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Code 81 and not shifting out of first

Michaeljp86

Michaeljp86

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I had this in the trcuk section and didnt get much help. Maybe someone who hangs out here would know. I get code DTC 81 - Transmission 2-3 Shift Solenoid Circuit. The truck has reverse but wont shift out of first. The transmission probably only had 500 miles in it when this happened. I put new solenoids in and it did nothing. The ground is good too.
 
check the transm pass trough connector pins,you can OHM the solenoids there too.

I had a bad VSS once on a 92 2w dr, had only first gear and reverse too,speedo did'nt work either.
 
if i remember well on the connector,the top most pin to the front is ground,the 2 pins to the left of the center are for the shift solenoids ,a DVM should measure over 2300 ohms,applying 12 volt you can hear them click.

The VSS can be checked for OHMs as well,should be over 1300 and close together. A pigtail will make life easyer on these.A CTS connector from a 6.5 will fit as well.
These things generate their own voltage as the reluctor wheels spin past them,the higher the speed,the higher the voltage.
I had one that failed when hot,but worked fine when cold.
Took a while to find that one.
 
Pin E is in the middle. Pin A is in the upper left. Ohms should be in the neighborhood of 20.
Like Bison said you can rig a battery and actually check it. A click can be heard.
If the circuit is failing there is a chance that it could be the solenoid or the wiring through the passthrough connector. Check for short from the pin A solenoid ground to transmission ground. If you are still having problems with the circuit check for resistance (ohms) from Pin A to the negative side of the solenoid itself by dropping the pan.
You can also drop the pan and with the ignition on and the truck not running Short the negative side to ground. You should hear a click. Make sure it is the negative side of the solenoid. Verify 12 volt side first.
 
I never tried putting power to the solenoids but I did check resistance. The manual I have says the shift solenoids are 20-40 ohms. I think one was 23 and the other 27. The pressure control solenoid is supposed to me 3.5-8 ohms and I think I had 7.4. The TCC solenoid was way off. It says 20-40 ohms and I had 8 IIRC. I'll piddle around with it today.
 
DTC 81

The TCM commands the solenoid “ON” and voltage remains high.

The TCM commands the solenoid “OFF” and voltage remains low.

All conditions are met for 2 seconds.

Commanding on and off is done through the negative side of the solenoid circuit in the computer.

Where I am not sure of is through Pin E Hot side if the computer uses it for reference ie.. dtc.

I am not sure exactly how the code is thrown from the computer. The negative side has residual electricity measured within the computer.
 
There is. Pin E which is in the middle. E provides power to the 1-2 2-3 and the TCC soleniod. They are controlled by separate grounding

Chances are you have power there. Doesn't hurt to check for power.
 
So if I pull the plug off and check pin E I should have power there with the key on?

Alos wouldnt pulling the plug out and driving it have the transmission in 2nd gear only? I tried that but the same deal, only first.
 
Pin E has no power to it, pin L which is just under F has 5V. There was some other pins in the same line as L that had like 11.5v.
 
So if I pull the plug off and check pin E I should have power there with the key on?
Click to expand...

Yes: you can verify power.

Alos wouldnt pulling the plug out and driving it have the transmission in 2nd gear only? I tried that but the same deal, only first.
Click to expand...
The transmission is supposed to drive in second gear only with the plug off.


With no power
The 1-2 shifting solenoid cannot be engaged.

The 2 to 3 shifting solenoid cannot be engaged
 
GenBiltstein said:
Yes: you can verify power.


The transmission is supposed to drive in second gear only with the plug off.


With no power
The 1-2 shifting solenoid cannot be engaged.

The 2 to 3 shifting solenoid cannot be engaged
Click to expand...

My transmission has first gear only with the plug off but reverse works fine, doesnt it need to shift into 2nd for reverse to work?

Where does the wire for pin E start at? The TCM?
 
Verify voltage at the plug first.

Verify voltage going to the PCM.
My books say there is an ignition feed. Not from the PCM.
Let me know what year and model truck and I will try to PDF it

I am 80% certain it is an ignition feed.
 
Well I changed the blown transmission fuse and now its shifts. :mad2:

Now it has code 85 DTC 85 - Transmission Gear

The fuse was fine before, when I was playing with it back it the winter I must have blown it some how. The one of the solenoids must have been bad. I never chacked the fuse after I changed the solenoids. :rolleyes5:

Its shifts hard from 1-2 everything else was fine. It shifted hard from 1-2 ever since he put the new transmission in. Unless the rear end causes the harsh jerk, he put a new rear end in it too and Im sure its not set up properly.

He put on a new TPS too.
 
Code 85 undefined ratio error.
Check or replace vehicle speed sensor(s)/wiring/connectors first.

You can switch front to rear,if the rear is ff'd it'll show no speedo.

Ohms should be very close together.around 1350 i think.
 
I had code 85 on my other truck too but its gone now. I pulled off the battery cables and will try it again tomorrow and see if it comes back. If it does Ill try to switch the sensors and check the ohms.
 
Well I changed the blown transmission fuse and now its shifts.

Now it has code 85 DTC 85 - Transmission Gear

The fuse was fine before, when I was playing with it back it the winter I must have blown it some how. The one of the solenoids must have been bad. I never chacked the fuse after I changed the solenoids.

Its shifts hard from 1-2 everything else was fine. It shifted hard from 1-2 ever since he put the new transmission in. Unless the rear end causes the harsh jerk, he put a new rear end in it too and Im sure its not set up properly.
Click to expand...

DTC 85 is undefined gear ratio. Clean the passthrough connector There is a transmission range pressure switch. Gives feedback to the computer.
Try this test. Clear codes. Drop into third. Drive vehicle in third. If no DTC 85 pops up then shift it into 4th.
Clean passthrough connector. Check grounding at powertrain with multimeter. Ohms. .5 or less you are good to go. anything higher take apart ground terminal and clean.

Reconnect clear codes and drive.

No go

Passthrough connector pins N P R are the pins to the TRPS switch. When you look at the connector they are on the bottom. No oil or contamination. go to dieselplace 4l80-e forum look through the sticky there.
There is an example of passthrough there.
 
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