I just returned from deployment and my wife's 2009 MCS has been acting up for the last few months. She actually decided to stop driving it until I got home! So I've spent the last two days trying to figure out what might be wrong. Here's the gist:

No cautions are set upon start up. The yellow brake and DSC light come on as I'm backing out of the driveway. Turn signals don't auto cancel while driving, either. Cautions seem to go away on shut down / restart.

When I first started troubleshooting I had quite a few other cautions. They included the "service mini" symbol and the brake pad wear indicator. The front pads are in need of replacement so that's on tap in the coming days/week. To further my troubleshooting I pulled the brake pad sensor and spliced the wires together to try and clear the caution. I also pulled up the menu where I can reset the service intervals and reset each interval.

Is there another step to reset the brake pad sensor? Could that still be causing the problem?

Is there a way to read the codes that are setting the Brake and DSC light? My OBDII Pocket Scan didn't find any codes. I have NCSExpert but haven't used it for a while. If it can pull the codes that would be great.

My fear is that something might be wrong with the steering angle sensor / SZL. I replaced the SZL a little over a year ago. I purchased a used SZL off a different car to enable a multi-function steering wheel I wanted to install. I reprogrammed the SZL in NCS Expert and had everything working great for about a year. Perhaps I need to reprogram again? Can the car "forget" its coding? It has not been to a dealer but the battery has died at least once.

Thanks so much for any help!

 

It sounds like you are further into the electrical system than I ever got. Start with the basics: Has the battery been replaced? I've read that some wierd stuff happens when the battery is on its way out.

Did you confirm that the brake warning is on the front? I also spliced and reset in the past and I think that there was some issue on my end also.

Nothing like a series of projects for 'welcome home'. Glad you made it back safe.....

Have fun,
Mike

 

I was never able to determine if it was the front or rear pad sensor so I spliced both.

​​​​​​​The battery is pretty healthy but I'll keep that in mind.[/left]

 

Update...

I still have been unable to pull the code setting this DSC caution. BUT I confirmed, it is not on during startup and only pops once I exceed about 40 degrees of turn with the steering wheel. Thoughts?

I double checked the coding for my MFSW / SZL that I installed previously and everything is still correct. I may put in an old SZL to see if that fixes the problem...

 

you should be able to tell if you scroll down through the menu and go to "service". it will tell you how many miles are left on the brakes or how many miles you are past due. I tried the splicing thing and it did not work for me. also, check the fluids.

 

The error ended up being related to the steering angle sensor after all. The turn signals not auto canceling was the dead give away.

I did a number of things to troubleshoot. Ultimately disconnecting the battery and removing / reinstalling the SZL removed the error. The battery alone may have been enough to reset the system. I actually installed a different SZL, the cautions were removed, and then I reinstalled the original SZL and the cautions stayed out.

We'll see how long this lasts. I'll report back if I have any further issues.

 

Just came across this thread. Glad to hear you figured it out and thanks for sharing here. Let us know in the future if you have any questions!

Drive Hard. Drive Safe. Keep Grinning.