Hey guys, was driving the 2001 TL for the past week after a transmission rebuild without issue. Today was a good 94 degrees out with high humidity. I was idling in a parking lot waiting for my daughter to finish her appointment and I noticed the D5 light was flashing. No check engine light.

I plugged in the code reader and I got the following codes:

P0710 - Transmission temperature Sensor
P1740 - Transmission 4th Gear Pressure Sensor

Now from what I understand, both are on the same wiring harness pigtail and plug in close to one another. So I am going to check the wiring for both before just ordering up sensors.

My question is, is this some sort of common failure and if I don't see anything readily apparent in the harness/connectors how far back should I look for the y-split for the common ground used between those and the rest of the harness?

I figure the ground got messed up with the transmission rebuild, but I am sure it is at a y-split for those two sensors, because I am positive there are a ton of sensors off the main ground point it leads back to, and I would be getting a slew of codes if that ground point was bad.

Or, if I test out the ground for both and it is solid, is it common for both of those sensors to go out (car has 231k miles on it)?

I just find it highly suspect that both codes were set and they are both off the same pigtail.

 

Maybe this video would help.


I have never done this so far since I got a brand new tranny back in 2007, since then it's driven about 120k miles without any issue. Only thing I've done to my tranny was frequent fluid changes, and recently did the transmission filter replacement which I think it was done for the first time and ever. The car's currently at 238k miles with its original engine and the 4th transmission which was the one I got back in 2007 shortly after the vehicle purchase.

 

Cbble, thanks for the reply.

I got under the car this morning and noticed that when they rebuilt the transmission they never snapped the wiring harnesses back into the clips. So I unplugged the sensors and checked them out, plugged them back in and then reclipped the harnesses.

After that I cleared the codes and went for a drive. After about 10 miles I stopped back at home, scanned the codes and only the P1740 4th gear pressure switch came back, so I decided to order up both the 3rd and 4th gear switches (come as a set) along with a new temperature sensor.

I will swap in the 3rd/4th gear switches first, clear the codes and drive it for a while to see what comes back. If the temperature sensor codes does (P0710) I will swap that in as well, but at least I will have it on hand.

 

So, I replaced both the 3rd gear and 4th gear pressure switches this afternoon. I then cleared the codes and went for a drive. No error codes on a 25 mile round trip.

Temps were only in the low 80s today, so in a week or so when it goes back into the 90s we will see if an error pops up with the transmission temperature sensor.

One thing I noticed in doing the pressure switches, is that the third gear switch had about 1/3 cup of transmission fluid spill out of it when I pulled the old one (car was up on ramps in a driveway that already had some slope to it), but the 4th gear switch didn't lose any fluid at all. There was a little fluid inside the switch when I turned it upside down. Just wondering if that is the sign of an issue somewhere, or if that is fairly normal?

 

Well, I got the P0710 Transmission Temperature Sensor error this morning. Luckily the sensor came in today.

I swapped it out, which, quite frankly kinda sucked, as the stock sensor housing broke off at the sensor.

Here is a tip: If the sensor breaks off like that you just need to be sure to have a slide hammer along with a screw-adapter on hand. The stock sensor is brass with a plastic housing, so you just need to drill in enough to cut into the brass a bit, then screw in the screw with teh slide-hammer collar on it. Once that is done put the slide hammer on and a couple of good whacks with the slide hammer and the sensor is out. You will lose the extra fluid that didn't drain out when you drained the transmission first, but that is OK as I just ran a finger around inside the clear out all the gunk that was built up and the transmission fluid coming out flushed it nicely. Put the new sensor in after using some ATF to grease up the new o-ring. I had to use a ratchet extension to tap the new sensor in place. Bolted it up and put everything back together.

So, I got it all done, filled back up with 3.5 quarts of fluid (seems like almost 4qts came out, but I figure I will just check the level and add as I need to), took it for a drive.

Turns out the fluid that came out was a nice red, but had a bunch of black stuff on the drain plug and some metal particulates at the bottom of the drain pan. After test driving it I am noticing that it flares going from 3-4.

Shifting 1-2 and 2-3 is great, maybe a little firmer than I would expect. But 3-4 has a nasty 500+rpm flare to it when cold. When hot (15 minutes of driving) it still has a little flare (maybe 100-200rpm), so I will see how it does tomorrow morning when cold (we will have 52 degree temps overnight). If it is closer to 1000rpm I will have him redo the transmission.

Now, before I go that route, can anyone confirm if one of the solenoids could be causing the lazy 3-4 shift?

I read about the adjustment tool, but I figure if it shifts between 2-3 just fine any adjustment to make 3-4 work better would basically over-stiffen the 2-3 shift, correct?

Is there possibly a lazy solenoid at fault for the 3-4 flare? I would rather see if something like that would work than go through the headache of trying to get this guy to stand by his work.

 

Update from this morning:

Took the car out early, 6am... Temp was showing 61 degrees outside. Dropped to 57 degrees before I got to the main road two blocks away.

While driving on the main road on the shift to 3-4 it flared at least 1000rpm each time and even did a 1500rpm+ flare once. Needless to say I am kinda upset.

 

thus why rebuilding this generation transmission and even the third gen transmission is futile.
dont be upset, just learn from it.

depending on how much money you have in it....i'd either sell it or throw more money into it by replacing the trans with a better unit (AV6). hope it's not your only ride.
Honda transmissions of this era ROYALLY SUCKED.

 

No, actually I have a number of other cars...

Problem is this is my daughters car. It is in GREAT condition. I mean you can literally eat off the underbody of the car it is that clean. No rust, no accidents, no damage, maintained to perfection. 231k miles, all original. doesn't burn any oil, engine runs awesome. No creaks, noises or anything else while driving. Hell, I didn't have as nice a car until I was in my mid-30s (OK, so I had newer sports cars, but they are not luxury cars).

Point is, for this car, it is probably worth it to fix "right". Hell I was glad I didn't order up the reconditioned OEM wheels to replace these (the ONLY corrosion on this car is the clear-coat for the wheels got ruined by clip on wheel weights).

The only problem I have with going to a AV6 is the fact that the 2001 TL has the speed-sensitive power steering that runs through the transmission. I really don't want to replace that.

 

The AV6 sticky describes how to loop-through the power steering. I believe you lose some low speed assist but that's about it. AV6 was the best decision I ever made.