Auto overdrive problem

[yeldogt]

I took the 02 Pathfinder on the highway this morning ... at about 75 mph the overdrive shut off. This is an LE with the auto transmission and the button for overdrive ... also auto 4wd transfer case.

I took my foot off the gas and hit the OD button a few times -- the light went on an off -- but no overdrive. As I slowed down I moved shifter into 2 .. to see if the transmission was working .. it was. When I put it back into D -- all normal .. I could turn OD on and off and all worked correctly. The car had been driven about 15 miles before the highway .. so it was fully warmed up

This is my third 02 LE (I like them). Have owned it about 3 years -- has around 70k on it. I changed all the fluids when I bought the car .. correct Dmatic fluid .. don't think fluid is the problem. No leaks.

I did have one issue back when I first bought the car -- maybe had it about 3 months and the OD did not go on at all ... I remember moving the stick and playing with the button .. nothing. Then a coupe of miles later .. all fine and has worked ever side ...until today.

I drove another 150 miles in mixed driving .. and all well.

Does anyone know how this overdrive works. It is odd that it was on and came off -- and the light stayed on. I guess it must have a relay .. but I wonder if the trans has some sort of solenoid ?

[rwardell]

i rebuild transmissions for a living, let me ask you a few questions.
does the vehical start off in second gear from a stop after you loose overdrive?(boggy, low power, over rev feeling)
have you had the codes pulled with a capable scan tool? (some parts house scanners only read engine data)
have you had the OD-off light flashing at any time? or the green shift position lamp in the cluster?

the shift from third to second is made by Shift solenoid A but it is also required for first.

[yeldogt]

Thanks for your help.

I have only had any issues twice -- and both at highway speeds. The car always shifts correctly otherwise .. I never notice any problems with the car not being in first gear at a stop. I did not have any codes read -- I have a simple code reader but I did not think to use it ... or try to use it.

Did not get the OD light flashing -- or the green lamp .... The OD light went on and off with the switch as normal but made no difference.

The other day the car acted like I switched off the OD ... That is what I thought I had done somehow. Cycling the switch made no difference -- I saw the light going on and off with the switch. Then I though the transmission failed and was slipping -- so I reduced speed and put the car in a lower gear and understood that it was working ..... when I put the car back into drive .... the OD worked normally?

The other time a few years ago and maybe 10k miles ago -- I entered the highway and the car would never go into OD. Same playing with the switch OD light working as it should .. I drove a few miles with the OD off ... got to my destination. When I restarted the car .. never any problems again.

The car is working normally now? very strange. Would have thought that the car would have noticed the output difference. Maybe It did not happen for long enough ... I did not drive very far before I put the car in a lower gear.

The transmission does not operate any different then my other 02's worked -- they do have a rather large RPM swing in the lower gears and do shift at a higher RPM when pushed.

I don't have any slipping or the "flair" at the shifts.

[nickelghandi]

I had this issue with my 99.5.. Went a long time with it happening intermittently. Very rare at first and by the time I figured it out, it was lurching on shifts, starting in 2nd or maybe 3rd gear, and not going into overdrive. For me it was the Throttle Position Sensor (TPS). I don't remember how much it was to buy but it wasn't too bad. It's easy enough to change too so if you are so inclined it can be done in an hour at the most. A shop could do it for cheap. You would want to get it diagnosed to make sure that is it first though.

[donald]

Very interesting. This is the second time mentioning the tps and transmission od issue. I have been experiencing the same issue when driving at highway speeds (after having driven about 10 minutes at city stop-go traffic before the highway on ramp) it seems the AT doesn't go into OD. I've tried switching the OD on/of also. Of the 3 times I've experienced this in the 3 years of ownership, I've been able to "remediate" the issue by restarting the truck and sighting into N while at speed and back into drive.

I'll try the TPS R/R and see if that helps any.
Crossing fingers.

[Jasecr123]

Did the TPS fix the issue? My 02 pathfinder is doing the same thing. Started out doing four times over three months, did it yesterday on my way to work, then today on he way to work and on the way home it would jump up to 3k rpms at 60mph and stayed like that the whole time on the highway.

[donald]

I did not change the TPS. The other reason I wanted to change TPS was occasional engine stall and stumbling when coming to a stop.
However, I had decided to bring the truck in to a shop to have it checked for the stalling/stumbling issue - the mechanic noted that I was low on ATF.
Since topping off ATF, I have not experienced any engine stall/stumbling. I also note that I have not had any issues with OD since my post from Dec'14.