Truck Won't Come Out Of 1st

brockw08

brockw08

12 too many valves...
Joined
Sep 4, 2007
Messages
319
We've recently been having problems with our 1999 automatic not shifting out of first. It simply will not pull another gear. Max speed is about 20MPH, and it just will not shift no matter how hard it is pushed. What could be wrong with this thing? The truck is BONE stock, and has been its entire life. 90,000 miles.
 
the trans is either smoked or you have a problem in the valve body. being stock has nothing to do with it. you pull any weight and thats all it takes. i work in a trans rebuild shop and i see this all the time. take it to a pro, trust me
 
Change the Transducer in the valve body, and also take out the Govener Pressure Solenoid and pop the screen off of it and clean it really good and you should eliminate your electrical problem. If That doesn't do it then you probably killed 2nd gear band.

Lavon

Transducer is $83 @ the Dealer and easy to change
 
LAmiller said:
Change the Transducer in the valve body, and also take out the Govener Pressure Solenoid and pop the screen off of it and clean it really good and you should eliminate your electrical problem. If That doesn't do it then you probably killed 2nd gear band.

Lavon

Transducer is $83 @ the Dealer and easy to change
Click to expand...
As far as transmissions go, I'm retarded. Any info on where the Transducer and Governor Pressure Solenoid would be? Also, the truck has never pulled any weight whatsoever. It has never even been hooked to a trailer. Grandpa truck only!
 
Drop the pan and you will be able to see the Transducer and Govener Pressure Solenoid on the passenger side of the Valve body - its the only two sensors that the electrical wiring harness run to in the valve body. You will need to remove 3 7/16 in bolts and 2 torx bolts to loosen the bracket that holds the govener Pressure Solenoid... unplug the solenoid then pull down hard on the bracket to remove as the pressure solenoid has an o-ring and will be tight. Once the bracket is off then you can remove the Transducer( Black sensor with 4 pin flat connector).

once everything is out take the Governor solenoid and GENTLY pry the screen off of the top with a medium size flat screwdriver and clean it really good with brake cleaner then put it back together with your new Transducer.

Lavon
 
Pull the tranny relay, that will eliminate the electrical part of it. I have had issues with the wiring harness on mine. If the ground wire to the govenor pressure solenoid is grounded, it is keeping you from getting any govenor pressure. This will hold it in first. Pulling the power train relay, then pull the tranny to manual 1. Drive and shift to 2, and then to D, You will not get first gear again until you relieve govenor pressure by going to neutral. This should guide you to see if it is electrical or hydraulic. Even if the second gear is toast you should be able to get third gear. We all know how fast the stock trannys shift.
 
Yea...I drove without a second gear band for a while...it'll go from 1 to 3rd almost as if it is natural...


(i did it due to the lack of sufficient funds...suncoasts are $$$ but well worth it)
 
Ok guys, I pulled the transmission relay, and the truck shifted through all the gears fine when using the gear selector (1,2,D). So, what now?
 
In the 99, I the Transducer isn't held in by that bracket, but it has a clip to hold it in position. Not a likely scenario, but if that clip were to fail, the transducer could pop out of its like port that it plugs into, this would cause it not to read the pressure and it wouldn't shift out of 1st. I had a similar issue with mine. Like these guys said, there are lots of things it could be but start checking and trouble shooting parts. Start by checking the relay, however I would guess your problem lies with these electronics.
The gov. pressure sensor/temp sensor is the tranducer. The gov. pressure solenoid is the other one to look at.
Entire valvebody
valvebody.gif

Gov. portion of the valvebody, located on passengers side.
transducer.gif

Sean
 
sstockton said:
In the 99, I the Transducer isn't held in by that bracket, but it has a clip to hold it in position. Not a likely scenario, but if that clip were to fail, the transducer could pop out of its like port that it plugs into, this would cause it not to read the pressure and it wouldn't shift out of 1st. I had a similar issue with mine. Like these guys said, there are lots of things it could be but start checking and trouble shooting parts. Start by checking the relay, however I would guess your problem lies with these electronics.
The gov. pressure sensor/temp sensor is the tranducer. The gov. pressure solenoid is the other one to look at.
Entire valvebody
valvebody.gif

Gov. portion of the valvebody, located on passengers side.
transducer.gif

Sean
Click to expand...


Wouldn't not reading governor pressure send it to limp, which would be going to D?? Check the speed sensor?? I almost bet that is it. I forgot all about it. If the PCM doesn't see the rotation of the output shaft it will not command an increase in governor pressure. I would check the wiring, but just swap the speed sensor, it is on the passenger side of the tranny toward the rear. Like a 15/16" plastic plug with a 2 wire connector.
 
I have a brand new one, sell it to you for half of what the dealer wants for one.
 
When mine did this it was the output shaft speed sensor cost $36 bucks and took about 10 minutes to change.
 
Mine did this when the gov. pressure sensor popped out. My experience with losing the output speed sensor was losing 1st and 3rd. Gov. Pressure too high throws it into limp mode, but not reading gov. pressure didn't. This is just my experience though, so I'm sure there are other possibilities.
Sean
 
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