IAC Issues Code p1504

[Fireman2531]

2000 ranger 3.0. Throwing code P1504. I have replaced the IACV with 2 separate ones, with no luck. Truck starts up and dies immediately. I took off the IACV and it started and idled way high (obviously). Harness has 12v to it. Am I missing something on installing it? I install with the battery disconnected. The plunger does not move when the ignition is turned on. Any tips would be much appreciated!

 

[Jazzer]

What brand of IAC’s were the ones you bought? Hitachi and Motorcraft are the only recommended brands, as the others use stepper motors and don’t always play nice with our Rangers.

And, as said here frequently, new doesn’t mean tested and working any more, the buyer is the QC.

 

[Fireman2531]

A cheap Amazon one and a Duralast from AutoZone. I was unaware of the brand making a difference. You think using one of those you listed would work?

 

[Jazzer]

If your wiring is correct, yes. If you test it by hooking up the wires before installing it, you could tell for sure. You could probably return it if you have a wiring problem and your original proves good.

 

[Fireman2531]

If your wiring is correct, yes. If you test it by hooking up the wires before installing it, you could tell for sure. You could probably return it if you have a wiring problem and your original proves good.

 

[Jazzer]

Signs Of A Bad Idle Air Control Valve & How To Test It

Your car's idle air control valve helps keep the engine running when your foot is not on the accelerator. Use this guide to understand how it works!

theautomotivedude.com

Could be you’re not getting input from the computer, but test first. Good Luck!

 

[Summers22]

To my knowledge, the Motorcraft IAC is no longer available new, so I ordered a Hitachi from AutoZone.

 

[Jazzer]

If you have a multimeter, you can set it to greater than 20v DC, and ground the black probe.

Key on engine off.

Remove IAC connector and probe its contacts. You should get good voltage on one and none on the other. That connector is the ground that’s switched by the computer.