no reverse stuck in third. Many codes??

[timlb703]

This truck is a 2004 4500 gas 8.1. Getting codes p0763, p0768, p0773, p0841, p0871.

 

[Mpsoldier]

limp mode for some reason. allison behind the 8.1 so possible change the spin on.

 

[timlb703]

Truck has reverse sometimes and third gear start. Replaced the nsbu switch will a new one form allison. No change.

Dropped the pan. Have no power to three solenoids. Checked plugs look good.

Took a tcm out of a lly and didnt change anything.

Please help any ideas???

 

[Mpsoldier]

allison correct? erase codes and come right back?

 

[timlb703]

Yes allison codes come right back .

 

[timlb703]

This all started because the truck stalled and i put it in nutral and started it pulled it back down to drive and this is what I got.

 

[Mpsoldier]

if the transmission is warm does it do the same thing. i know it may sound stupid but my trans had a simular problem. only did it when it was cold. Once it got warm you can clear the codes and it would be back to normal.
2nd does your shift indicator light come on?

 

[timlb703]

yes shifter light is correct and in the correct gears. It started warm and acts the same cold.

 

[Mpsoldier]

send mike l a pm see if he has anything for you.

 

[timlb703]

Anyone??

 

[Mike L.]

Which code came first? List them as they showed numericaly.

 

[Mike L.]

Sounds like you have lost 12V to your TCM feed. Check wire 231 for 12V at the TCM.

 

[timlb703]

trying not to sound like a meathead but I pulled the plugs on tcm and am not seeing numbers. It is on a 4500 chevy 8.1 gas.

 

[duramaxdiesel]

A Kodiak?

 

[rgullett83]

ign switch?

 

[Mike L.]

ign switch?

Possible.
To see the wire #'s you need to unsnap the end of the harness to see them.

 

[timlb703]

What wire color and location is the 12v power feed into the main plug in the rear of the transmission. I want to make a jumper wire. I don't have 12v to transmission.

 

[timlb703]

Sounds like you have lost 12V to your TCM feed. Check wire 231 for 12V at the TCM.

Nailed it. Ran a new wire. Works great thanks.