In Watch Dogs, the city of Chicago is under the constant surveillance by the ctOS monitoring system. This guide will take you to all 13 ctOS Tower locations, and shows you how to hack your way to them so that you can install backdoors onto them. Doing so earns you the Clear Signals trophy/achievement and reveals the locations of all collectibles, side missions, hideouts and fast travel points in Chicago. A powerful advantage for any hacker.
Also check out the the Burner Phone collectible guide.
Before You Begin
The backdoor to the Parker Square ctOS Towers can be installed right away, but you'll have to get through all the ctOS Systems across Chicago before you can get to the rest of them. Unfortunately, these systems aren't accessible until after you complete the Backstage Pass mission. ctOS Systems will appear on your map once that mission is done. Getting through the Systems will reveal the ctOS towers in each district.
Parker Square District - 2 ctOS Towers
ctOS Tower 01
This is located a couple blocks northeast of your hideout. It might prefer to just walk there. Once you've arrived, hack the forklift in the back alley, which opens up access to a catwalk. Follow the catwalk to a blue lift, get onto it and hack it to reach the roof. Climb onto the air conditioners and go up the yellow ladder. Hack into the camera inside the fence and use it to unlock the door. Now go inside and install the back door.
ctOS Tower 02
The second tower can be found north of the first one. It's found atop a hill with a dirt road going to it. Go through the gate upon arrival and head to the back to find a camera high up a wall. Use the camera, lower the forklift to reveal the next camera, then jump to it and unlock the door. Head back to the fence opening, and step through the gate with a yellow ladder next to it. Go up the ladder, then drop down to the ctOS Tower and install the backdoor.
The Loop District - 3 ctOS Towers
ctOS Tower 03
You'll see three new ctOS towers show up on your map after you've taken care of the The Loop's ctOS system. Head to the west-most tower. Once there, go into the alley and hack the camera found high up on a fence. Turn the camera and jump to another camera that's higher up on the wall. Use this camera to unlock the gate, marked by a box beside the front bumper of a billboard car. Now switch to the camera high up on the building with an open garage door. Use it to unlock a gate on the right. Now use the blue lift to get to the roof, then keep climbing to the gates. Go through the gates, make your way over some air conditioners, and finally onto the roof to install the backdoor.
ctOS Tower 04
Go to the point just south of The Loop District. You'll find a blue lift on the ground when you get there, but don't get on it yet. Hack the camera located on the corner of the building and use it to jump to another camera higher up on the other side of the alley. Then hop to a third camera and unlock the gate. Switch to a fourth camera and use it to unlock a panel that needs to be hacked. Once all that is completed, get onto the blue left and take it up. Climb the air conditioners, get over the fence, and you'll reach some stairs. Take them up and get onto the roof from the left of the explosive panel. Go through the gate, make your way left and go over some more air conditioners, and you'll reach the final gate. Through it is the ctOS panel you need for installing the backdoor.
ctOS Tower 05
You'll find this tower on the east end of the island, and it can be accessed from the alley. Once you reach the alley, look up to find a blue lift. Hack it to bring it down, the take it up to the roof. The camera you need is directly across the way, but you can't see it yet. Jump over the railing go get to the lower roof, and you can hack the camera from there. Unlock the door, then return to the roof and go through the gate. Now you can install the backdoor onto the final ctOS tower in The Loop district.
Mad Mile District - 3 ctOS Towers
ctOS Tower 06
Go to the west end of the Mad Mile district and find a courtyard with people hanging around. Hack the panel on the wall behind the iron fence. Now go through the alley and use the blue lift to get up to the balcony. From there, go up the yellow ladder, through the gate, and up a curved glass roof. Turn around when you're on the glass to hack an unlock box on the wall. Then keep moving up the curved roof, up onto some air conditioners, and through another gate. Go right, over a second curved roof, and jump the past the two people doing yoga. This brings you to the ctOS tower, where you can install the backdoor.
ctOS Tower 07
This tower is found on Mad Mile's far west side, on a small island near Parker Square. While on the street, hack the camera behind the black iron fence and then unlock the gate. As you're facing the building, go left and around to the opposite end. You'll walk through an open gate and up two staircases. When you've reached the top, move counter-clockwise around the building until you reach a yellow ladder and climb it. Then hack the unlock box on the wall, walk through the gate, and install the backdoor onto the ctOS tower.
ctOS Tower 08
When you reach the last tower location, hack the parking garage door from the car, then drive up to the third level. There will be a yellow ladder on the wall across the way. Use the ladder, then move counter-clockwise through the building until you can't continue any further. Go over some air conditioners, then keep going counter-clockwise until you reach the unlock panel. Hack it, then head back the way you came to access another panel, which grants you remote access to a server room. Hack the laptop sitting on the desk and use it to unlock the gate using a wall panel. Now use an air conditioner nearby to get up to the ctOS Tower to install the backdoor.
The Wards District - 2 ctOS Towers
ctOS Tower 09
Start on the west end of The Wards. You'll know you're in the right spot when you find yourself under some train tracks and you can see the tower. There's an unlocked gate across the street from the tower, near a forklift. Step through it and go upstairs. Then climb the ladder and go through another gate to find some citizens milling around. Wait for the train to pass by, then go onto the tracks and run to the tower. Hack into the camera on the other side of the fence, then switch to the camera on the left. Tilt the camera down and to the left, then zoom in on the wall panel. Hacking the panel unlocks the gate, allowing you to reach the ctOS Tower and install the backdoor.
ctOS Tower 10
When you reach the second ctOS Tower, go around the building to the blue lift and take it up. Now hack the camera attached to the light pole on the right, then jump over to another one that's higher up and located over your head. Switch to a third camera through a door, then hack the unlock panel. Get up onto the roof, step through the unlocked gate, and then go right to go onto some air conditioners. You should be able to see the unlock panel below you while standing on the air conditioners. Hack it, then start backtracking. Go through the gap in the buildings until you find the yellow ladder at the end of a catwalk. Go up the ladder, then through the gate, and you'll find the ctOS Tower. Installing the backdoor will finish your search trek through The Wards.
Brandon Docks District - 3 ctOS Towers
ctOS Tower 11
Go to the tower located at the southeast side of the Brandon Docks. On arrival, look for a car that's lined up with a shipping container, but don't get into it yet. Instead, go around to the building behind the car and hack the unlock panel. Now get into the car, drive it into the container, and ride it up. Drive through the fence, then go through the gate to climb a yellow ladder. The ctOS Tower as at the top. Install the backdoor and leave.
ctOS Tower 12
Go to the tower on the west side of Brandon Docks. Go around the building to find a camera affixed to the corner of an adjacent building. Hack into it, then use the camera to unlock a get located in the direction you came from. Return the way you came and step through the newly unlocked door. Go through the window, climb over the fence, and then use the lift to go up. Head around the building and go through the gates to reach the ctOS Tower and install the backdoor. Now go back the way you came.
ctOS Tower 13
Go around back to find a camera mounted on one of six connected concrete structures. Hack into the camera, then jump to one that's mounted on the outside of a white building. Swivel the camera right and hack the unlock panel. Return to the first camera to find another camera, this one located inside the white building. Switch to that camera and use it to unlock the door.
Walk over to a nearby lift and take it up. Then go up the yellow ladder. Make your way through the gates until you're inside the white building with the ctOS Tower. Install the final backdoor and you'll earn the Clear Signals trophy/achievement.
Congratulations! You found all the towers and got the Clear Signals trophy/achievement!