4low & Traction control lights on or stuck in 4 low

[Trollhole]

My fixes for these two symptoms on vehicles in the shop.

4low blinking and traction lights blinking is usually from a gas cap not being on tight or a leak in the evap system. 9-10 it's the gas cap. We have only replaced one cap.

Stuck in 4low on lx570's only. I have found the actual switch on the dash gets something gooey spilled on it and the pins inside that do the actual pushing of the buttons get stuck. Then no matter where you put the switch it will never switch out of 4low unless the interior gets hot enough to loosen the stuck pin. But it will happen again if someone hits that poorly placed switch. You can easily take the assembly apart and clean the pins and most likely the board. I lubricate the small pins with a tiny bit of white lithium grease and everything is fixed. Techstream will tell you if it's the switch because you can view the data on the switch engaging and disengaging. If it isn't then this is usually the problem. I have yet to see this but it could also cause the sport/comfort switch to get stuck as well.

 

[ApexRex]

I've had the 4lo, traction, and engine lights come on 3 times in the past few months, none of them around the time that I had filled up with gas. The codes I got were:

P2446
C1201
C1268
B1421
B1424

I set up the software to clear these codes and then tried to put the truck in low range, where it immediately gave me a fault. Disconnecting the battery for 30 minutes and reconnecting made all of the lights go away and low range usable again. My truck came with the Hewitt Technologies Secondary Air Bypass already installed by the previous owner, so I don't know if that unit is having issues and it's just related, or that is a separate issue entirely.

I've checked all the usual suspects for water intrusion but can't find any actual source, though the large plugs for the body harness at the base of both of my doors had some corrosion in them, I cleaned those but still had all the previously referenced lights come back once afterwards.

I'm going to be replacing the gas cap. Most of the plastics on this truck have been in the Florida and Texas sun for most of it's life (now in VA) so maybe the gasket is failing on the cap. I'm just going to replace it and monitor. Thank you for your post.

 

[tbisaacs]

The finger on the 4low switch can also break off—it happened to me at LCDC last year.

LCDC 2022 retrospective from a first-timer

I'm almost home from my first LCDC and wanted to write down a few things before I forget—and mainly to forget how crummy this hotel room is in Twin Falls. Gratitude First and foremost, thank you to @codyaustin5, @indycole and the cast behind the scenes, and Dissent, Slee, @Eric Sarjeant and...

forum.ih8mud.com

 

[TheComedian]

Other options are a broken ABS cable or a (I know in the US not that often) broken OEM rear diff lock actuator.