Code U2104,2105 and P0700 comes up I try to clear them. The codes go off and I drive truck no problem. When I cut off the truck and restart it the codes comes back on. Can the ignition switch cause this? The tech2 says that I have a bad interminted problem in the FICM and TCM the tech2 cleared them and they return when I resart the engine.
U series are communication errors between computers. P0700 is ECM reporting that the TCM is claiming some kind of problem. I'll bet it's a TCM communication code.
Different errors are tested differently.
Some are testing at KEY ON, some are tested when the engine starts, some are tested went the water temp comes up, and some are tested constantly.
Check your bale connectors and ECM/TCM connectors. Look for bent or pushed in pins. Check ground straps. Look for exposed wires that have been rubbed through.
