Which wires give constant, ignition and ground on a 2015 Cadillac XTS?
On a 2015 Cadillac XTS, take constant power from the Red/White wire at the blue 27-pin plug on the BCM, left of the steering column, pin 1, ignition from the Purple/Black wire at the green 25-pin plug on the BCM, and ground to clean, bare body metal. Meter every wire first.
Meter every wire before you tap it. Colors change with trim and build date.
OBD-II port:Under the dash, driver sideBest power spot:BCM plugsSystem voltage:12VIgnition type:Push to start (this page)
Where do I get constant, ignition and ground on a 2015 Cadillac XTS?
Constant and ignition are on the BCM plugs left of the steering column.
Option 1 Main option
BCM plugs
Blue 27-pin and green 25-pin plugs on the BCM.
Constant
Red/White
Blue 27-pin plug on the BCM, left of the steering column, pin 112V battery feed. Fortin fuses it at 5 amps.
Ignition
Purple/Black
Green 25-pin plug on the BCMIgnition. Meter it first.
Accessory
Fuse tap
Not in the guideNo accessory wire is listed. Use a fuse tap.
Ground
Body ground
Bare metal under the dashNo ground wire in the guide. Never the battery negative post.
Pin 17 Lt.Blue is the start/stop button signal and pin 22 Lt.Green is CAN data. Never tap them.
Option 2 Accessory
Fuse tap
For an accessory feed.
Accessory
Fuse tap
Interior fuse panelNo accessory wire in the guide. Find a slot hot in accessory and run.
Use an add-a-fuse.
From Fortin's install guide for the 2013 to 2019 XTS with push to start (guide 95331).
Where are the turn signal, reverse and light wires on a 2015 Cadillac XTS for advanced 360 multicam and video telematics installs?
Circuit
Wire color
Location and what it does
Left turnNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Right turnNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Park lightNegative -Not yet checked
Lt.Green/Grey
White 26-pin plug on the BCMNegative parking light. Meter it first.
HeadlightNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
ReverseNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Dome lightNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Each chip shows the main insulation color with its stripe. Source: Fortin's install guide for the 2013 to 2019 XTS with push to start (guide 95331).
Where are the brake, door, speed and CAN wires on a 2015 Cadillac XTS for advanced 360 multicam and video telematics installs?
Circuit
Wire color
Location and what it does
BrakePositive +Not yet checked
Dk.Blue/Yellow
Blue 27-pin plug on the BCM, left of the steering column, pin 7Positive with the pedal down.
CAN dataDataNot yet checked
Lt.Green (single wire CAN)
Blue 27-pin plug on the BCM, left of the steering column, pin 22Data only. Never cut it or use it for power.
DoorsNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Parking brakeNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Vehicle speedNot foundNot yet checked
Not found
Not foundWe found no source for this wire.
Source: Fortin's install guide for the 2013 to 2019 XTS with push to start (guide 95331). Wires marked Not found were not in the guide.
Where are the fuse boxes and ground points on a 2015 Cadillac XTS?
Left of the columnBCM plugsConstant, ignition, brake.
Interior fuse panelFuse tapAccessory feed.
Ground pointsBare body metalNever the battery negative post.
Locations from Fortin's install guide.
Where is the OBD-II port on a 2015 Cadillac XTS?
OBD II
Diagnostic portOBD-II port: under the dash, driver sidePlug-in GPS trackers and OBD harnesses connect here. Check the port before you plan the install.
Which years share wiring with the 2015 Cadillac XTS?
Livery and limo buildsSame BCMCoach-built cars keep the factory BCM. Meter before you tap.
★
Help build this pageWant to be famous?Share a wire color, a photo or a tip for this vehicle, and your name goes on this page.
Add yoursClose▾
This page covers the 2015 Cadillac XTS sedan with push to start.
The wire colors come from Fortin's install guide, read wire by wire. Our own team has not yet metered these on a 2015 XTS.
Written by API Signal, fleet GPS and camera installers for 35+ years across Georgia, South Carolina and North Carolina, installing every major telematics and camera brand. Every wire on this page lists its source.
Test every wire with a meter before you tap it
No wiring information is ever guaranteed. Colors and locations change with trim, options and build date, and the manufacturer can change them in the middle of a model year. We share this as a starting point for installers, and you are responsible for confirming every connection on the vehicle in front of you.
Common questions about 2015 Cadillac XTS wiring
What wire is constant power on a 2015 Cadillac XTS?
Red/White at the blue 27-pin plug on the BCM, left of the steering column, pin 1. 12V battery feed. Meter it before you tap it.
What wire is ignition on a 2015 Cadillac XTS?
Purple/Black at the green 25-pin plug on the BCM. Ignition. Meter it before you tap it.
Where is the brake wire on a 2015 Cadillac XTS?
Dk.Blue/Yellow (positive +) at the blue 27-pin plug on the BCM, left of the steering column, pin 7. Positive with the pedal down. Meter it before you tap it.
Which years share wiring with the 2015 Cadillac XTS?
2013, 2014, 2016, 2017, 2018, 2019. Fortin uses the same guide for every XTS year.
Help build this page
Had the panels off on one of these? Show the next installer what you found.
No one has sent photos for the 2015 Cadillac XTS yet, so yours could be the first. Every photo, wire color and tip we use goes on this page with your name on it, and it saves the next installer time under the dash.
1. Snap it
The plugs, tap points, fuse boxes and ground points. Phone photos are fine.
2. Send it
Tap "Add yours" at the top of this page. Your tip and your photos go in the same box.
3. See your name on it
We check every tip, then post it here "Compliments of" you, by name.
Compliments of
The installers who helped build this page.
★
Founding contributor spot: openThe first installer to confirm a wire or send photos for the 2015 Cadillac XTS gets their name here, and it stays here.
★
Every tip we use gets a creditThe wire you checked is marked "Checked on a vehicle, compliments of" you.
Want to be famous?
Your name, right on this page, for everyone who uses it to see. Add your tip and your photos in one box.
