45RFE Transmission.

Yesterday my truck started up in Limp mode and the CEL came on. This is not the first time that this has happened. I turned off my truck and restarted it. The truck drove fine after that. I immediately went to o'reillys and read the codes.

I have the following codes:
U0100- Lost Communication with ECM/ PCM
U0101- Lost Communication With Transmission Control Module
P0700- Transmission Control System (Malfunction Indicator Lamp Request)
P1603- PCM Internal Dual-Port RAM Communication Failure
P0882- TCM Power Input Signal Low
P0876- Transmission Fluid Pressure Sensor/ Switch D Circuit Range/ Performance
P0988- Transmission Fluid Pressure Sensor / Switch E Circuit Range/Performance
P0871- Transmission Fluid Pressure Sensor / Switch C Circuit Range/Performance
P0846 -Transmission Fluid Pressure Sensor / Switch B Circuit Range/Performance
P0869- Transmission Fluid Pressure High

Personally, I think it's an electrical issue. Maybe there is an issue with the connectors to the PCM or to the battery. I would like to get a second opinion on this to help me figure out where to start troubleshooting.

I created a spreadsheet with the information from the Factory Service Manual. I would appreciate any help or information. Thanks.

 

check all negative connections for corrosion, also when was the battery last tested, could possibly have a cell crapping out.

 

Did someone fix this problem before.

 

I have replaced the trans, the pcm, the idle position sensor, radiator, water pump, battery, and the cam position sensor and still having the same issue has anyone figured this out

 

Check battery connections, and all grounds. Actually check them with a voltage drop check. Assuming that all checks out good check the wiring harness for shorts.

 

Well I finally bit the bullet and took my truck to the dealership they told me the TIPM [Totally Intergrated Power Module] and the Front Control Module needed to be replaced that they ruled out everything else. Need less to say they wanted to charge me $2500 to replace them. So I believe in just going to order the parts and do it myself. I just was wondering how the FCM has anything to do with the transmission. I thought it was just like tach and lights and instrument cluster.

 

The FCM also controls the transfer case shift motor.You can send out the FCM for testing and repair,buy a refurbished one or a used one.New oem units have long been discontinued AFAIK.Don't forget to carefully check with a magnifying glass for corrosion on the terminal pins on each side of the connectors and clean real well with contact cleaner.

 

Does the FCM have to be flashed like the PCM or is it plug and play

 

FCM is a plug and play deal.Completely disconnect both battery terminals before you begin.

 

Ok thanks