I have a 2003 Expedition 5.4 It runs ok but I have a list of codes, I am going to put them all in here but the one I am most concerned about is u1073 (invalid or missing data for engine coolant from PCM) as it seems to have appeared after I changed my coolant. Engine runs fine, temp gauge works, although blue-driver shows that I never get much warmer than 170. I bought a 180 degree thermostat but have not installed it yet. I am also concerned about u1059 (transmission position data invalid)It shifts perfect so I am not sure if I need to worry about that. Here is the entire list of codes below. If anyone notices anything important about any of this stuff please let me know. This is my work truck and I want to keep it working as long and cheaply as possible. I am planning a 1200 mile round trip soon. Thanks Scotty! And thanks anyone else who has suggestions.
b2900 vin mismatch
c1805 mismatched abs /tcs module.
u1262 scp data link fault (seems like something with the seatbelts or tpms)
u1073
u1123 Invalid Odometer data (only appeared recently I have had the truck since march and used blue driver on it before I bought it)
u1075 Invalid engine oil temp
u1041 Vehicle Speed signal missing or incorrect (my speedometer is perfect verified with gps)
u1059 transmission position data invalid
The u1073 is likely an electrical connection issue. To track it down, a wiring diagram is needed. (AllData has a DIY subscription service, per vehicle, per year. It's not that expensive).
It could be a faulty harness (corrosion, for example), connector, or a power/ground issue. If you watch Eric O @ SMA or Ivan @ PHAD, the first thing they do is pull up the wiring diagram. Before assuming a faulty sensor, they will go over every piece of the electrical connection relevant to this sensor. Every relevant component is tested.
The process is exactly the same for a u1059, except that they're probing the connections and harness in the wiring path of the TCM (Transmission Control Module).
u1262 is really important because it's reporting a problem with the PCM. Again, either a harness, connector or wiring. If it's not that, then the PCM is bad.
A bad PCM might well spew out a bunch of codes, such as a VIN issue. Start with u1262 and go from there.
load test your battery + alternator
