Active grill shutters not working even after replacing motor.

[Yuki]

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 ?

 

[kapinallinen2]

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 ?

I can recommend the combination of Alldatadiy, alfaobd, obdlink MX+ and a SGW bypass cable.

 

[Scuba diver 71]

The damn U11E9 code had me take the entire front grille off (so unnecessarily complicated), replace the AGS motor, replace the pig tail connector to the AGS motor and the code hasn’t disappeared. I ran continuity test from AGS motor plug back to a first major harness connector located behind the front bumper on the driver side. Photo attached. All three wires have continuity to that connector, ground (black) has continuity to chassis, red has +12v on it. All it can be at this point is the rest of harness which would be crazy to replace or PCM. Does anyone have PCM pin out schematic? I’d like to run a new wire for the LIN bus all the way from the source. So frustrating!!!

 

[kapinallinen2]

The damn U11E9 code had me take the entire front grille off (so unnecessarily complicated), replace the AGS motor, replace the pig tail connector to the AGS motor and the code hasn’t disappeared. I ran continuity test from AGS motor plug back to a first major harness connector located behind the front bumper on the driver side. Photo attached. All three wires have continuity to that connector, ground (black) has continuity to chassis, red has +12v on it. All it can be at this point is the rest of harness which would be crazy to replace or PCM. Does anyone have PCM pin out schematic? I’d like to run a new wire for the LIN bus all the way from the source. So frustrating!!!

C1 pin 55, circuit D511, WH/BG, Gauge/size 0.35, function LIN bus.

Couple other things on that same bus could also be taking it down.
Did you disconnect them to eliminate them as a possible cause? Alldata has a proper procedure on how to do this.

 

[Scuba diver 71]

C1 pin 55, circuit D511, WH/BG, Gauge/size 0.35, function LIN bus.
View attachment 182078
Couple other things on that same bus could also be taking it down.
Did you disconnect them to eliminate them as a possible cause? Alldata has a proper procedure on how to do this.
View attachment 182079

Thanks! That is so helpful! I haven’t disconnected anything yet as I did not know that other systems are on the same LIN bus. I will sign up to Alldata and try to get this fixed once and for all. This has been by far the most frustrating issue on my Ram to date and It looks like a fairly common problem. Otherwise except for a bad carrier bearing in the rear end, zero issues at 130k miles.

 

[Darksteel165]

AGS is 100% worthless. Why bother investing more money into fixing it?

 

[Scuba diver 71]

Hi Kapinallinen2, I logged into Alldata (super helpful) and determined that my specific truck (e-torque, limited) only uses that LIN bus to operate AGS unless I’m missing something.
Limited doesn’t have the chin spoiler (air dam) and I don’t have the temperature controlled diff so no three way coolant valve. If I’m not mistaken, the only thing on that LIN bus must be the AGS. I’ll check the continuity and voltage of LIN bus at ECU and try to run a new wire all the way thru. If that doesn’t work, I’m thinking it’s got to be the ECU/PCM. Let me know your thoughts. Thanks.

 

[Scuba diver 71]

AGS is 100% worthless. Why bother investing more money into fixing it?

I’d love to leave it alone except it throws the U11E9 code which illuminates CEL and prevents remote start. Also, with CEL, you can’t pass state emission test. It’s a problem.

 

[Darksteel165]

Hi Kapinallinen2, I logged into Alldata (super helpful) and determined that my specific truck (e-torque, limited) only uses that LIN bus to operate AGS unless I’m missing something. View attachment 182134
Limited doesn’t have the chin spoiler (air dam) and I don’t have the temperature controlled diff so no three way coolant valve. If I’m not mistaken, the only thing on that LIN bus must be the AGS. I’ll check the continuity and voltage of LIN bus at ECU and try to run a new wire all the way thru. If that doesn’t work, I’m thinking it’s got to be the ECU/PCM. Let me know your thoughts. Thanks.

Did you verify you don't have the AAD? My 22 Limited does. It's behind the bumper not attached to it.

I’d love to leave it alone except it throws the U11E9 code which illuminates CEL and prevents remote start. Also, with CEL, you can’t pass state emission test. It’s a problem.

What state do you live in? That's not an emissions code so wouldn't stop me from my yearly inspection. Wonder if you could tinker in Alfaobd to remove the code generation.

 

[Scuba diver 71]

Did you verify you don't have the AAD? My 22 Limited does. It's behind the bumper not attached to it.


What state do you live in? That's not an emissions code so wouldn't stop me from my yearly inspection. Wonder if you could tinker in Alfaobd to remove the code generation.

I’m in Illinois. I positively have no automated chin spoiler on my truck. I’m the first owner so I know it was never there.

 

[kapinallinen2]

Hi Kapinallinen2, I logged into Alldata (super helpful) and determined that my specific truck (e-torque, limited) only uses that LIN bus to operate AGS unless I’m missing something. View attachment 182134
Limited doesn’t have the chin spoiler (air dam) and I don’t have the temperature controlled diff so no three way coolant valve. If I’m not mistaken, the only thing on that LIN bus must be the AGS. I’ll check the continuity and voltage of LIN bus at ECU and try to run a new wire all the way thru. If that doesn’t work, I’m thinking it’s got to be the ECU/PCM. Let me know your thoughts. Thanks.

All I can really comment on is in relation to my 2019 Rebel and what comes up on it at alldata.
According to the schematic, there is upper and lower grill shutter with separate motors.
I would follow the troubleshooting steps listed in alldata for the AGS.

 

[Cbty2050]

Voltage drop or load test the power and ground circuits. What is the min/max v of your lin circuit? When nothing trying to communicate on lin should be 12v on circuit

 

[kapinallinen2]

Anyone have any captures/screen shots of the LIN bus data stream?

 

[Scuba diver 71]

Voltage drop or load test the power and ground circuits. What is the min/max v of your lin circuit? When nothing trying to communicate on lin should be 12v on circuit

Are you saying that voltage on the LIN bus should be around 12V? Some say it should be around 9V. I’ll be checking mine today and will report asap.

 

[Cbty2050]

Are you saying that voltage on the LIN bus should be around 12V? Some say it should be around 9V. I’ll be checking mine today and will report asap.

A non communicating system will be 12v, as the lin bus isn't actively communicating. Attaching a small sample size of lin bus communicating voltages. The voltage will vary from 12v to 1v at a very fast rate, the meter isn't quick enough to actually show it on the screen, a good meter will catch it with the min/max function.

 

[Rick3478]

I would just add that loss of ground connection to any device on the LIN bus will make that device unable to communicate.

 

[Jedi9]

all I can add is my AAD is removed and disconnected and it shows up on a OBD scan but does not cause the CEL to come on.

 

[Scuba diver 71]

A non communicating system will be 12v, as the lin bus isn't actively communicating. Attaching a small sample size of lin bus communicating voltages. The voltage will vary from 12v to 1v at a very fast rate, the meter isn't quick enough to actually show it on the screen, a good meter will catch it with the min/max function.

The LIN bus voltage on my truck varies between 6.3mV (milivolts) with the ignition off to 8mV with the engine running.

 

[kapinallinen2]

The LIN bus voltage on my truck varies between 6.3mV (milivolts) with the ignition off to 8mV with the engine running.

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]

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?