Code U1511.00, A/C problem?

Tiny
PAWEL_N
  • MEMBER
  • 2016 CADILLAC ESCALADE ESV
  • 6.2L
  • V8
  • 4WD
  • AUTOMATIC
  • 50,000 MILES
Hello,
I have a problem with the A/C. It is not working sometimes. Could you please write wiring diagram for all items connected to A/C sensors and LIN BUS? Where is A/C controller/driver? What does it mean U1511.00? When I connected the car to scan tool there was information, that there is not connection to AC/LIN. What shall I check or do? I am waiting for your reply.
Have a nice day,
Pawel
Thursday, November 28th, 2024 AT 9:15 AM

9 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,321 POSTS
The first thing I would do is check the battery voltage which should be 12.4 standing, this guide can help:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Replace the battery if it fails the test and clear the codes.

U1511: Lost Communication With LAN.

Next, I would check the fuses using this guide:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Here is the fuse locations and I have included the AC system wiring diagrams so you can see how the system works, and the sensors involved. Check out the images (below). Please let us know what happens. Please check the fuses with the key on.
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Friday, November 29th, 2024 AT 11:30 AM
Tiny
PAWEL_N
  • MEMBER
  • 178 POSTS
Thank you for your reply. I checked all your suggestion and all looks OK.
But I observe more toroubles:
1. One front parking sensor in bumper was not working. Three pcs. Was working, one does not. I replace it and not any in front and not any in rear is working now!
2. The blinds (shutter) in front of cooler is not working (the temperature outside is under 32F).
3. The low range sensor in front bumper is probably not working, because the do not stop in front of an barrier (there is set "stop the car" in menu while barrier in front).
It all looks like a problem with connection in wiring front bumper with some module in car. Where is this module located in car?
What is the wiring in front bumper?
The car is after accident and the front bumper was replaced. I am not sure if all was well fix.
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Monday, December 2nd, 2024 AT 1:25 AM
Tiny
KEN L
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I was going some research and the EBCM can be out which might cause these issues. Here is the location of the unit so you can get a preprogrammed unit by searching Google or Ebay. Check out the images (below). Please let us know what happens.
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Monday, December 2nd, 2024 AT 9:54 AM
Tiny
PAWEL_N
  • MEMBER
  • 178 POSTS
Thank you for your reply.
1. Is it safe to replace EBCM with other used one? No one sensor in car will lost "memory"? Should I program the new EBCM or should it start working at once?
2. Could you please add wiring diagram between front bumper and EBCM? EBCM have some different connectors. Which one connector (plug) on EBCM goes to front bumper.
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Monday, December 2nd, 2024 AT 11:24 PM
Tiny
KEN L
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The replacement BCM needs to be programmed before it will work so you can't just plug one in. You can get them preprogrammed if you search google or eBay for a service that does so. Here are the wiring diagrams for the BCM, I would recheck the fuses for the BCM as well. Check out the images (below). Please let us know what happens.
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Tuesday, December 3rd, 2024 AT 10:03 AM
Tiny
PAWEL_N
  • MEMBER
  • 178 POSTS
Hello,

The mechanic found the problem with code U1511.00 - it is a problem with the front bumper active shutter. I do not have an original shutter. This shutter should be controlled by two actuators. I connected other two actuators and the error switched off. I bought the new one shutter controlled by only one actuator and the error is on. But I do not know what is the right part number for shutter with two actuators for my car. The VIN is 1GYS4KKJ4GR132788.
Could you please type the right part number for active shutter with two actuators?
I am waiting for your reply.
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Tuesday, March 25th, 2025 AT 2:56 AM
Tiny
KEN L
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Hmm, no information I have or on the web says anything about the U1511 code being the shutters? Here are the shutter codes FYI.

U codes are for the network, here are the shutter part numbers, please let me know how it goes. Check out the images (below).
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Tuesday, March 25th, 2025 AT 11:11 AM
Tiny
PAWEL_N
  • MEMBER
  • 178 POSTS
Thak you for your reply. But the number GM1352153 is described as Front Driver Side Interior Door Handle (Standard Line) for Chevy. Are you sure that is it part number for shutter?
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Tuesday, March 25th, 2025 AT 11:33 PM
Tiny
KEN L
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The part number info came from Ai so no. They don't give the part number in AllData. There is only one mention of the shutter on the web for this code. The rest are all over the map. I would call the dealer for the part number, if it works, please let me know I am interested. Be sure to clear the cods once the repair is made.
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Thursday, March 27th, 2025 AT 8:27 AM

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