bad trans harness possily?

[mudygmc]

Hey guys I switched valvebodies with a guy, or traded them he put them in. Now he keeps getting P0871 code and says the trans only has P N R and 4th. Looking at the trouble code list it says Shift solenoid E stuck open. I switched solenoids with him and he still has the same result. I am thinking that maybe the connector in the harness came loose or got messed up somehow. His is an 03 without the other solenoid on top (or the bottum) of the valvebody. I have a spare harness for my 05 valvebody with the other solenoid. Can he switch the harness and just leave the other connector unplugged? Both trannys worked so I don't think either solenoid is bad. Any ideas or info would be great. Thanks

 

[403turbo]

As far as the harness goes they can get messed up. I was going nuts trouble shooting shift valve D then C only to find after replacing the PSM and swapping solenoids around that the round plug on the main harness had crapped and the female connectors weren't making contact consistently. Major PITA.

Everything rang out ok with a meter, just wouldn't stay connected internally.

Give the wires at the suspect connectors a light tug and see if they stay put. Mine popped right out when cleaning some gunk off the wires with a rag.

Just my experience, not the only reason you can have issues. Maybe Mike will chime in.

 

[soot04max]

Hey guys I switched valvebodies with a guy, or traded them he put them in. Now he keeps getting P0871 code and says the trans only has P N R and 4th. Looking at the trouble code list it says Shift solenoid E stuck open. I switched solenoids with him and he still has the same result. I am thinking that maybe the connector in the harness came loose or got messed up somehow. His is an 03 without the other solenoid on top (or the bottum) of the valvebody. I have a spare harness for my 05 valvebody with the other solenoid. Can he switch the harness and just leave the other connector unplugged? Both trannys worked so I don't think either solenoid is bad. Any ideas or info would be great. Thanks

what was the reason for switching them?

 

[mudygmc]

what was the reason for switching them?

I put a transgo in the one he has in the truck. It was shifting to firm so he called around to a few shops. One guy told him that the new style valvebody with the extra solenoid wouldn't work right in his 03 that didn't have it. I figured it was just the trimmer valves but to keep him happy I cleaned and put new trimmer valves in his 03 valvebody. I gave him the valvebody and harness to switch now the truck only has P N R 4th and a p0871 code. I think he messed up the harness when he switched them, but don't know.

 

[gtmax]

Your friend has his old 03 VB back on but now with Transgo trim valves and it's throwing code P0871, right? If it worked before the swap the only thing different is the Transgo valves, are you sure the check ball and small spring didn't fall out? I personally believe the problem is a sticking E shift valve--center shift valve in the upper half of the VB.

 

[mudygmc]

Your friend has his old 03 VB back on but now with Transgo trim valves and it's throwing code P0871, right? If it worked before the swap the only thing different is the Transgo valves, are you sure the check ball and small spring didn't fall out? I personally believe the problem is a sticking E shift valve--center shift valve in the upper half of the VB.

He currently has the 03 in the truck. He has tried switching all the solenoids from the other VB with the same results. I think it would be quite a coincidence that both solenoids went bad all of the sudden.

 

[Bako_Dmax]

E shift valve is hangin up.

 

[stroke250]

Your friend has his old 03 VB back on but now with Transgo trim valves and it's throwing code P0871, right? If it worked before the swap the only thing different is the Transgo valves, are you sure the check ball and small spring didn't fall out? I personally believe the problem is a sticking E shift valve--center shift valve in the upper half of the VB.

x3

 

[soot04max]

before you go crazy trying everything. call the tranny god (mike l):thumb:. Im sure he can help ya over the phone to get the trucks back on the road. what truck is running the co-pilot? and is that the same truck with the transgo?

 

[mudygmc]

before you go crazy trying everything. call the tranny god (mike l):thumb:. Im sure he can help ya over the phone to get the trucks back on the road. what truck is running the co-pilot? and is that the same truck with the transgo?

I pm'd mike and he also said stuck valve. I just don't think both valves all of the sudden went bad. My truck has a sc4 and copilot so I have my original harness if needed.

 

[Bako_Dmax]

No one is saying something went bad it's very easy for dirt or other small pieces to cause a valve to stick especially the e shift valve or you may have overtourqed the vb.

It's a valve sticking I've had the same code before.

 

[mudygmc]

No one is saying something went bad it's very easy for dirt or other small pieces to cause a valve to stick especially the e shift valve or you may have overtourqed the vb.

It's a valve sticking I've had the same code before.

I am not saying it isn't but I don't think it is. The other vb shifted through all the gears but really firm. To make the guy happy I switched him the vb that was origionally in his truck. I flushed it out really good drilled the seperator plate and put in another set of tg trimmer valves. It had all his origional solenoids. When he installed it with his origional harness it had the codes. Yes I understand p0871 says pressure switch E stuck open performance, but if the harness had a short or bad connector would that have the same results. He took and switched all the solenoids from the vb that shifted firm and put them in this one with the same results. I don't think both valves would suddenly go bad. Especially with one only sitting for a day. I assembled the trans and switched them with him I did not do any of the install of tranny or the other vb. I am trying to help over the phone but don't know what to say. Everything I could think of we tried.

 

[Mike L.]

Pressure switch E stuck open means the pressure switch was not grounded by the stroke of the valve. The" performance " part of that description means the valve did not stroke.
The TCM commands a shift which fires the solenoid and allows fluid behind the valve to stoke it. The pressure switches are there to tell the TCM that the last command was followed through so that it can continue. If the valve sticks, the pressure switch doesn't ground and the TCM says I'm done; no more commands.

 

[mudygmc]

Mike how do you go about cleaning a valve. Like I said I am not doing it just relaying the info. Do you just pray them out with carb cleaner? I don't have one here to look at. I have never cleaned one before.

 

[Mike L.]

The valve body bore needs to be reamed with two special reamers. Vlave itself should never be touched except for washing.

 

[mudygmc]

I talked him into putting the 04 vb back in with the trimmer vlaves from the 03 and presto we have ignition. When I get the parts back is there anything I should look for as to why the 03 didn't work? I plan on rebuilding the trans and selling it and don't need any problems.