What does hot oil light mean when 4 wheel drive is engaged on jeep wrangler?

A hot oil light in a Jeep Wrangler, regardless of whether 4WD is engaged, indicates that the transmission fluid is overheating. Engaging 4WD puts extra stress on the drivetrain, which *could* contribute to transmission overheating, but the light itself doesn't directly relate to the 4WD system's status. The problem is high transmission fluid temperature.

You should immediately:

* Stop driving. Continuing to drive with an overheated transmission can cause serious and expensive damage.

* Turn off the engine. Let the transmission cool down.

* Check the transmission fluid level. Do this carefully, as the fluid will be hot. Refer to your owner's manual for the proper procedure. Low fluid is a common cause of overheating.

* Check for leaks. Look for any signs of fluid leaks around the transmission.

If the problem persists after letting the transmission cool and checking the fluid, you need professional diagnosis and repair. Driving with an overheating transmission can lead to costly repairs or even transmission failure.