1999.5 QX4 Blinking 4Lo light when driving long distances

[mfas12]

Hi everyone, I have an odd problem with my 99.5 where if I've been driving for a couple hours or more on the highway at a time (only on drives to and from college 9 hours from home) my 4Lo light will start to blink, and my wheel indicators will turn off (both intermittently), and if I shift to park the atp light comes on but it engages park just fine. I think something might be overheating since the only time it didn't happen was when driving to school after winter break when it was below freezing out for the entire drive. If I stop for 5+ mins it will go away for about an hour and then come back. If I wait <5 mins then it won't go away. Changed the Transfer case fluid a month ago and it looked like normal old worn out oil (I hope that was the problem, figure bad fluid could allow stuff to heat up) but haven't gotten to drive long enough to confirm if the problem is fixed. I saw a bulletin for the frontiers that had a similar problem due to a bad atp switch. Anyone had a problem like this before, I don't think it's engaging 4lo as I am going highway speeds and it still feels like 2wd but I want to try and be sure just in case I'm running my transfer case down or something.

[nickelghandi]

Not sure if it is the same, but in my 2004 Pathfinder I get the 4WD light intermittently. Occasionally it will stay on for a long time. I have a thread on here about it. So far I haven't figured it out. I get similar symptoms to you.

My 4WD light illuminates solid, doesn't blink. My drive indicator (little green tires) go dark. I also cannot use 4WD while the light is illuminated.

Until I saw your thread, I didn't think about it being heat related. For me it also only happens while driving although not for as long as you. Once the light is on, sometimes it will go off after a few minutes or after I shut down the vehicle for a while. Sometimes it will stay on even after the car is shut off overnight.

If you do figure this out, please post back here. I would love to know what it was. If I figure mine out, I'll do the same.

[mfas12]

Could be heat for you, the service manual says that blinking of the 4WD light starts (on the 99 qx4 fsm), but will go away if it gets better (intermittent). For me, the symptoms are almost the exact same except with the 4lo light, not the 4wd light as expected (tbh wonder if something shorted from the 4wd light to the 4lo light or something). I'd change the transfer case fluid, mine looked like old oil and nasty, prob the cause if you are getting overheating doing the normal driving. If thats not the problem it prob should get new transfer case oil at its age anyway (I used Castrol transmax multi-import and its been doing good/should be matic d equivalent).