Low ATF level on the trail

[Nissanboy]

This might be a no brainer, but I'd like to throw it out there. I did a mountain trail today that peaked about 8,000 ft. Towards the top I started to have issues going forward, literally, on the steep sections. My 92 WD21 would lurch a lil, but not rev up or spin the tires even though it was loose rock. If I shifted into neutral I could rev the engine freely. As I was turning around to go back down the trail (with my tail between my legs) I noticed that in reverse I wasn't having the same issues. I tried backing up the hill once I was turned around and had no problem going up the hill in reverse. Never once did the engine stall or smoke like it was running rich due to the elevation. Anyway I had no problems making it home, and once home I checked the level of the ATF and it was definitely low. My questions is has anyone else had this happen on steep inclines where their rig would lurch, but not rev up in drive. It never did stall it just wouldn't go. I hope it is as simple as just my tranny bring low on fluid.

[alexrex20]

ya, it probably is that simple.

[NissanNut]

I agree. I have gone up some steep stuff. I am loving the auto. Add a tranny temp gauge. Mine was low on my first trip to OK this year, and the trans temp gauge was bouncing up and down. It got real hot a few times. I guess I had a big air pocket. When I got home I added an external cooler and I noticed the fluid was low.

[Nissanboy]

Ok so this has gotten a little more serious now. I was driving home from work today and stopped at a long light, so I put the ole' girl in neutral. Light changes and I go back to drive and my Pathy seems to be confused. It now only likes 3rd gear (auto) as in it won't go into other gears or shift regardless of throttle position or gear selection (1,2,or D). That makes for great hole shots let me tell you. Reverse does work FYI. Other than my trail issues this weekend I have had zero problems with the tranny. I haven't done much research on Nissan autos, but for something like this to happen just like that without warning it makes me think something like a sensor or solenoid took a shit. Coming from Chevy's I would immediately think a vacuum solenoid, don't know if Nissan's have that? My tranny doesn't leak and I just topped it off over the weekend. My coworker told me his old Pathy's tranny took a crap on him cause the coolant and ATF were mixing in the radiator. Anyone have any ideas? This could put a real damper in my plans to SAS this thing if it needs a $1k or more tranny rebuild!!!!!!

[alexrex20]

try an ATF change first. next i would try cleaning/replacing solenoids.

[Nissanboy]

I was reading the alldata file on my rig and it sounds like my tranny is stuck on failsafe mode. A primary suspect of this is the AT control module has a bad ground. I will check this when I get home later tonight. That would explain why this happened instantly with no warning. The symptoms include not starting in 1st gear when accelerating from a stop and only shifting into 2nd gear the shifter is placed in 1st. It sounds a little bit goofy, but it was mentioned in a TSB so apparently this has been an issue on more than one occasion. I hope it is that simple. I need to be focusing on a SAS not a shit transmission!

[Nissanboy]

I feel like I am writing to myself, but whatever maybe it will help people out in the future. I got home last night and pulled the AT control module which is behind the passenger rear speaker on WD21. You have to remove the plastic interior panels to access it. I tested the grounds and all is good there. I ran the AT self diagnosis mode and it is as follows:

1.Start the engine and warm it up to normal operating temperature.
2.Turn the ignition switch OFF.
3.Set the A/T mode switch to AUTO.
4.Turn the OD switch ON.
5.Move the gear selector to PARK.
6.Turn the ignition switch ON. (Do not start the engine.)
If the POWER light comes on, continue on. If not then the A/T Control Unit is probably bad.

1.Move the gear selector to the D position while stepping on the brake pedal.
2.Turn the ignition switch OFF.
3.Turn the OD switch OFF.
4.Turn the ignition switch ON. (Do not start the engine.)
5.Move the gear selector to 2.
6.Turn the OD switch ON.
7.Move the gear selector to 1.
8.Turn the OD switch OFF.
9.Depress gas pedal fully and release it.
10.Read the POWER lamp.
The POWER lamp will start blinking to indicate the stored codes. There will be ten flashes in all. The way it shows the code is by a long flash. So a code three would flash like this:

Short - Short - Long - Short - Short. The short flashes are one second and the long flashes are two seconds long with a one second pause between flashes.

[Nissanboy]

On my rig it showed a code 4 and code 7 which means the shift solenoid A and torque convert clutch solenoid are having issues. So I began my tear into the tranny to pull these and see if they are working correctly. About halfway through the job I noticed the wiring loom from the tranny had come loose along the firewall and has physically touched the exhaust manifold. I am sure this is causing a false ground. Anyway tonight I will get the wiring harness out so I can repair or replace it from a JY if needed. I really want to get this wrapped up this weekend so I can focus on bigger and better things!

[NissanNut]

Nice find!!!!

[Nissanboy]

So it is really fun to pull the exhaust crosspipe just to get the tranny pan off. Way to go Nissan! Anyway as I get further into this issue it is just more and more frustrating. I pulled the pan off and immediately inspected the TCC solenoid. I did the resistance check as recommended by alldata and everything is fine. I checked continuity and resistance across the harness coming from the trans to the connectors on the pasengers side fender well. I did the same thing for the wiring back to the AT control module. As far as I can tell everything is within spec. The nice thing (sarcastic tone) is some previous owner cut all the wires from the trans to the fender well as they have all been spliced back together. I am almost starting to think it may be the AT control unit. A sure sign that a TCC has gone bad is your vehicle will die when you put it in gear OR when coming to a stop. I didn't have either of these issues. I do have a friend that is a certified mechanic that is going to look up in his database what he can find on my trouble codes. He tells me that alldata is crap and will lead you in circles. I hope he is right!