08 Escape U codes
It's a school project of mine and I'm a little stumped with it. It's an 08 Escape with a 2.3 and a 5 speed. The U Codes are:
U0255: Lost communication with front display interface module
U0256: Lost communication with front control interface module
I checked power and ground to the FDIM which were fine. I had source voltage at the power wire to and 33mV drop on the ground circuit of the module. I hooked a lab scope up to the network communication wires at the FDIM, the radio, and the heater controls. It seems the FCIM is in the radio. Regardless of whether I'm right or wrong abaout FCIM location, I found two more network wires to backprobe with a scope. I didn't have a technical reference for good or bad values so I checked all three to try and establish what normal might be. Every network wire I backprobed showed me that data travels on about two volts so I'm content that the FCIM and FDIM are talking the way they're suppose to. I know hooking my scope up doesn't tell me what's being said on the communication wires, but it did tell me they're talking to each other. I use alldata for my technical reference and I struggle like crazy with it. I don't know what I'm missing in information or my diagnostic strategy.
I almost forgot to mention, I had the luxury of using the Ford IDS scan tool and I was able to perform a test that commanded the display module to gradually light up over the course of five seconds. The display lit up fine and it seems like an exercise in chasing my own tail.
Would somebody have a better circuit diagram for the module network than I can find? Any ideas in what I'm doing wrong or what I need to do next would be appreciated.
Last edited by no_common_sens; 02-22-12 at 07:58 PM.
Reason: details details details