How To Test A Prodigy P3 Controller Without Having Direct Access To The Trailer

Updated 08/05/2025 | Published 09/06/2022

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Question:

Hey I currently got a prodigy p3 to work with my 2013 Volkswagen Touareg TDI with tow package. I have same exact set up in video shown in the how to , very simple set up especially with the video. My question is how can I test the brake controller if possible? without connecting a trailer? I dont have direct access to a trailer with brakes but will be renting an RV with brakes and the P3 turns on when plugged in and I get the menus but obviously shows no trailer. If I put a multimeter on the 7 pin can I check if I hit the brakes or it only works once a full 7 pin trailer is connected? thank you so much

asked by: Anthony S

Expert Reply:

Since your prodigy P3 is a proportional controller you can partially test for function at the trailer connector using the hook probe circuit tester # PTW2993. You can use this tester to test the pin the 5:00 position on your trailer connector while someone else applies the manual trailer braking switch on the P3. You should see signal on the tested when the switch is actuated.

You can also test the red wire exiting the rear of the controller as the brake pedal is being pressed and again you should see a current on the tester when the brake pedal is pressed.

If you have a friend or neighbor that has a trailer with electric brakes you could make 100% sure by hitching up to their trailer.

I attached a review video link below.

expert reply by: Noah E

Tonyr

8/5/2025

Say everything is hooked up correctly but you cut the red wire at the back and send power to the red wire with a power probe. Shouldn't it activate the brakes like you just applied the brakes?

Jameson C.

8/5/2025

@Tonyr It will think the brakes are applied and begin to look for deceleration with it's inertia sensor and apply the brakes in a relative manner. Now since you'd most likely be stopped when doing this test you won't see much voltage unless you have a boost setting turned on.

Tonyr

8/5/2025

@JamesonC Thank you, that is actually what I needed to know.