Newbie with some trans Problems

[TahoeDrew]

I just joined up here. This is my 5th Tahoe and I've never experienced what's going on with this with the others so I'm kind of stuck. It's a 1996 5.7 4L60E Trans. It did throw some codes out they are p1860, p1884 and p1886. Recently the speedo and RPMs quit working all together and the check gauges light came on along with CEL. It shifts really sluggish when starting from a stand still and Over Drive will not kick in. All the other gears seem fine. The people at the auto parts told me to start with the speed sensor, so I got that but have not installed yet. My worries are that the codes are suggesting something totally different. I was hoping someone would let me know if I'm on the right track or not. Any help would be great! Thanks in advance

 

[SunlitComet]

The codes you are throwing are related to the Torque Convener Clutch Pulse Width Modulation Solenoid Valve and 3-2 shift solenoid valve. Not a speed sensor but the other shift valve are not for behind unless solved. First check fuse #20 10 amp transmission. It supplies + voltage to all the valves. About 5 total. If intact something is going wrong with the wire bundles either externally or inside the tranny pan.

* Inspect the wiring for poor electrical connections at the VCM. Inspect the wiring for poor electrical connections at the transmission 20-way connector. Look for the following conditions:
* A bent terminal.
* A backed out terminal.
* A damaged terminal.
* Poor terminal tension.
* A chafed wire.
* A broken wire inside the insulation.
* When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.

 

[TahoeDrew]

The codes you are throwing are related to the Torque Convener Clutch Pulse Width Modulation Solenoid Valve and 3-2 shift solenoid valve. Not a speed sensor but the other shift valve are not for behind unless solved. First check fuse #20 10 amp transmission. It supplies + voltage to all the valves. About 5 total. If intact something is going wrong with the wire bundles either externally or inside the tranny pan.

* Inspect the wiring for poor electrical connections at the VCM. Inspect the wiring for poor electrical connections at the transmission 20-way connector. Look for the following conditions:
* A bent terminal.
* A backed out terminal.
* A damaged terminal.
* Poor terminal tension.
* A chafed wire.
* A broken wire inside the insulation.
* When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.

Thanks for all the info. I decided to go out there this morning and scan the codes again. This time I popped a whole different set of codes, the codes that came up the first time no longer showed up, and I haven't even done anything to it yet. I know some of the codes are 02 sensor codes, but either way, here are the codes...
P0131
P0151
P0155
P0171
P0430
P0753

So, I'm kind of stumped right now. Any advice will be greatly appreciated.

 

[SunlitComet]

DTC P0131 HO2S Circuit Low Voltage Bank 1 Sensor 1

DTC P0151 HO2S Circuit Low Voltage Bank 2 Sensor 1

DTC P0155 HO2S Heater Circuit Bank 2 Sensor 1

DTC P0171 Fuel Trim System Lean Bank 1

DTC P0430 TWC System Low Efficiency Bank 2

DTC P0753 1-2 (A) Shift Solenoid Electrical-------------That is three valves now---two left

These all apears wire related Remove and check all four conectors on your computer. Mainly red and blue. Then go over every engine ground wire you can find. List below.

Under the hood in relay box check ecm I&B, eng I fuses.

G101 Sheet Metal at RH front Wheelhouse
G102 RH front of Engine Block, near Damper Pulley
G103 RH front of Engine, near Thermostat Housing
G104 RH top of Cylinder Head, near center
G105 RH front of Engine Block
G107 LH front Fender (Auxiliary Battery Ground)
G110 RH rear of Engine Compartment, below Heater Lines Gill RH rear of Engine
G112 RH front of Engine Compartment, below Underhood Reel Lamp
G113 On Radiator Support, near LH Headlamp
G150 (VIN M, R, J) RH front of Engine, near Thermostat Housing
G404 Inside LH Framerail, near rear Crossmember

If you can not find any fualts I can provide you with diagnosis data for each code. And you will need that scanner.

That many codes off of just two of the computer connectors suggest either damaged wiring/connector or a computer failure.

Can youu do a live data dump and post your readings?

 

[TahoeDrew]

DTC P0131 HO2S Circuit Low Voltage Bank 1 Sensor 1

DTC P0151 HO2S Circuit Low Voltage Bank 2 Sensor 1

DTC P0155 HO2S Heater Circuit Bank 2 Sensor 1

DTC P0171 Fuel Trim System Lean Bank 1

DTC P0430 TWC System Low Efficiency Bank 2

DTC P0753 1-2 (A) Shift Solenoid Electrical-------------That is three valves now---two left

These all apears wire related Remove and check all four conectors on your computer. Mainly red and blue. Then go over every engine ground wire you can find. List below.

Under the hood in relay box check ecm I&B, eng I fuses.

G101 Sheet Metal at RH front Wheelhouse
G102 RH front of Engine Block, near Damper Pulley
G103 RH front of Engine, near Thermostat Housing
G104 RH top of Cylinder Head, near center
G105 RH front of Engine Block
G107 LH front Fender (Auxiliary Battery Ground)
G110 RH rear of Engine Compartment, below Heater Lines Gill RH rear of Engine
G112 RH front of Engine Compartment, below Underhood Reel Lamp
G113 On Radiator Support, near LH Headlamp
G150 (VIN M, R, J) RH front of Engine, near Thermostat Housing
G404 Inside LH Framerail, near rear Crossmember

If you can not find any fualts I can provide you with diagnosis data for each code. And you will need that scanner.

That many codes off of just two of the computer connectors suggest either damaged wiring/connector or a computer failure.

Can youu do a live data dump and post your readings?

I only had a few minutes to mess with it this evening, since I got off work late. I did what you suggested and messed with the wires. I checked everything except the ground wires, it got too dark on me. But, what I did find out was, it may sound weird, but when I'm at a dead stop in the driveway and run the gear shifter through all the gears, as soon as I put it in 2nd second gear the gear indicator light goes off and the "check gauges" light comes on. Also, the tachometer is working sporadically now. And, when the indicator light goes off in 2nd gear, the tachometer stops working. Now, when I do get the tachometer to work sporadically, it runs great and the gears shift fine....it evens gets overdrive then. I didn't get a chance to re-scan the codes, but I'm going to be working on it all day tomorrow. I don't have a way to a live data dump. I know this may sound dumb, but should I go ahead and get all the solenoids or check all the wiring first?

By the way, I really appreciate all the help. Thanks, again.