man i hope not i just bought this truck like four months ago

 

just wondering when disconnecting the sensors do i just go turn the ignition on everytime afterwards or what ive been taking some off one by one and no luck

 

cj


This usually means your ecm is not talking. It may be not talking to other sensors or it is dead. Check all sensors as suggested before. You also need to disconnect the battery for at least two min then reapply power. You may also want to reseat all the connectors on your ecm. Check for corrosion on these plugs and sockets. I get the same thing when i use my superchips and erase the factory program.

 

If it is a sensor short it should wake up instantly.
It could be a bad cluster too. You might have two separate problems

 

i checked the cluster and it gave me the codes and checked the gauges they all go full sweep

 

Any recent work done to the truck?
If you have a volt meter probe the TPS with the key on. One wire should have 5 volts.
If the 5v is there it isn't a shorted sensor.
At the data link connector (where a tech would plug a scan tool) you can measure your BUS voltages at pin 3 to ground and pin 11to ground.You should have 2.49v on 1 wire ans 2.51 on the other. pay close attention to the voltages the can't be the same on both wires (2.5v on each=bad)
\ xx3xxxxx /
\xx11xxxxx/
That's kind of what the data connector looks like under the dash on the driver side

 

thanks alot man ill have to check that out in the morning but the only work on the truck was my muffler which i put on a week and a half ago but i messed with it a little today but all i did was braze it no electricity and there arent any wires or lines around where i was brazeing

 

well im getting 5 volts at the tps but on the obd connector im only getting like .058 on both 3 and eleven maybe .057 it fluctuates what would that mean

 

just fixed it earlier figured id put some closure on it but it turns out the terminal in my obd II was loose or something my bro came down from uti and started taking readings in it and he wasnt getting all the volts that he was looking for and wiggled the terminal two and 10 around and my fuel gauge started working hopefully it doesnt do it again but you never know

 

I have been a auto tech for 30+ yrs. I am working on a diesel with no gauges and no bus, I have check the voltage and the ohms on the complete circuit. I had no communication with instrument cluster, could not perform the cluster test with trip button, displayed codes but no gauge sweep, disconnected each module, abs, air bag, trans, chime module, checked ohms from the obdII connector to each module including pcm no faults found, this truck runs no problem, the tach works, but no gauges or speedo, abs lamp on air bag lamp on and mil lamp on, pcm codes p1698, p1693...tcm codes p1693, p1694, p1687...The test sequence for vehicle runs, no gauge, no bus does not make sense, VIA Alldata, it says step 4 to disconnect the pcm connectors, jumper ccd bus + to ground, check for short to ground in scanner, well if you disconnect the pcm you have no comunication with scanner!!! am I missing something... I test the circuits by check voltage and ground all the way to the instrument cluster, with ICM removed I have 2.5 volts on each ccd bus circuit, I have all power on power in and all grounds out, if you start the truck and measure voltage between the ccd bus - & + their is a toggling voltage anywhere from 2- 2.5 volts which means those circuits should be communicating...Replaced the Cluster with a reman unit, now I can run the test and gauges will complete their sweep, I only have alternator gauge for a few minutes till "no bus" returns then nothing, I have disconnected and reconnected every connector and checked resistance and visually inspeceted each connector listed in the wiring diagram. with voltage on circuit do not understand hoe the pcm can be faulty any suggestions and info, need to move on to bigger and better things...I work on quit a few rebuilt vehicles and understand networks and multiplexing but this one has me...