Troubleshooting Brake Controller with OL Code when Brakes are Applied

Question

Question:

When applying controller signals OL

asked by: Frederick L

0

Expert Reply:

If you check out the attached instructions for the Curt TriFlex Trailer Brake Controller # C24VV you can see that the OL code you are getting means that there is an "Overloaded output circuit, trailer brake system fault".

Whichever controller you have the problem and solution is the same. You have a short on your brake signal circuit from your brake controller to your trailer brakes which is causing too much power draw.

Check both the tow vehicle and trailer connectors and make sure they are clean and free of corrosion and debris. If they look good move on to the actual wiring and grounds for the brake circuit and your brake magnets. Make sure the wiring is undamaged and your grounds are securely connected to a clean, bare-metal surface. When you fix this it will fix your code.

expert reply by: Jon G

0

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Dave P.

4/27/2024

I get OL signal without a trailer hooked up. Any comments?

Jon G.

4/29/2024

@DaveP It means you have a short on that blue output wire from the brake controller and it could exist all the way back to the 7-Way pin on your vehicle. Trace that wire and look at all of the connections and pins for that circuit - be sure to fix anything that looks out of place.

Scott

4/28/2025

@JonG We were towing down a mountain and I was applying manual trailer brake input with this unit, when all of a sudden it said OL and has ever since. Even without the trailer attached. Why would it be working (for over a year) then suddenly do that? What all should I check?

Jon G.

4/28/2025

@Scott You'll want to trace the wire I referenced above.

Answer 1

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Answer 2

The troubleshooting guide included in the instructions for the Curt Discovery Brake Controller #C84VV that you referenced does not include this particular display issue, a flashing 0.0, among the possible display messages. My technical contact at…

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Answer 3

On your Curt TriFlex Trailer Brake Controller #C24VV, the decimal point as you put it is standby mode with no trailer connected. The blank screen is also standby mode and that screen is what is seen when simply starting the vehicle, but that screen…

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Answer 4

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Answer 5

Unfortunately the Atwood 85736 cannot be replaced so you'd actually need an entirely new actuator. The closest replacement we have is the Demco Hydraulic Brake Actuator #DM72VR. This actuator has a gross towing weight capacity of 7,000-lbs, a…

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Answer 6

Hi Randy! We haven't done an install on a 2025 Ram1500 yet, but it looks like the plug you want is either to the right of the steering wheel or just to the right of the emergency brake (I couldn't find a definitive answer saying which spot).…

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Answer 7

Hey Richard! I would expect to have to take your 2025 Ram 1500 to the dealer to reprogram your ECM for the brake controller to work. We don't have any specific reports one way or another that I'm aware of but, if it is required for the OEM…

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Answer 8

I'm assuming you have a tandem axle trailer and therefore 4 wheels. The highest rated tires we carry for 15 inch rims is load range E with a capacity of 2,830 pounds. Multiplied by 4 that's 11,320 pounds which is a good amount for your 12,000…

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Answer 9

We can get you everything you need for towing with your 2017 Toyota Sienna XLE. By plastic shield, I believe you are referring to the appearance panel underneath the Sienna, and that will have to trimmed a bit in each of the hitches available for the…

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Answer 10

The Curt Assure Trailer Brake Controller with Dynamic Screen item #C49UR, you were looking at, would be a great brake controller for your 2006 Dodge Ram 2500. It is a proportional brake controller designed for use with electric or…

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Answer 11

Without knowing what brake controller you have I will venture to guess that the OL code you are seeing is an over load code. The OL or overload error code indicates a short in the brake output circuit. Start by examining the trailer connector. Make…

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Answer 12

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Troubleshooting Brake Controller with OL Code when Brakes are Applied

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