4wd light stays on when the truck is in 2wd

clawhammer · 07-01-2009, 11:33 PM

It all started last Tuesday. It's late at night, I'm driving my truck (04 Titan, 4x4, ~90k miles) through the middle of nowhere in Oklahoma, on my way back Houston. All of a sudden I notice that the orange drivetrain indicator light next to the odometer (the one that shows the wheels) is gone and the 4LO green light is flashing. I end up pulling over and notice oil all over the underbody of the truck. It's coming from the transfer case. I drive to Walmart, buy ATF and tools, and fill up the transfer case. I put over 2 quarts of fluid in there, so it almost completely dry.

The next day I take the truck to the dealer in Houston. They replaced the rear oil seal. Drive the truck a couple of days, check underneath it again, and oil is still everywhere, so the truck goes back to the dealer. They find that a washer is missing. They cleaned up the truck, took it on 2 separate 20 mile test drives, and the truck is bone dry underneath.

I picked the truck up from the dealership today, and I'm still having problems with the 4wd system. Right now, it's no longer leaking fluid. However, after starting the truck, the amber 4wd light stays on, and the light showing the wheels next to the odometer is gone. Eventually it goes away and acts normal, but the problem intermittently comes back. Sometimes I will even notice the 4LO light flashing.

Any ideas on what it could be?

Just-in · 07-02-2009, 01:11 AM

sensor? or could there be a short... doesn't a blinking 4lo light mean it's in the process of shifting? hear any grinding gears?
does it shift into 4hi and 4lo ok?

clawhammer · 07-02-2009, 07:22 AM

Sensor? Probably, just which one?

no grinding gears, everything on the truck seems fine, besides the dash light.

The truck shifts just fine into both 4hi and 4lo

clawhammer · 07-02-2009, 09:30 AM

I drove the truck ~100 miles last night. It was acting up most of the time. This morning on my way to work, it was driving fine. I guess I'll just wait and see, at this point mechanically the transfer case is fine, it's an electronics problem.

clawhammer · 07-06-2009, 08:01 PM

I did some troubleshooting tonight following the factory service manual, and it seems to indicate the "Wait Detection Switch". I'm going to order a new part and I'll update this thread with the results.

clawhammer · 07-27-2009, 08:32 PM

Update:

I replaced the part that the manual refers to as the Wait Detection Switch. That other name for that part is SWITCH ASSY-NEUTRAL,TRANSFER. That however did not resolve the problem.

I went through the test procedure again, and this time it was pointing to the 4LO switch. I decided to replace the ATP switch as well if I was placing another order. Although the ATP switch was replaced by the dealer under warranty at 76k miles (truck is now at 91k), I figued it was $18.

Anyway, I replaced both of the switches, and afterwards, I didn't see a single 4wd light. So far I've only put ~35 miles on the truck since replacing them, but so far it seems good. I will update this thread after some time goes by just to be sure that the problem went away.

**walleeme** · 07-27-2009, 09:56 PM

I'll bet all that oil slinging around fouled one of those switches.
Glad you got it solved.