How to Convert a Firestone Air Command F3 Dual-Path System to Single-Path Smartphone Control  

Question:

Expert Reply:

Hey Ben!

I definitely understand why that's frustrating. Yes, you can switch your Firestone Air Command F3 Xtreme Duty from a dual-path system to a single-path system without replacing your entire setup!

You'll need the Replacement ECU Service Pack # F69VV along with the Smartphone Compatibility Wiring Harness # F79VV. This will allow you to control both air bags together at the same pressure using Firestone's smartphone app instead of your old wireless remote.

I found a previous customer who wanted to make this same conversion, and we confirmed with Firestone that these parts would work. You should be able to keep your existing compressor and air tank, although you'll need to modify the air lines to connect both bags to the single-path ECU. Firestone recommended adding a Tee Fitting # F3025-1 and some additional Air Line # F49ZR for that conversion.

As far as the compressor relay and existing wiring go, the new harness will replace some of the original connections, so I wouldn't count on reusing every electrical component.

One thing I do want to mention is that switching to a single-path system won't necessarily prevent an internal air leak from causing unwanted inflation. It will simply mean both bags share the same pressure instead of being controlled independently. Since your current ECU appears to be allowing air into the bags when it shouldn't, replacing it should address that issue as long as the ECU is the source of the problem.

Have you noticed the bags increasing in pressure primarily while the compressor is running, or does it also happen after the compressor has shut off?

expert reply by: Jerry B

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Ben T.

10/14/2026

The air bags increase air pressure with the pickup and compressor shut off. Then when I start it, it will not deflate to my requested pressure because with the remote is inside the cab, it will not communicate with the ECU. I don't understand how the new ECU (F69VV) you suggested will work with an air tank system like I have. If I run the air line from the air tank to the new ECU and also have that same air line with a tee going to the air bags, the air bags will be at the air tank pressure. The compressor needs to fill the air tank to 125PSI and then shut off. From the tank, the ECU needs to inflate the air bags to the desired pressure. I think I would need an ECU with an IN port from the tank and an OUT port to the air bags. F69VV is only a single port ECU. If I am wrong, please send the correct schematic.

Jerry B.

10/14/2026

@BenT You're absolutely right, and I see what you're saying now! My apologies for the confusion. Your air tank needs to maintain its own pressure at 125 PSI, while the ECU controls how much of that air gets sent to the bags. I can see now that putting a tee between the tank and bags like I originally suggested would defeat the whole purpose of having the ECU. I went back and checked the original setup for your 2592, and you're right about needing separate inlet and outlet connections. While Firestone has confirmed the # F69VV can be used to convert certain dual-path systems to single-path, I haven't been able to confirm it'll work with your air tank setup. I don't want to steer you toward something that won't work, so I'd hold off on ordering that ECU until we can get confirmation from Firestone on the tank compatibility. I'll reach out to my rep at Firestone and see what I can find out for you! Sorry again for sending you down the wrong path, but I'll follow up with you soon once I have an answer!