Service Trailer Brake System message

davester · March 7, 2020

Oodles, have you considered having your battery load-tested? Or taking it to the dealer to fix it under warranty?

Tsmooth · June 21, 2021

Similar problem as Ooddels. 2015 Silverado 1500 HC. Troubles starting and seems like the battery is dying often. The DIC throws "Battery Saver Active" and "Service Trailer Brake System". Have had the battery tested recently and they seemed to think that the battery and alternator were good. Ran OBD tester and no codes were given. Currently pulling my hair out. Does anyone have a solution?

GM The one · June 25, 2021

My situation is like yours. Battery was dead this morning and I boosted vehicle. I Ran truck for about 10 minutes. Shut it off and it restarted but I could tell it was ragging a little bit. Drove 200 km. Shut truck off for about two hours. Turned key and it barely started. It was then that the "service trailer brake system" warning showed up. Turned truck off to see if it would reset. Turned key on and it barely started. Drove about 20 minutes. Shut truck off and tried to restart about 10 minutes later and battery completely dead. Dismissed the warning.

Drove home 200km and checked voltage for the last two hours to see if there was a drain. No drain evident on battery. Started truck after 2 hours and started no problem what so ever. Also noticed that the "service trailer brake system" warning did not appear when truck started at this point.

I have read the module can be problematic but you are the only one I have seen with battery related issue. I would normally suspect a short in the wiring system somewhere but have to wonder if it is the module by the rear tire. It could be shorting at that location.

Did you solve your problem?

15GMCALLTERRIAN · December 29, 2021

On 3/7/2020 at 9:08 AM, Oodles said:

Yes!!!!-----I am copying my problem from "2016 Suburban battery drain forum"---nothing going on in that forum (just me and another person with a battery issue)

(By the way---have NEVER towed with my 2017 Chevy Suburban Premier)---here is what's going on---any help would be appreciated)

Have 2017 Chevy Suburban Premier - just over 1400 miles; wife's car; battery went dead yet had it on a battery tender regularly since she doesn't drive it much & would crank it up every now & then to keep battery up & just run things.   DIC was first showing service battery/charging system; then DIC started reading check trailer brake system (mind you, two separate DIC readings now---first it was the charging system, then the trlr brake system). Checked fuses, alternator, trailer brake module inside car----- put in new battery---seemed like that was it. Dead again. Removed trailer brake module inside car, (there are two---one underneath car in back where spare tire is & one inside car driver side dash. Trying to keep it simple, removed only the Trlr brake system module inside car driver side---seemed a bit loose. Plugged it back in. Everything was absolutely perfect!!! No DIC readings, car started right up, & everything appeared to function perfectly. (Note: When we would restart the car at different intervals of trying to source the problem, the DIC would also read "roll driver window, passenger window up and down"! Crazy!!) Everything started right up, all normal indicators. Soooo-----

After a couple days sitting (yesterday) I tried starting car with keyfob---started fine. Later on in afternoon, wife went to start up with push button igition inside car, sounded low on startup. Oh, oh.  She didn't drive but sat in car trying to identify DIC readings, there were none except a DIC reading popped up after she closed & locked the door, so she couldn't read the DIC. Went out this morning to trying to start---deader than a doornail.

Bought service manual books because warranty will eventually run out & service dealer has exemplified extremely poor servicing of my local 2018 Chevy Silverado HD3500 Truck ----made me sit 2-3 hours while waiting for a scheduled apptmt to fix truck, then tell me they have to order part & will call when available---has been over a month & they have not called yet---they have never left a message. Have had service on truck when traveling at dealers out of state, & they have been wonderful. (Two issues on truck have a sensor & another computer-related.)

Something is definitely drawing on the battery, so some special notes for you:

-The radio kept coming on when we would start the car; yesterday wife shut it off completely (still learning about how to use features since she doesn't drive much) so we will see if it comes on again after shutting off (assuming I can get the car running again)---did have Sirius Satellite on promotion of vehicle---it just expired a month or two ago; read one guy went through 4 batteries; read another guy was charged $1200 & had same problem after leaving shop;

-Have On Star capability, but do not subscribe to it. Read one guy found that the drain was the On Star feature;

-Haven't checked my rear trlr module yet.

-Also read somewhere yesterday that you can reset the computer system back to the original defaults---haven't tried yet. Have to find that info again, get the car going again, & may try that first.

-Also read somewhere that it can take a couple of hours for computer system "things" to shutdown after car turnoff---

-I do have a slight spark when I reconnect battery. (You do have to "fake" the hood closed when starting it when hood up.)

Haven't been able to drive car for at least 3 weeks.

After 7:00am this am restart try, dead battery again, recharged battery, reconnected--(still arcing). Now 10:30am today, restarted car via push button ignition inside car (not keyfob start), everything seems ok---still got DIC msg to roll driver/passenger window down & up on initial startup. A few minutes later after full shutoff & door locking, restarted it a second time via inside care press button ignition (not keyfob start) ---did NOT get the "window up & down message". Now letting car sit to see how it drains off again & going back to researching problem.

Status as of March 7, 2020: Battery is now out of car so doesn't ruin new battery. Also, last checked when battery in, not getting any codes on an OBD II Reader----any guidance would be great!!!