Throwing TCM codes, need help!

[juscruzn]

I warmed up the truck and went to Costco first thing in the morning, about 4 miles away. After about 45minutes in the store, I got back in the truck and about 1/2 mile down the road truck limp's and MIL comes on. I pull over and check the codes. (BTW, truck only has about 37,000 miles - (I know, Duramax abuse...) and I recently changed both batteries.)

P0700
p0763
p0768

I reset DTC's, and almost immediately MIL and the following codes.

P0700
p0763
p0768

I reset DTC's and again, MIL, and being only a few miles from home, with the check engine light on, I try and drive home. Put it in drive and give her gas. Barely moved, felt like 5th gear from a dead stop. Checked codes again.

P0700
p0763
p0768
p0846
p0871

I reset again, and this time it felt like I went into 2nd/3rd gear, good enough to get it moving and home.

Last I checked, MIL on with the following codes.

P0700
p0763
p0768
p0846
p0871

I have a couple of ideas, but I thought I'd ask the experts before I try anything.
Thanks for your help!

 

[THEFERMANATOR]

Checked the fluid level yet? You have codes for all 3 shift solenoid pressure circuits which normally indicates a serious wiring issue, or loss of prime.

 

[juscruzn]

Yes, I checked while hot and running. Within full range.

 

[juscruzn]

Thanks for your input. I appreciate any help or suggestions. I checked what wiring I could see out of the tranny. No obcious signs of damage. Any other suggestions? Anyone?

 

[Mike L.]

Start checking for voltage at the TCM. You are not getting 12V to the trans.

 

[juscruzn]

Thanks, Mike! In particular, would pin 231 be a good place to start looking?

 

[Mike L.]

Thanks, Mike! In particular, would pin 231 be a good place to start looking?

Yes

 

[juscruzn]

I checked for voltage at the TCM. On the cable going to the "G" port I have voltage on various pins. Cable going to the "R" port I have no voltage. Is that normal? I've check all the fuses under the hood and drivers side door panel.