Hello friends. I have an I6 SY Ghia AWD with the ZF 6HP transmission. High country mileage, well maintained. Recently replaced trans filter and refilled tranny with Lifeguard fluid. After a week on the road it started entering limp mode when cold and the gear selector indicator lamps all flashed when the fault occurred. The fault reset itself when the ignition was turned off, and after several repetitions the car was good for the rest of the day. But now it switches off about one second after starting and the OBD2 code is U0100 1/1, which translates as "Lost Communication with ECM/PCM "A".
I believe this code can be difficult and time consuming to diagnose so here's your chance to help.... I'm after advice/experience, and best of all, any reference to an industry cheat sheet showing how to diagnose this fault. I'm guessing that our local autoelectricians have access to such a service because obviously it would be valuable. PS: the inside of the transmission showed no signs of damage. The old fluid (50,000km+) was not much discoloured and almost no sludge on magnets. All comments and ideas will be welcome. Thanks and cheers Steve L
