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Discussion Starter · #1 ·
Last drove my truck a few weeks ago and didn't have any problems. Hopped in it yesterday and found that the Service Engine Soon light is on now. It also seemed like it reved up higher than what it needed to in order to move what little it did. Does the transmission start in overdrive when the truck is in limp mode to help protect something. Also I had no reverse, it would not move at all in reverse. Just to busy right now to have it looked at, or even look at it myself. If anyone has any pointers please let me know or where to start at. Truck is a 01, which is bone stock.
 

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Probably stuck in third.... Sounds like a nsbu switch, Do a search on it and you will find it's verry comon on the earlier Dmaxes...
 

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If I recall pretty cheap part and easy to do if that helps...
 

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i have no idea what limp mode is..cause im like a rock! lol

but 1 time i took off fast then let off the gas right before the truck was gonna upshift and it did some hard narly shift then i stoped at the next light. then it felt like the tranny was sliping, it got about 15 degrees hotter by the time i parked. went to leave a hour later and it was fine.. idk weird
 

· That One Guy
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Do you have all the dash lights for D,N,R,3,2,1? If so then its not a NSBU switch it would be limp mode. When was the last time you changed your fuel filter and trans spin on filter?

Yes sicknick that would have been limp mode and it clears itself after the truck is shut off for a little bit.
 

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i have no idea what limp mode is..cause im like a rock! lol

but 1 time i took off fast then let off the gas right before the truck was gonna upshift and it did some hard narly shift then i stoped at the next light. then it felt like the tranny was sliping, it got about 15 degrees hotter by the time i parked. went to leave a hour later and it was fine.. idk weird
Probably limpoed yours for sure and it feeling like it slips is cause it was stuck in third gear... My guess is its fine now or feels normal again???
 

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Do you have all the dash lights for D,N,R,3,2,1? If so then its not a NSBU switch it would be limp mode. When was the last time you changed your fuel filter and trans spin on filter?

Yes sicknick that would have been limp mode and it clears itself after the truck is shut off for a little bit.
Thought you have reverse in limp mode????
 

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yeah never happend since and feels good. think my foot got lighter after that one.for a little
 

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· That One Guy
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Yeah never know what limp mode was until I did it a time or two after I got my truck then decided I better learn a little more about these trucks before I ruin it
 

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Last drove my truck a few weeks ago and didn't have any problems. Hopped in it yesterday and found that the Service Engine Soon light is on now. It also seemed like it reved up higher than what it needed to in order to move what little it did. Does the transmission start in overdrive when the truck is in limp mode to help protect something. Also I had no reverse, it would not move at all in reverse. Just to busy right now to have it looked at, or even look at it myself. If anyone has any pointers please let me know or where to start at. Truck is a 01, which is bone stock.
Its most likely the neutral saftey switch..mine did the same thing...when it was in gear did the dear light flash?
 

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Discussion Starter · #19 ·
I changed the fuel filter with a WIX about 3,000 miles ago, and the tranny filter at the same time. Tried er again this morning. The first time it went into all gears fine including reverse, none of the gear selections were blinking or flashing. However the service engine soon light was still on. So I shut her off and did the same thing with the same results, again it goes into all gears again with the service engine light still on. So I then tried starting it in nuetral, started fine and after it started it the service engine soon light went off. What are you guys thinking, are you still thinking the pnp nuetral switch?
 

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I changed the fuel filter with a WIX about 3,000 miles ago, and the tranny filter at the same time. Tried er again this morning. The first time it went into all gears fine including reverse, none of the gear selections were blinking or flashing. However the service engine soon light was still on. So I shut her off and did the same thing with the same results, again it goes into all gears again with the service engine light still on. So I then tried starting it in nuetral, started fine and after it started it the service engine soon light went off. What are you guys thinking, are you still thinking the pnp nuetral switch?
After I got mine to go into reverse the check engine light stayed on for a day or so.
 
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