I would suspect low fluid level. If the fluid level is ok, then have the brake system inspected.
How to Reset Maintenance Warning Light on a 2008 Toyota 4Runner
A 1991 Toyota 4runner is bigger than a 1990 4runner
What warning? You could try the handbook or asking at the nearest Toyota dealer.
There is no recall for the Toyota 4runner transmission. Some Toyota's have had break problems that may have started the recall rumors on some Toyota products but, there is no recall for the Toyota 4runner transmission.
The 2014 Toyota 4Runner has a V6 engine.
The 2002 Toyota 4Runner has a V6 engine.
The 2004 Toyota 4Runner has 24 valves.
The 2008 Toyota 4Runner has 24 valves.
The 2007 Toyota 4Runner has a V6 engine.
The 2011 Toyota 4Runner has a V6 engine.
The 2007 Toyota 4Runner has 24 valves.
The 2013 Toyota 4Runner has a V6 engine.