Service Suspension System message with a code "C0575-1A - Left Front Shock Absorber Actuator Circuit?

Hello,

With the car on level ground can you measure both sides of the front fenders in the same spots to see if there is an off-level issue? If one side is lower than the other side, you will get this code. Do you still have the original struts? I would try reinstalling them to see if that makes the code go away because aftermarket parts sometimes can be a little off. The code is not a circuit error, so I don't think it is the wiring. Through the CAN the yaw sensor can tell if the vehicle is leaning to one side for too long. It actually could be the right-side spring/strut causing the problem. Please let me know.

Thanks for the response. The fenders measure even with each other at 35 7/16" and the DIC shows all level. I thought that since this is not an error with the ride height sensor that it would be electrical, but I don't know. This is the second set of shocks I've installed, and this error came up on the LF on both sets. It did not have this error with the old ones. They were just leaking which is why I replaced them.

I just swapped the left and right shocks (again both new, second set) and I got the same error on the left. Does this mean my module is bad?

It sounds like it, I am wondering if the first left replacement strut shorted out the module or you have a bad connection at the strut or module. Here is the location which is on top of the spare tire so you can check it out. It looks like the suspension module needs to be programmed so I would search google or eBay to look for a preprogrammed unit. Please check out the instructions and location below.

Thanks, I wasn't aware that these could be pre-programmed off the vehicle.

Please let me know if that fixes it. I am interested to see if the strut shorted out the controller.

Will do. I got a new module ordered.

I am always interested because this is a strange problem. Let me know please.

To add to the strangeness, today it’s much warmer here in Texas than it has been since I started having this issue. 30s-60s over the last few weeks. Today it’s in the 80s. I’ve been driving all day and no error messages.

Yep, that is a good one, maybe you just needed to drive it so the system could relearn. Let me know if the code comes back.

It still doesn’t feel like the active dampening is operating. I know because right after I replaced the shocks it rode like a Cadillac. No code now but still a rough ride. Could the module be malfunctioning but not cause an error code? I’m going to replace the module anyway since I’ve already ordered it. Just more confused now than before.

Yes, it could be the module is not working correctly, Can I ask how much the module was? Also please check the fuses to make sure they are okay here is the wiring diagrams so you can see how it work and which fuses to check.

The error message is back ("C0575-1A - Left Front Shock Absorber Actuator Circuit - Performance - Bias Level Out of Range"). I paid $80 for the module on eBay. It was listed as a "new take off. Came of the production line reject for a surface cosmetic blemishes"

I hope it works. Seller has a 30 return policy. Going to have the dealer program it tomorrow.

Nice, yep this should be interesting to see what happens, also double check the connector to make sure a pin has not pulled out and is not connecting. I don't think the wiring when bad by changing the shock out. Please let me know.

Dealer was unable to program so I’ve ordered a new one from GM. Pretty sure the shocks are ok since this is now the third one on that side that’s giving me the same error. The only thing I think might have caused this was I was messing around with the actuation function on my scan tool trying to actuate the shocks and it was taking a while to respond. Thinking it froze up I pulled the plug from the OBDII port. If it was in the middle of sending a command to the module, could I have damaged it? I’m not a mechanic but I’m not a novice. This is the first time I’ve used a bidirectional scan tool. Probably messing around where I shouldn’t have been.

Quick question. Can I drive the car to the dealer with the new module installed before it’s programmed? I’d like to avoid paying another hour of labor to have them swap the modules. It’s easily accessible and I can do it myself. But I don’t want to risk bricking another one by driving to the dealership without the software.

You should be okay but to be sure you can call them to see. Can I ask what brand of shocks are they?

A company called Luft-meister

https://luft-meister.com/collections/shock-absorber?https://www.luft-meister.com&gclid=CjwKCAiAxvGfBhB-EiwAMPakqpgGubdcxecZykJsekEeEZPZbd0hndjfrz8iho58JWjRI1OAZ93RiBoCcmAQAvD_BwE

A company called Luft-meister

Non-OEM, which might have caused the problem. Did you try reinstalling the old struts?

No, I tossed them before I realized I had a problem. This didn't happen right away. Maybe a day or two after install. But the rears are the same brand. No issues. No issues on the front right. I had them send me a second set and even swapped the right and left struts. So essentially, I've put 3 different struts on the left front, all the same brand-new aftermarket ones and I get the same error, only on the left front. That's what got me going down the module path.

Yep, that is the way we must go. Let me know what happens, the module should fix it.

Hey guys, I'd love to hear how this works out. I put the same struts on a 2016 Suburban with ~120k miles on it about 18 months ago. It rode super-smooth, but somewhere along the line, I've noticed that it doesn't ride as smooth. Couple that with the Service Suspension message that has come up about one every 20 key cycles (even before I replaced the struts), and I asked a service guy to look up the codes since I had it in for an alignment. He told me that I had codes C0575-Shock Actuator Level out of Range and C0580. It was a small shop, and they weren't trained to do the work, but they mentioned that replacing the controller and replacing the rear shocks were the only remedies. I'll probably head to the dealer if I have some time, but searching out those codes led me to this thread, which seems like it might be similar in that mine was riding really, really nice and stopped somewhere along the way.

Interesting, I hope the user comes back to tell us what happened.

Well, I did replace the module and it seemed to work, for a little while. The code didn’t come back for the left front but after about a week after replacing the module I got the same error (bias level out of range) for the two rears. It only came on once but that convinced me that the shocks are the culprit. I think they are designed to work with our suspension systems and have all the same components (magnetic fluid, actuators) as the OEM. But at less than half the cost, corners must have been cut. I think it may just be a quality issue. I decided at that point that these shocks just weren’t going to be a long-term fix and that they had been the problem the whole time. I installed a full set of GM shocks and (fingers crossed) have not experienced any issues. I’ll be honest, the GM shocks didn’t ride as smooth as I expected at first. But now that I’ve put a couple hundred miles on them, they feel much better. So, the lesson learned for me was I should have just gone with the GM shocks from the start. You save almost $1,000.00 with the aftermarket but I’ve been chasing issues for over a month and ended up buying a new module that I probably didn’t need. I’m going to swap the modules back just to see if it still works now that I’ve sorted out the shocks.

Thanks for getting back to us, more and more aftermarket parts do not work with today's cars it seems like, I will keep this is mind and share this post in our expert forum to alert them. Sorry for the hassle you went through.

Quick follow up. The shocks are working great without any errors. However, I did notice a little "clunkiness" when driving over speed bumps or while driving slow on bumpy surfaces. With the new shocks I did happen to measure before and after and noticed that the ride height was about a 1/2" higher than before. So, I went ahead and recalibrated the trim sensors using my scan tool and it essentially took the slack out of the trim height sensors due to it riding slightly higher. Tightened it all back up and now it's riding as smooth as ever.

That is good to hear, I featured this post in our expert forum and had many comments. Aftermarket parts are sometimes difficult especially when it involves computer systems. Thanks for letting us know, we are here to help, please use 2CarPros anytime.