Well after checking into the no start issue, I believe that I am experiencing an issue with the TCM. Also found out that my keep alive memory is showing a fault, 0 volts. The truck will not start unless persuaded to do so by jumping the starter wire and then it won't move in a forward direction except in 3rd gear only. Reverse works, but no reverse lights, and the parking sensors are also not functioning. Does this lead anyone else to believe that the TCM has died, or could it have something to do with the power supply to the TCM? I cannot find where power is supplied from for this unit.

Thanks-

 

PCM may be affecting the TCM not allowing the xmsn to shift properly...Wait a second...is this the same truck you're talking about with the power draw?

 

ok... what is the xmsn? Truck runs fine, driveability along with not starting with the key seems to be the issue, but the autoenginuity scanner is showing a communication failure with the TCM. When I try to log directly into the TCM the scanner states that it cannot be found

 

power draw? no

 

xmsn = transmission....sorry...military jargon

 

I was curious if you ever figured out what your problem was. I have the exact same thing. Customer replaced the batteries and now has a no crank condition. Starter relay chatters and starter halfway tries to engage. I can jump the starter relay and get it to crank and start up fine. Relay pins have good key on voltage, and good 12 volt signal when moving key to start position. It seems to be a problem with the ground side of ther starter relay, which I'm assuming is controlled by the TCM. Can communicate with the PCM ok and no codes logged, but when I try and receive TCM codes it says no communication. Overdrive light is not working and tranny is stuck in 3rd gear. Have checked all fuses and relays, main hots and grounds and can't find anything. Is the TCM/PCM built into one box on these things? Any help would be appreciated. Thanks!

 

I did get mine fixed and I apologize for having not listed what I found. Thought I had done that. Anyway, I ended up pulling the fuse block and simply removing and re-installing ALL of the plugs on the back side. After I did that I immediately began getting communication with the TCM again. Problem was a bad connection and the TCM had no power/ground. Hope this helps and that your problem is as easily solved.

 

Thanks for responding. This post was the only thing I could find anywhere that sounded like the same problem I was having.

So I tried the same thing, pulled the fuse block out and checked all the connections. No signs of corrosion or anything strange. Cleaned up all the connectors with contact cleaner and reinstalled fuse block. Sure enough truck started fine and tranny is shifting normal again. Very strange and I guess just a weird coincidence that it happened after the batteries were replaced. Thanks again for the help!

 

I having transmission issue , tow haul flashing , only 3 gear , no back up lights , no start after it warn , idles up after its started , I replaced the TRSensor in the transmission , checked the plugs behind fuse panel I was told it's the tcm / pcm , if I turn key on after it hit and start it manually it starts right up , now mine is a title 2004/ build date is 9/03 which I told only 03 pcm will work, so I have a 03 f250 6.0 automatic aswell , can I put that PCM in the f450 to see if it's the issue , or is there a way to test my PCM thx Ben Gotti

 

Was it a short term fix or has it been problem free?

 

[QUOTE=justinmix;9262861]I was curious if you ever figured out what your problem was. I have the exact same thing. Customer replaced the batteries and now has a no crank condition. Starter relay chatters and starter halfway tries to engage. I can jump the starter relay and get it to crank and start up fine. Relay pins have good key on voltage, and good 12 volt signal when moving key to start position. It seems to be a problem with the ground side of ther starter relay, which I'm assuming is controlled by the TCM. Can communicate with the PCM ok and no codes logged, but when I try and receive TCM codes it says no communication. Overdrive light is not working and tranny is stuck in 3rd gear. Have checked all fuses and relays, main hots and grounds and can't find anything. Is the TCM/PCM built into one box on these things? Any help would be appreciated. Thanks. We had same issue. We found the ground wire to the box under driver on frame rail had rusted off. Fixed that and started up with the key.