Transmission codes after rebuild

[Mickey_7106]

Hello,
My brother had his transmission rebuilt and its throwing a few codes. The tech came out and is saying the tranny isn't receiving any electrical current. Does anyone know of a way to test this theory? Do i turn the key to On and probe all the pins to verify this?

Thanks

2001 tahoe 2wd.

P0740 Tcc circuit open
P0753 shift solenoid A electrical
P1810 TFP Valve Position Switch Circuit 3
P1860 Tcc pmw solenoid circuit electrical
P0713 Transmission fluid temp sensor circuit high input

 

[Mudsport96]

Well first thing to check is fuses. Then see if there is power at the chassis side plug. If there is power there, make sure that it is securely connected to the transmission. After that it's time to crack open the trans, but if it was just serviced...id send it back to the mechanic

 

[Just Fishing]

probably going to need to first check the plug on the side of the transmission, make sure it's in there.
then since this probably a 4l60e, pull the transmission pan to ensure everything is actually plugged in.
if you have a tech2, then you can also check each circuit to see if it's registering an open circuit (not plugged in).

 

[Mickey_7106]

Thanks yall. I just looked up the manual for possible fuses to look for. Does anyone know if the pinout changed throughout the years for the 4l60e? Getting different info online for what each pin is. I just ordered the vcxnano. Been eyeing it for a while. Hopefully it can help with this problem.

 

[rockola1971]

Thanks yall. I just looked up the manual for possible fuses to look for. Does anyone know if the pinout changed throughout the years for the 4l60e? Getting different info online for what each pin is. I just ordered the vcxnano. Been eyeing it for a while. Hopefully it can help with this problem.

Did you even verify that the WIring harness is plugged in to the tranny?

How exactly do you intend to get the various gear signals out of the PCM to check for correct signal on each wire to the tranny while the vehicle is in park sitting in your garage or driveway?

 

[Mickey_7106]

Did you even verify that the WIring harness is plugged in to the tranny?

How exactly do you intend to get the various gear signals out of the PCM to check for correct signal on each wire to the tranny while the vehicle is in park sitting in your garage or driveway?

Everything is plugged in. Not sure how I'm going to do it. That's why I'm here asking for help. I'm hoping the vcxnano helps with diagnosing. Only useful info i have from the mechanic is that there's no power going to the tranny. But in the meantime i want to see if i can test individual pins for voltage

 

[rockola1971]

Everything is plugged in. Not sure how I'm going to do it. That's why I'm here asking for help. I'm hoping the vcxnano helps with diagnosing. Only useful info i have from the mechanic is that there's no power going to the tranny. But in the meantime i want to see if i can test individual pins for voltage

I think you are missing the point. The only way for you to check the voltages is to have the vehicle setup in the correct configuration to output those voltages (from the PCM). And in order to do that you would either have to be rolling down the road or sitting on a vehicle lift in gear. Because of the quantity of codes and misisng voltages I would have to suspect that the problem is common to the whole tranny wiring harness/control system. And those common items are:
(1) Harness is unplugged at tranny or PCM side OR all of the wires in the tranny (which connect to that harness via the plug) were not attached to the various solenoids and pressure switch on the valve body.
(2) You have lost ground at the PCM which is G103 in the attached schematic.
(3) You have lost 12v + which is provided by IGN Fuse 10A and is fed down the pink wire to the tranny plug. This is an easy check with a voltmeter and can be verified quickly.
(4) Your tranny wiring harness has been completely cut through at some place or the pink wire is broken.

I would check the igntion fuse first and verify its not blown since its the easiest to check. Then check for 12v+ on the tranny PLUG pink wire. Let us know what you find on these 2 checks and we can torubleshoot from there.
One key thing to remember on MOST vehicle is that 12v+ is usually fed constantly to solenoids and relays. It is the ground that is switched on and off via the PCM, etc. If you have a look at the attached schematic you will see the switches for the various tranny solenoids are in the PCM. Those switches are actually transistors which are used to switch the circuits on and off. This is called a ground seeking system as far as controls go since the 12v is fed constantly but the ground is not.

 

[Mickey_7106]

I think you are missing the point. The only way for you to check the voltages is to have the vehicle setup in the correct configuration to output those voltages (from the PCM). And in order to do that you would either have to be rolling down the road or sitting on a vehicle lift in gear. Because of the quantity of codes and misisng voltages I would have to suspect that the problem is common to the whole tranny wiring harness/control system. And those common items are:
(1) Harness is unplugged at tranny or PCM side OR all of the wires in the tranny (which connect to that harness via the plug) were not attached to the various solenoids and pressure switch on the valve body.
(2) You have lost ground at the PCM which is G103 in the attached schematic.
(3) You have lost 12v + which is provided by IGN Fuse 10A and is fed down the pink wire to the tranny plug. This is an easy check with a voltmeter and can be verified quickly.
(4) Your tranny wiring harness has been completely cut through at some place or the pink wire is broken.

I would check the igntion fuse first and verify its not blown since its the easiest to check. Then check for 12v+ on the tranny PLUG pink wire. Let us know what you find on these 2 checks and we can torubleshoot from there.
One key thing to remember on MOST vehicle is that 12v+ is usually fed constantly to solenoids and relays. It is the ground that is switched on and off via the PCM, etc. If you have a look at the attached schematic you will see the switches for the various tranny solenoids are in the PCM. Those switches are actually transistors which are used to switch the circuits on and off. This is called a ground seeking system as far as controls go since the 12v is fed constantly but the ground is not.

Thanks, i really appreciate all the help. I'll be checking the truck tomorrow. will update with my findings

 

[Mickey_7106]

I think you are missing the point. The only way for you to check the voltages is to have the vehicle setup in the correct configuration to output those voltages (from the PCM). And in order to do that you would either have to be rolling down the road or sitting on a vehicle lift in gear. Because of the quantity of codes and misisng voltages I would have to suspect that the problem is common to the whole tranny wiring harness/control system. And those common items are:
(1) Harness is unplugged at tranny or PCM side OR all of the wires in the tranny (which connect to that harness via the plug) were not attached to the various solenoids and pressure switch on the valve body.
(2) You have lost ground at the PCM which is G103 in the attached schematic.
(3) You have lost 12v + which is provided by IGN Fuse 10A and is fed down the pink wire to the tranny plug. This is an easy check with a voltmeter and can be verified quickly.
(4) Your tranny wiring harness has been completely cut through at some place or the pink wire is broken.

I would check the igntion fuse first and verify its not blown since its the easiest to check. Then check for 12v+ on the tranny PLUG pink wire. Let us know what you find on these 2 checks and we can torubleshoot from there.
One key thing to remember on MOST vehicle is that 12v+ is usually fed constantly to solenoids and relays. It is the ground that is switched on and off via the PCM, etc. If you have a look at the attached schematic you will see the switches for the various tranny solenoids are in the PCM. Those switches are actually transistors which are used to switch the circuits on and off. This is called a ground seeking system as far as controls go since the 12v is fed constantly but the ground is not.

There's 12v coming from the pink wire at the round plug on the tranny. Checked fuses 15, 27, 30, 46, 49, and 53 under the hood and 5, 14 and 14 on the driver side dash. All good there. Spent most of the day trying to figure out how to get the vcx nano to communicate

 

[Mickey_7106]

Also check continuity of the battery to ground which i believe is G103 you mentioned. All good there too.