Where is my trailer brake relay located !!

[Zo6_shawn]

I’ve got the “service trailer brake” notice on the dash. Was told to just swap out the control unit under the dash and that didn’t work. Next was told if that didn’t work it was the relay. So I purchased the relay and can’t find a single article or picture online that will show me where it’s located. I’ve found it for the Silverado but it’s not in the remote area on the Tahoe .. any help would be appreciated. 2013 LTZ Tahoe

 

[swathdiver]

I’ve got the “service trailer brake” notice on the dash. Was told to just swap out the control unit under the dash and that didn’t work. Next was told if that didn’t work it was the relay. So I purchased the relay and can’t find a single article or picture online that will show me where it’s located. I’ve found it for the Silverado but it’s not in the remote area on the Tahoe .. any help would be appreciated. 2013 LTZ Tahoe

Hmm, sounds familiar. Look in front of your gas tank on the bracket perpendicular to the frame. Have to loosen bolts from back side and then slide the SSR out. 4.5 or 5.5 mm if memory serves.

Who told you to shotgun this repair? When you get a message on your DIC, there are internal codes stored as to what went wrong and why. Tech-2 time.

 

[wsteele]

I believe it is always near the FPCM (back by the spare on the pickups, on the bulkhead directly under the drivers seat location on the Yukon/Tahoes/Subs, like Swathdiver said).

 

[Zo6_shawn]

Hmm, sounds familiar. Look in front of your gas tank on the bracket perpendicular to the frame. Have to loosen bolts from back side and then slide the SSR out. 4.5 or 5.5 mm if memory serves.

Who told you to shotgun this repair? When you get a message on your DIC, there are internal codes stored as to what went wrong and why. Tech-2 time.

I have an OBD-II , no codes during scan. I was expecting a C code but nothing.

 

[swathdiver]

I have an OBD-II , no codes during scan. I was expecting a C code but nothing.

Depends on the type of code reader. Most can only access the ECM and nothing else.

 

[Geotrash]

I have an OBD-II , no codes during scan. I was expecting a C code but nothing.

+1 to what @swathdiver said. You need a code reader that can read all of the modules in the truck. The regular readers can only read the ECM, and will only show those codes that are required to be available via OBD2 per federal law. Everything else requires a reader that's specialized for GM vehicles. I have a Tech2, as many here do, which is the same unit the dealers use. You can buy them for less than $400 at chinacardiags.com. I also have a unit from iCarsoft that can read all of the modules but not do things like program keys, which is a great solution if you can't spring for the Tech2.