning system?
Does the temp switch to cold when you manually turn the temp door by hand? Sometimes the temp door will break internal in the rear A/C unit.
And for the actuator not moving. I am sorry to say if you replaced the module it will need to be reprogrammed at a dealership. Or a shop that can program GM vehicles. It will not work until the module gets programmed to the vehicle and the actuators relearned.
When manually moving the temperature door you should be able to feel the door stop when turned back and forth. If it spins freely the door has likely broken.
What I do to turn the temp door, is just remove the screws from the actuator and turn the actuator by hand to move the temp door. You will feel the door hit the stops turning back and forth.
You are correct about pulling the rear HVAC fuse for 30 seconds, turn on the vehicle and wait 2 minutes without moving the HVAC controls. This will recalibrate the actuators.
This is not considered reprogramming. The software inside the rear HVAC controller needs to be reflashed with a laptop software and requires special tools.
Turning the temp door one direction will place the system into full cold and the other direction will blow hot air.
You are correct the temp door actuator should move when turning the tempeture dial.
But the problem is it will not work until the software is reflashed for the rear HVAC module. This is due to the fact that you have replaced the module.
The old module could still be the problem.
Do you have a scan tool that can communicate with the rear HVAC system?
Ok, so one very important thing that needs to be checked before installing the HVAC actuators is checking they have not moved out of the proper range.
If you look at the back of the actuator do you notice the 2 lines and the 1 notch?
ok sounds great let me know what you find. If the door is broken, it will set a fault code and always blow hot or cold air. and this will cause the actuator not to move.
ok great that is good news that the door is not broken internally inside the heater box unit.
before the actuator is installed move the blend door by hand to the middle position.
Then you will need to put the actuator back together with the notch on the knob in the middle of the 2 lines at the top of the actuator. If that notch moves outside of those 2 lines it will set a fault code and not work correctly.
After reinstalling the actuators in the correct position, try re calibrating the system with the old module. If there are no other problems the system should operate normally.
I hope it works!! Just be sure not to move any of the heater controls after re-installing the fuse for at least 2 minutes.
Normally what happens is the notch will move past the 2 lines on top of the actuator then this causes the system to not work.
Inside the actuator is a position sensor that is used by the HVAC module and it needs to be in the proper position to work correctly.
Well you have already replaced the actuators correct? The actuator is what normally fails.
that is normal, just watch the actuator and make sure the notch does not move past the lines.
It could if it starts working. Unless the position sensor inside the actuator has failed. The only way to tell if it is reading correctly is with a scan tool.
That's great! then you have installed it in the proper position.
Have you tried using both the temp controls? There should be one up by the windshield and one at the rear seats.
ok the actuator may still be out of alignment, sorry this is hard to explain.
Are there 2 notches on the nob?
And how many lines on the cover?
ok thanks there are a couple different configurations. You will need to align the notch with the middle mark on the cover.
When I am at work tomorrow I can take a picture of one to make it clearer if needed.
If this is correct try using the new actuator.
ok well at this point you have covered pretty much everything that can be done. Try using the new actuator, if this still does not work you will need to get that new module installed and reprogrammed. With a new module and the software programmed to the vehicle, it should work normally.
No, unfortunately, you can not install it that way. The lines are there to keep the position sensor inside the actuator in the correct position. If it moves outside of that range it will not work.
It proves there is a fault code stored in the system not allowing it to move.
If the new actuator has moved outside of the lines then it was not installed in the correct position when the system was calibrated.
I was just going to suggest you try that. Like i said before just ensure when the system is calibrating it does not move outside of those lines. If it does you will need to try it again.
well darn, instead of just removing the fuses try removing the battery cables and touching them together for 1 minute. Reconnect the cables, turn the ignition switch on, do not move the HVAC controls, wait 5 minutes and try changing the temp.
If disconnecting the battery cables does not help the module is the only other component that could be at fault.
The module will need to be replaced and reprogrammed to the vehicle.
We have covered everything that can be done, and it seems you are doing everything right. Ohh ok just remove one cable and leave it disconnected for 30 minutes then.
I would suggest leaving the new one in when disconnecting the battery. Also ensure the new actuator has the same amount of pins as the old one. You may have a wrong part.
yeah you are right it is most likely the module if it still does not move.
I am going to call it a night! I will be back on tomorrow to check back in.
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No just remove the neg cable. I am glad you told me about the stereo system.
If you touched the cables together and you have a capacitor it would not turn out well. Just leave the one cable off for 30 to 40 minutes.
You might even want to wait even longer having the aftermarket stereo. The capacitors can hold voltage for a long time.
Thanks for your patience have a good night.
I am checking back in. Have you had any luck getting the rear air conditioning to work on your Escalade?
I mentioned the door could be broken. Sorry to hear it was the housing assembly. I was just trying to walk to through all of the steps to diagnose the actuator and check the doors. It is not that bad of a job to replace the unit. If you have the a/c system drained by a shop you can replace the housing assembly yourself if you are up to it.
Yeah, i get that, way too hot in Pheonix. I lived there when I went to automotive school; know what you mean I never left AC.
You said when we were talking you moved the door by hand and got it to blow cold air. I would just move the actuator in the cold position, install it and leave the connector disconnected so it doesn't move.
That's an excellent idea on the second opinion.
The air ride is a common problem for GM vehicles. The compressor stops working, causing the rubber bladder on the rear shocks to tear.
At my shop, we buy shocks and compressor rebuild kits for a much lower price than the GM units. I just cant think of the name of the company right now. I will find out for you on Monday when I am back at work.
That is expensive, you can find a Dorman compressor for 200 dollars and then shocks for 350 on Amazon.
As for the steering wheel controls, all you need to do is disconnect the battery, and remove the steering wheel. You won't set off the airbag by accident by disconnecting the battery.