you wont need running boards at 5'8"

We are the original owners of a 2014 Toyota Limited 4 Runner 4WD which is equipped with automatic running boards. One year after having the 4 Runner we noticed intermittently the driver’s side running board would either not deploy when the door was open or not retract when the door was closed. The problem began to affect the passenger side running board as well. We brought it up during the routine service appointments at our local Toyota dealership.

I have been a mechanic for over 30 years and am well aware of the phenomena that everything works on the vehicle when the mechanic looks at the vehicle. Of course, the Toyota dealership could not find anything wrong. This continued for almost 3 years until 2018 when I turned in our 4 Runner for service and opened the driver’s door and the running board did not deploy. The dealership tested troubleshot the entire running board electrical system and found an open circuit in the Auto Step Controller Computer assembly (part #: 89720-35011; $339.90). Apparently, this Auto Step Controller Computer assembly has been used on 2012-2017 4 Runners. Beware and watch for the signs of failure listed throughout this post.

We have only had our 4 Runner back for a few hours but the running boards seem to be working fine. I made sure our Toyota dealership was aware that we had reported the automatic running board issues while still under factory warranty & any repairs should be covered. Toyota covered all repairs for the replacement of the Auto Step Computer Controller assembly.

The part comes with a 1 year warranty on parts & labor. I will be watching the running boards to make sure they do not start exhibiting the same failure characteristics as before.

I hope this helps somebody else with their Toyota 4 Runner automatic running board issues.

Yes, I regret the auto-running boards. The fear that everyone has, they are beginning to be very inconsistent. It took about 5 years and 70k miles.

Are they still working, out of waranty and hesitant to take it in for repair.

just had this issue on my 5th GEN 2016 T4R LTD ... auto-running board problem ... first the driver-side started acting up ... it would extend no problem, but wouldn't retract until i hit 5mph or so ... several months later, the passengers side starting exhibiting the same problem ...

took it to my dealer here in colorado ... nearly broadway/littleton blvd ... at first they wanted to replace both motors (first, they were both working - kindof, 2nd, odd that they both go out at/near the same time) ... anyway, they got the motors in (under warranty), replaced them ... same problem ...

their tech got on the horn with toyota's tech ... turns out to be defective ECU (controlling the running boards) ... motors were fine (which makes more sense) ...

they put the ECU's on order ... i'll update more after the parts arrive ...

btw, both motors if replaced after warranty ... $1602 per side ...

Yes there is a TSB for this issue. You can replace the controller yourself pretty easily and it can be found online for 225+shipping and is very easy to do yourself. I just did it this weekend after much frustration with my running boards.

Computer Assembly Side - Toyota (89720-35011) | Toyota Parts

Has anyone been successful in removing them and just putting in a fixed option? Is this difficult to do?

I have had intermittent issues with our automatic running boards not retracting. If i were to push on the boards with my foot, then close the door, they would work so it seemed like resistance was causing the safety feature to engage and the won't retract. Once i started driving, they would retract.

I removed the running boards from the moving support (4 allen bolts on each board) and left the brackets attached to the truck and lubricated everything that moves. Things were not moving freely before lubricating.

When i reassembled, i did not tighten the boards completely down until they were in the retracted position. I had issues with it not working when i tightened things down in the open position. Please be sure to turn off the boards before going under the truck with the boards retracted.

So for me, seems to be a lubrication issue.
I did buy a new running board control unit thinking that was the issue but have not installed. The boards have been working without issue for 3 months now.

Best of luck to all with issues!

You can get fixed running boards, the old ones just un bolt. The only issue is the rocker panels. Get ones that are compatible with limited or modify rockers. There are threads here with resolutions.

I'll give you $100 for that new ECU

Does this happen with the car off? If the car is being started when the running board deploys or stores, this will cause it to fail to deploy or store, as the car starting is taking most of the available power. If storing fails once you start to drive the board will retract at 5mph as a safety feature. If you avoid starting the car right when someone opens a door or within 3 seconds of a door closing this may solve your issue. I don't think they make this clear to owners in the documentation and likely why the dealer can't recreate the issue.

No it does not happen with the car off?

Then I'm willing to bet if you avoid starting the car when someone is opening a door or within 3 seconds of them getting out that you won't have the issue anymore.

just a follow up on my ECU replacement ... working perfectly after ECU (not motors) replacement. i suspect (with no evidence) the ECU's are failing because of where they are mounted (underneath the 4runner, near the running boards) ... perhaps they're exposed to weather/conditions where they don't hold up based on location?

The running board ECU is actually in the driver's side footwell behind the fusebox inside the car. It also has a pretty interesting coating over the chips inside the box that appear to make it somewhat waterproof. I didn't closely compare the two to see what the difference is in chips.

thank you ... i stand corrected