Troubleshooting Error Code 4 of Curt RVI Series 4 Supplemental Braking System

Updated 05/27/2026 | Published 01/26/2026

Question:

New RVI 4 gives error code 4 when trying to set up for the first time

asked by: Walter K

Expert Reply:

Hey Walter, I checked with Curt and the RVI Series 4 part # RVI44FR that you referenced showing a Code 4 is related to exposure to cold weather and it's causing some circuit board issues. The solution is to let it sit indoors to warm up for 15 to 20 minutes and it will work again. With as cold as it's been here I believe this to be what's going on! Try that and let me know if you still have issues.

expert reply by: Jameson C

Walter K.

1/29/2026

Located in Arizona, night temps 40 degrees, day temps 70 degrees. Bringing the unit inside did not resolve the error. Talked to Collin @ Curt product support 1/27/26. Troubleshoot & no resolution. Gave me a case #6520556? Now waiting for something to happen, I guess. I Emailed Curt product support on 1/28/26 to receive updated status information and still waiting for a response.

Jameson C.

1/29/2026

@WalterK Interesting! Yeah I wouldn't think it's a weather problem at all then. They can take a little longer with that type of thing so I know it's frustrating but I would be patient and I'm sure they'll help. Otherwise let us know and we can try and push it along.

Walt

2/2/2026

@JamesonC A week and no response, maybe you would help, we have a trip planned and did not expect an issue with this RVI 4 system Thanks for any assistance you can provide. As a longtime E Trailer customer I hope you can assist

Jameson C.

2/2/2026

@Walt I emailed them just now and will let you know what they say!

See All (5) Replies to Walter K. ∨

Ginger

5/27/2026

I’m getting this code also and I live in FL. It has not been cold for months. Please help me figure this out!

Jameson C.

5/27/2026

@Ginger I checked with RVI and if the error persists after warming the unit, a soft reset (disconnecting the power for 60 seconds) or a hard reset (disconnecting the towed vehicle's battery cables and holding the terminals together) is recommended.