Ascent CAN Flex Fuel

Congratulations on your purchase of the COBB Tuning CAN Flex Fuel! The following instructions will assist you through the installation process. Please read them BEFORE beginning the install to familiarize yourself with the steps and tools needed. If you feel you cannot properly perform this installation, we HIGHLY recommend you take the vehicle to a qualified and experienced automotive technician.

[ 1 Parts List ] [ 1.1 Subaru CAN Flex Fuel Kit ] [ 1.2 346700 Fuel Pressure Sensor Kit ] [ 2 Tools Needed ] [ 2.1 Sockets ] [ 2.1.1 3/8" ] [ 2.2 Hand Tools ] [ 2.3 Wrenches ] [ 3 A Quick Message on Screw-in Connectors ] [ 4 Pre-Assembly ] [ 5 Gateway and Ethanol Sensor Mounting ] [ 6 Factory Gateway Bypass Installation ] [ 6.1 Ascent Dash Disassembly ] [ 6.2 Outback Dash Disassembly ] [ 6.3 What to do After ]

Parts List

Subaru CAN Flex Fuel Kit

346700 Fuel Pressure Sensor Kit

Tools Needed

Sockets

3/8"

3/8" ratchet
3/8" 12" extension
3/8" 6" extension
3/8" 10mm socket
3/8" 12mm socket (if removing intercooler)
3/8" 13mm socket

Hand Tools

Phillips head screwdriver
Flathead screwdriver
2.5mm Allen Key
3mm Allen Key
3/16” Allen Key (for NPT plug on fuel pressure adapter)
7mm Nut Driver
Trim removal tool

Wrenches

7/8” or 22mm Wrench (for fuel pressure sensor)

A Quick Message on Screw-in Connectors

The screw in wiring connectors we use for environmental sealing are specifically keyed to a certain direction to ensure all the pins are in the right spot. When in doubt gently press while slowly rotating the connector until it lines up, then press it in until the threads engage, then tighten the connector down finger tight.

Pre-Assembly

Using 2 of the m6 nuts and a 10mm socket install the gateway on to the two studs on the left side of the bracket.
On the back side of the sensor you can (but don’t need to) remove the backing from the double-sided tape. It’s main function is to cushion the sensor against the bracket rather than hold it in place, so it’s up to you.
Position the sensor with the strap onto the bracket with the wiring connector in the correct direction for your application. Once the orientation is correct, screw it in from the back side using a 2.5mm Allen wrench and the 4mm flat-head screws

Outback Mounting

Ascent Mounting
Install the fuel pressure sensor into the fuel pressure sensor adapter with a small dab of the provided thread sealer. You may want to test fit it on the car to make sure the sensors harness doesn’t get in the way of anything as things are quite tight. You’ll need to use a 3/16” Allen to remove the NPT plug in place, and a 7/8” or 22mm wrench to tighten the sensor down.

Gateway and Ethanol Sensor Mounting

Park your car in a flat level area.
With your car running, remove the fuel pump fuse and leave the car idling until it dies (this may take a while.) This should depressurize the fuel system to minimize the amount of fuel spilled.
Jack your car up and support it properly, you’ll need to get under it for step 16.
Remove Top Mount Intercooler. While not 100% necessary, it will allow make things much faster by allowing better access to the fuel lines. If you’re having a hard time it might be worth the 5-10 minutes to remove and reinstall the intercooler. Check out our intercooler instructions for tips on removing the factory one VB WRX, Ascent, Outback Top Mount Intercooler Removal
On the passenger’s side of the engine bay Locate the fuel line underneath the strange aluminum AC line loop. It should have a black retaining clip over the line.
On the end towards the front of the car, gently spread out the curved legs of the clip, this should release it from the fitting on the fuel line, and then it can be removed from the car.
Using your fingers or a flat bladed screwdriver, pull out the flat center portion of the blue clip to release the soft fuel line. It’s a good idea to have a cloth or absorbant pad there to catch any drips.
Repeat this process at the other end of the fuel line near the intake manifold.
Squeeze the tabs of the fuel line retaining bracket so it can be removed from the car.
Install the two standoffs onto the two studs sticking out from your firewall on the passenger’s side (above where the fuel line comes out) using a 13mm Socket or wrench. These will go over the control module mounted there in place of the nuts holding the module in place.
Plug the ethanol content sensor harness (brown connector) into one of the bottom two Sensor ports on the gateway and loop the harness down and around from the back of the bracket and up onto the ethanol content sensor. The bracket has two vertical slits on the gateway side you can slip a zip tie through to secure the harness.

Ethanol content sensor harness, plugs into either of the bottom two holes.
Install the bracket with the sensor and gateway into the car over the two standoffs, securing it with the two supplied flange nuts. If you have an issue you can install the bracket with the ethanol sensor first, then bolt down the gateway.

Ascent
Take the fuel line with two 90° fittings on it. One end has a smaller opening than the other. The smaller end will go over the factory fuel feed line on the car side, and the larger opening will go to the right side port of the ethanol content sensor. Give each end a gentle tug to make sure they are securely in place. You can then zip tie the hose to the brake lines nearby.
Install the fuel pressure adapter onto the engine side of the fuel line. Then hook the smaller end of the remaining fuel line (straight fitting) onto the adapter pushing it all the way on and latching it closed before giving the whole assembly a gentle tug to make sure it doesn’t come off.
The other large 90° end of the fuel line will go to the left hand port of the ethanol content sensor.

Outback Installation
Plug in the fuel pressure sensor harness and run the wire over to the other unused sensor port on the gateway.

Fuel pressure harness, plugs into either of the bottom two ports.
Plug in the long vehicle harness for the gateway to the top left port of the gateway and screw it down. The harness can get routed behind the two wiring harnesses and down into the engine bay following the brake lines.

Gateway to vehicle harness. Plugs into the top left port.

Route under the other harnesses and down the firewall.
From underneath the car, locate the AC drain hose on the passenger’s side and remove the grommet. This is on the fire wall on the passenger’s side, right next to where the shift linkage is on the transmission.
Push the small connector end up into the hole above the drain line, then slip the hose into the large opening in the grommet on the harness. Then push the grommet into place on the firewall making sure the edges are evenly grabbing the metal. The grommet is deliberately placed on the harness to minimize any water intrusion, do not slide it up or down the harness.

Grommet positioned on adhesive lined heat shrink to provide maximum water intrusion resistance.
Once that’s through, zip tie it out of the way (keep it far away from the CV axle please!)
In the passenger compartment, gently pull back the carpeting in the passenger’s footwell near the center of the car. You should see the wiring coming out. Route it up behind the center console and dash near the stereo.

Factory Gateway Bypass Installation

In order to add signal onto the CAN BUS of the car (and not mess with important functions like brakes or steering) we added components to allow you to integrate into the factory CAN module.

Ascent Dash Disassembly

On the passenger’s side we’ll start by removingthe dash’s end cap. We recommend using a plastic tool do this and minimize scratching. Find a gap and gently pry outward
The upper dash rail will now need to come out, gently pull outward at first until it pops out and you can see the blue clips.
The trim around the screen should now come out, The trim is pretty easy to scratch and has lots of small plastic tabs along the top, covering the trim with blue painters tape before you start and using plastic trim tools should minimize the risk of scratching it. Once you get it started, it pops out fairly easily after that. Pay close attention to the top as it has small built-in tabs going into very small slots.
Now on the center top of the dash there is a speaker grille (that may or may not have a speaker under it). Pull outward to pop it out of place.
Do the same thing with the rear piece of plastic, this should expose the factory gateway.
This should leave you with a giant screen and 4 10mm bolts. Remove those bad boys with a socket and extension and do your best not to drop them. As they come out I like to put my finger over the flange of the bolt to hold it into the socket.
Put a cloth, towel, something soft on the trim right below your head unit, then gently tug the head unit out to gain access to the back side. You shouldn’t need to completely remove the unit, if you need a little more room try just removing the top two wires as those are usually streched the tightest.
With access behind, fish the wiring up from the passenger’s footwell. Using a piece of wire (with the ends capped with tape to prevent scratches) fish the wire through and tape the wire to it before pulling it back up to the top.
Using a Phillips Screwdriver unscrew the gateway module from the dash.
Now go ahead and unplug the factory harness and install the included bypass harness into the connector.
Push the stock gateway harness down under the bar of the dash but above the pillowy substance, then fish the gateway harness through from the top.
Stick one piece of the definitely not velcro because that’s a namebrand product onto the back side of the bypass module. Then push the other half onto that piece but don’t pull the adhesive cover off yet.

Outback Dash Disassembly

Remove the end cap from both sides of the dashboard.
Remove the screw behind the dash cap on the driver’s side, and one on the bottom right ofthe lower panel.
Gently pull outwards to remove the lower panel, you can either let it hang or disconnect the buttons and move it out of your way.
Undo the two screws on the underside of the instrument cluster.
Gently pull outwards on the panel with the vent on the passenger’s side, slowly working it across to the gauge cluster surround. Disconnect the wiring for the button when you get there.
Firmly pull outwards and up on the trim above the stereo, repeating the same with the piece behind it.
Undo the two screws holding the speaker in place and disconnect the harness.
Straight back you’ll see the gateway nestled in between the AC ducts. You shouldn’t need to remove it, just unplug it, this is where you’ll plug in the COBB bypass wiring harness, the stock harness will go into the bypass module.
With access behind, fish the wiring up from the passenger’s footwell. Using a piece of wire (with the ends capped with tape to prevent scratches) fish the wire from the gateway through the dash to where the harness is coming through, and tape the wire to it before pulling it back up to the top.

What to do After

Plug the smaller end of the bypass wiring harness into the bypass module, then zip tie it through the middle hole of the module to hold it down and out of the way.
Now the stock gateway wiring harness can get plugged into the COBB module along with the 4 pin harness coming from the gateway.
With everything plugged in, you can stick the bypass module someonewhere on the underside of the dash with the adhesive side of the velcro.
Everything can now go back together because you’re all done! Make sure to go slow and check to make sure you don’t have anything left unplugged (unless, like our car you had one plug not plugged in to anything from the beginning).
You’re all done! Go out and enjoy!

346625 - Ascent / Outback CAN Flex Fuel