What is wrong with my LC? Transmission? Diff? Help.

[Jimmy V]

1999 LC 100 series with 105k, everything in good condition, bought at 85k from a dealer, did 90k service including tranny flush, AAMCO guy said it looked like it had already been flushed once. Only relevant mods are BFG KOs, just over 32", no rubbing. No roughness or noises shifting, no error lights on the dash, I don't use it for towing, although I don't know what my predecessor did. Florida 100 originally, one-owner, all dealer-serviced before I got it, now on its second Vermont winter. Taken off-road frequently in the summer.

Today I drove through between 6" and 1 foot deep snow for about 45 minutes. As I was descending a hill, I manually shifted into 2. Transmission held the gear all the way as I coasted down the hill, and at the bottom, I shifted back into D. The transitions were as smooth as always.

As continued driving in the flat, it seemed a little sluggish at first, so I pushed the gas pedal down a little. Very, very slight response. Tepid, I'd call it, with no downshift. Pushed it a little further. Nothing. Pushed it to the floor board. Nothing. No shift. No power.

I tried shifting into neutral and then back into gear, but issue continued. Top speed was effectively 30, about 18 up a moderate hill. Tried shifting into 2 and flooring it. Accelerated like a Winnebago. I can stop and start just fine, and it holds in P. Drove for about 15 minutes to work after the issues arose with no error light.

I am a bad mechanic and a worse diagnostician, plus I have bad hair. Please help.

 

[AimCOtaco]

Press center diff lock. If center diff lock gives you drive back then you have broken something in the front end, most likely the diff or a CV.

 

[Trunk Monkey]

Check engine light? I'm going with limp mode for something, maybe coil.

 

[Jimmy V]

No check engine light. I did have to replace a coil recently but when that occurred, not only did I get my check engine, it was flashing within about 20 seconds. Plus I could smell it and the engine ran rough. Right now everything seems ship shape, with no light.

 

[Jimmy V]

Update: Like batman or a Dodge Raider, it disappeared as suddenly as it arrived. Will update if there are further events but at the moment it seems I'm in the clear. I visited with my mechanic who concluded "something froze."

 

[badlander]

I concur with Trunk Monkey. Sounds like limp mode kicked in for some reason. It's happened to me twice and both times I shut it off and restarted after a minute or so and it was fine. Maybe yours needed a few more starting cycles to get it cleared......

 

[Jimmy V]

What I don't understand is this - if it enters limp mode, the computer must have a reason for doing so. Are you telling me that a Japanese car wouldn't show a code after going to limp mode? I might expect such logic from a Dodge Ram or something, but this seems incredible.

 

[AimCOtaco]

Every time mine has limped the Engine light has come on and set a code.

 

[badlander]

Yeah, It's been a couple of years since mine did it. It has not happened again since I started cleaning the mass air flow sensor and throttle body on a yearly basis. I don't remember if the light came on or if their were any codes. Did you check for codes?

 

[Trunk Monkey]

Triggering the CEL requires the problem to be either severe or reoccurring. It keeps a one off issue from sending you to the dealer unless it's really necessary. If a fault occurred, it would be stored in the ECU so that if the situation happens again, it will pull up the stored info and light the CEL if needed. A OBD reader can check for stored codes.