Transmission control module location on 1995 gmc k1500 z71 4x4

Look at the transmission control module. Sounds like a massive wiring harness problem too.

Whenever this warning light or any other stays on in the dash it is indicating that the systems control module (or the system sensor in the case of lights like low oil pressure, door open indicators etc.) has detected a fault, it then disables the system (this applies to ABS,TCS, TCM, SRS and BCM faults and others) as long as the light is on. You must now have the dealer hook up a special electronic diagnostic tool and "scan" the system for the fault code that is stored for the problem(s)

Legend of Abbreviations. ABS Antilock brake system.TCS Traction control system, TCM Transmission control module, SRS Supplemental restraint system, BCM Body control module

Whenever this warning light or any other stays on in the dash it is indicating that the systems control module (or the system sensor in the case of lights like low oil pressure, door open indicators etc.) has detected a fault, it then disables the system (this applies to ABS,TCS, TCM, SRS and BCM faults and others) as long as the light is on. You must now have the dealer hook up a special electronic diagnostic tool and "scan" the system for the fault code that is stored for the problem(s)

Legend of Abbreviations. ABS Antilock brake system.TCS Traction control system, TCM Transmission control module, SRS Supplemental restraint system, BCM Body control module

Take it an have it checked for DTC'S - diagnostic trouble codes . With warning light's on DTC'S are set in the ABS control module , the air bag control module ,PCM - engine computer or transmission control module . No guessing here ! Test an check

Hope this helps your out. I know the diagram and locator is a bit blurry but hopefully it gets what you need.
Drivers kick panel:
Front wiper 20A - Front wiper system Cigar 15A- Cigarette lighter Audio 10A- Audio, remote control mirror Air Bag 10A -Air bag diagnostics Stop lights- 15A -Rear brake light, high mounted stop light ECU B+ 10A - Shift lock actuator, transaxle controle module, radio, engine control module Room 10A - Interior light, clock, ignition key reminder, rear cargo area light switch ABS 10A- Anti lock brake system control unit ECU IG1 10A - Transaxle control module, shift lock actuator, ABS control unit, DRL unit Meter 10A - Instrument panel, back-up switch, electronics time control module, inhibit switch Turn signal 10A- Hazard switch ,front and rear turn lights, turn indicator IGN1 20A - Ignition switch ABS 30A- ABS pump motor TNS 30A- Tail light, license plate light COOL/FAN 30A- Cooling fan Cond/Fan 20A- A/C condenser fan Starter 15A- Start signal , Fuel pump Blower 25A- Blower Motor SR/ACC 10A - Ignition switch Hazard 15A - Hazard and turn signal light D/Lock 25A- Door locks ABS 30A - Anti lock brake system control P/W RH 20A- Power window motor right hand P/W LH 20A- Power window motor left hand IGN2 25A- Ignition Switch
Engine compartment :
Head 25A- headlights IG 2 30A- Ignition switch IG coil 15A -Ignition coil, condenser,generator IC regulator, diagnostic connector. O2 down 10A- Rear O2 sensor O2 up 10A- Front O2 sensor Fuel pump 10A -Fuel pump unit Injector 10A -Fuel injector ,camshaft positioning sensor, purge solenoid valve, EVAP, IAC actuator, Mass Airflow sensor, EGR stepper motor. fuel pump relay coil, vehicle speed sensor. A/Con 10A - A/C compressor controls, cooling fan BTN 30A- Brake light , high mounted stop light. Tail light LH 10A- License plate light, tail light , rear combo light, instrument panel illumination Tail light RH 10A-License plate light, tail light , rear combo light, instrument panel illumination Head low 15A- Headlight Head Hi 15A-Headlight Horn 15A- Horn

Inside kick panel

The vehicle speed sensor is not working, it is located in the transmission tailshaft. The computer uses this speed info to shift the transmission, and tell when the rear wheels are locked up so the ABS will function.

Fuses are listed here

* = maxi fuse

1*=50A I/P fuse panel
2*=40A blower motor relay
3*= 50A 4 wheel ABS module
4*=20a Main light switch-Instrument cluster
5*=50A Ignition switch, starter relay

6*=20A Transfer case relay
7*= NOT USED
8*=20A Auto Ride Control Switch/on off switch
9*=40A Auto Ride Control relay
10*=30A PCM power relay

mini fuses
1=10A A/C relay
2=20A Aux power point
3= not used
4=15A Fog lamps-Daytime lamps
5=10A Air Bag diagnostic monitor
6=10A Powertrain Control Module (PCM)
7=30A 4WABS module
8=30A PCM relay
9=20A Fuel Pump relay and RAP module
10= 15A Horn relay
11=15A Park Lamp relay-Main Light Switch
12=30A Main light switch--Multi Function switch
13=15A Heated O2 sensors, EGR Vacuum Regulator, EVR solenoid,Camshaft position (CMP) Sensor,
Cannister Vent Solenoid, A4LD Auto Transmission
14=30A Generator-Voltage regulator


Interior fuse panel (mini fuses)

1=7.5A Power mirror switch
2=7.5A Blower motor relay,PAD module,Air Bag diagnostic monitor
3=7.5A Trailer tow connector
4=10A Left headlamp
5=10A Data link connector (DLC)
6=7.5A Air bag diagnostic monitor, Blower motor relay, Passive deactivation Module (PAD)
7=7.5A Trailer Tow connector
8=10A Right headlamp, Daytime running lamps (DRL) module, Foglight relay
9=7.5A Stop Lamp switch
10= 7.5A Speed control-amplifier assembly,Brake pressure switch, Generic electronoc Module (GEM)
Shift lock actuator, Blend door actuator, Main light switch, RABS resistor, A/C heater assembly
Flasher
11= 7.5A Instrument cluster, Main light switch, RABS resistor
12= 10A Power window relay, Washer pump relay
13= 20A Stop lamp switch, Brake pressure switch
14= 20A Rear Anti Lock Brake system (RABS) module
**10A 4WABS module**

15=7.5A Instrument cluster
16= 30A Windshield wiper Motor, Wiper Hi-lo relay, wiper run/park relay
17=7.5A Cig lighter
18=15A Drivers unlock relay-All unlock relay
19=25A PCM power diode
20=7.5A RAP module GEM module, Radio
21=15A Flasher (hazard)
22=20A Aux power socket
23=15A Turn signals
24===not used
25= 7.5A GEM module, Instrument cluster
26= 10A Battery saver relay, Electronic Shift relay, Interior lamp relay
Power window relay,Electronic shift control module, transmission control
27=15A Switch,DRL, Backup lamp switch, DTR sensor,Instrument illumination dimming control module
Dome/map lamp, GEM,electronic shift,Interior lights,Glove box lamp and switch
28=7.5A GEM module-Radio
29= 15A Radio
30=15A Park lamps, trailer Tow relay
31===not used
32=10A rear blower
33=15A Headlamps, DRL module, Instrument cluster
34=7.5A Rear integrated control panel, CD
35=10A RABS test connector
36=7.5A CD, rear integrated control panel, memory seat, Message center Attached images __________________

I believe that this is what you are looking for.....
Fuse and relay locations--2nd generation power distribution box Layout- I think this is a good sticky candidate--



Fuses are listed here

* = maxi fuse

1*=50A I/P fuse panel
2*=40A blower motor relay
3*= 50A 4 wheel ABS module
4*=20a Main light switch-Instrument cluster
5*=50A Ignition switch, starter relay

6*=20A Transfer case relay
7*= NOT USED
8*=20A Auto Ride Control Switch/on off switch
9*=40A Auto Ride Control relay
10*=30A PCM power relay

mini fuses
1=10A A/C relay
2=20A Aux power point
3= not used
4=15A Fog lamps-Daytime lamps
5=10A Air Bag diagnostic monitor
6=10A Powertrain Control Module (PCM)
7=30A 4WABS module
8=30A PCM relay
9=20A Fuel Pump relay and RAP module
10= 15A Horn relay
11=15A Park Lamp relay-Main Light Switch
12=30A Main light switch--Multi Function switch
13=15A Heated O2 sensors, EGR Vacuum Regulator, EVR solenoid,Camshaft position (CMP) Sensor,
Cannister Vent Solenoid, A4LD Auto Transmission
14=30A Generator-Voltage regulator


Interior fuse panel (mini fuses)

1=7.5A Power mirror switch
2=7.5A Blower motor relay,PAD module,Air Bag diagnostic monitor
3=7.5A Trailer tow connector
4=10A Left headlamp
5=10A Data link connector (DLC)
6=7.5A Air bag diagnostic monitor, Blower motor relay, Passive deactivation Module (PAD)
7=7.5A Trailer Tow connector
8=10A Right headlamp, Daytime running lamps (DRL) module, Foglight relay
9=7.5A Stop Lamp switch
10= 7.5A Speed control-amplifier assembly,Brake pressure switch, Generic electronoc Module (GEM)
Shift lock actuator, Blend door actuator, Main light switch, RABS resistor, A/C heater assembly
Flasher
11= 7.5A Instrument cluster, Main light switch, RABS resistor
12= 10A Power window relay, Washer pump relay
13= 20A Stop lamp switch, Brake pressure switch
14= 20A Rear Anti Lock Brake system (RABS) module
**10A 4WABS module**

15=7.5A Instrument cluster
16= 30A Windshield wiper Motor, Wiper Hi-lo relay, wiper run/park relay
17=7.5A Cig lighter
18=15A Drivers unlock relay-All unlock relay
19=25A PCM power diode
20=7.5A RAP module GEM module, Radio
21=15A Flasher (hazard)
22=20A Aux power socket
23=15A Turn signals
24===not used
25= 7.5A GEM module, Instrument cluster
26= 10A Battery saver relay, Electronic Shift relay, Interior lamp relay
Power window relay,Electronic shift control module, transmission control
27=15A Switch,DRL, Backup lamp switch, DTR sensor,Instrument illumination dimming control module
Dome/map lamp, GEM,electronic shift,Interior lights,Glove box lamp and switch
28=7.5A GEM module-Radio
29= 15A Radio
30=15A Park lamps, trailer Tow relay
31===not used
32=10A rear blower
33=15A Headlamps, DRL module, Instrument cluster
34=7.5A Rear integrated control panel, CD
35=10A RABS test connector
36=7.5A CD, rear integrated control panel, memory seat, Message center Attached images __________________

I had the same problem with ABS light and speedometer, I was told that it is the transmission control module. It has not yet stopped shifting but I have had times where it just wont stay running. It will start and then stall. Hope this helps.

Check your battery terminal connections. Because so much of these trucks are computer controlled a bad connection at the battery will cause alot of electrical bugs. I had to replace my transmission about a year ago. Just prior to having that done my speedo was going crazy at times. The brake warning light usually means you have one or more calipers that need to be replaced. Start with the battery terminal connections.