Active grill shutters not working even after replacing motor.

[Scuba diver 71]

What are you using to measure it with?
A DMM is not really going to provide a sensible reading on a data stream.
You need to hook up an oscilloscope.
But anyways, 6-8 mV is in the dirt/background noise.

 

[Scuba diver 71]

Electronic clamp multimeter

 

[Cbty2050]

Even though some people reported U11E9 code with LIN bus voltage of 9V and mine is barely detectable I think it’s pretty evident that my ECU is bad. Replacing one is easy but programming keys etc is a chore. Any tips?

Most likely not an ECU.

 

[kapinallinen2]

Electronic clamp multimeter

That thing is using a low pass filter to eliminate any "high frequency" content, ie the data stream.
Would not be my first choice for troubleshooting the LIN bus.
But then again, you use what is on hand.
Looking at the pico screenshot provided by Cbty2050, you could try to average the peak vs. null and come up with WAG number to get a sort of a base line for a multi-meter DC reading.

 

[Scuba diver 71]

That thing is using a low a pass filter to eliminate any "high frequency" content, ie the data stream.
Would not be my first choice for troubleshooting the LIN bus.
But then again, you use what is on hand.
Looking at the pico screenshot provided by Cbty2050, you could try to average the peak vs. null and come up with WAG number to get a sort of a base line for a multi-meter DC reading.

I’ll hook it up to an oscilloscope tomorrow. I’ll let you know what I find. Thanks for all the good advice.

 

[kapinallinen2]

I’ll hook it up to an oscilloscope tomorrow. I’ll let you know what I find. Thanks for all the good advice.

Following your endeavor with interest.

 

[Scuba diver 71]

Hello, need some help with 2021 RAM 1500 5.7 AGS unit, while ago CEL light came on and when I scanned the car there was two codes, one for active air dam and the other for the active grill shutters. The air dam unit have been disconnected for a year and no CEL light was on so the problem had to be with the grill shutters. Bought a new motor for AGS unit and changed it, deleted the codes and after driving the CEL came back and the code was U11E9 - Lost communication with AGS. So then I checked the wires and they seemed all to be good, I have 12v power and 10v for LIN bus connection. When you plug in the motor, it slowly turns itself about half of the turn and then stops, that`s it. After when you drive it throws the same code.
So I after doing some research and reading forums I came to the conclusion that I need to fix AAD first. It seemed strange to me because It was disconnected for a year and I had no AGS fault codes and CEL was off, but anyway I decided to fix it and fit on a car. AAD code was off and tried to make it move so I raised the car wheels off the ground, put my phone filming and drive the car up to speed, after watching the video it actually moved out and back in, but U11E9 code came back. So I decided to swap the connectors because they both work with LIN bus, but realized that you can´t do that because wire order is different, and AAD wire is too short, but after doing some modifications I managed to do that, took the pins out from AGS and put them in the AAD unit and same thing with the AAD wires but needed to make them longer so I just soldered some extra wire there. After doing same driving test with wheels off the ground I got absolutely the same results, air dam moves and CEL on with the AGS communication missing code. I don´t know what to do anymore, AGS motor is brand new, AAD is working and both wires are good, so can it be the engine ECU or is there some procedure you need to do to calibrate it or something ?
Does anyone had same problem or know how to properly delete them so the CEL will stay off ?

Where did you connect and with what tool did you measure 10V on LIN bus?

 

[Scuba diver 71]

Following your endeavor with interest.

A cheap oscilloscope from Amazon is basically showing only some barely detectable background voltage. Nothing meaningful on that BUS LIN.

 

[kapinallinen2]

A cheap oscilloscope from Amazon is basically showing only some barely detectable background voltage. Nothing meaningful on that BUS LIN.

I would log into alldata and follow the troubleshooting instructions.

 

[CaptainKlossJ23]

I thought i should share my experience with U11E9. After reading a lot of post's i have decided to check the wiring first. Nothing was wrong with the plug or wiring. Actuator was second - replaced with aftermarket one. Once the whole front was disassembled i have checked that there was nothing wrong with the shutters mechanically. Code still there after. Took it to the dealer since i have found my lower Air Dam replacement letter. Check engine showed after driving in a storm so that make sense (lower Air Dam controller was flooded). After installing a new one dealer came back with 1140.0 for the shutter replacement as the code was still there. Denied that. Today i have connected original old actuator without installing it at the shutter system. Code cleared, so far it's gone.

 

[Pikeman_66]

I thought i should share my experience with U11E9. After reading a lot of post's i have decided to check the wiring first. Nothing was wrong with the plug or wiring. Actuator was second - replaced with aftermarket one. Once the whole front was disassembled i have checked that there was nothing wrong with the shutters mechanically. Code still there after. Took it to the dealer since i have found my lower Air Dam replacement letter. Check engine showed after driving in a storm so that make sense (lower Air Dam controller was flooded). After installing a new one dealer came back with 1140.0 for the shutter replacement as the code was still there. Denied that. Today i have connected original old actuator without installing it at the shutter system. Code cleared, so far it's gone.

Sounds to me the dealer doesn't even know how to fix these trucks. What A shame

 

[Cbty2050]

I thought i should share my experience with U11E9. After reading a lot of post's i have decided to check the wiring first. Nothing was wrong with the plug or wiring. Actuator was second - replaced with aftermarket one. Once the whole front was disassembled i have checked that there was nothing wrong with the shutters mechanically. Code still there after. Took it to the dealer since i have found my lower Air Dam replacement letter. Check engine showed after driving in a storm so that make sense (lower Air Dam controller was flooded). After installing a new one dealer came back with 1140.0 for the shutter replacement as the code was still there. Denied that. Today i have connected original old actuator without installing it at the shutter system. Code cleared, so far it's gone.

I would double check wiring at AGS and at AAD, just had the lin bus wire corroded about 4 inches from AGS causing issues. This came from another shop who installed new AGS and AAD.

 

[kapinallinen2]

just had the lin bus wire corroded about 4 inches from AGS causing issues.

How can that even happen? Where are these harnesses being made in?

 

[Cbty2050]

How can that even happen? Where are these harnesses being made in?

There is a zip tied push retainer at that point, I think that stresses that tiny *** wire.

 

[Scuba diver 71]

A cheap oscilloscope from Amazon is basically showing only some barely detectable background voltage. Nothing meaningful on that BUS LIN.

Hello. So after several attempts of replacing active grill shutter motors, wires, measuring continuity and voltage, you name it, I gave up and went to the dealer. They found a corroded LIN BUS wire between the big connector behind the bumper on the left front side and ECU. They fixed the wire and I am back in business. Paid $600.
No idea why do these wires corrode. Sounds like a common issue.