Who knows about FCCC "MMDC" and its issues?
Gents, I've searched and read many issues regarding the old "VDC" units and the newer MMDC units. I'm thinking I may have developed an MMDC issue. Here's the scenario. We're presently on vacation and...
Forum Discussion
dougmac,
Well Sir, so far, I've done some tests that have indicated that the terminating resistors, each 120 ohms, are both intact and in good shape. But, based on the test procedures, when I test the correct pins in the diagnostic ports, on each end of the coach, I'm getting a "119-120" ohm reading on each end. According to the results I'm getting, the J1939 is OPEN. The readings I'm supposed to get from the two pins is 60 ohms. So, now it's simply going to be the painstaking, methodical tracing of the J1939 data link, all the way down the frame etc. The MMDC, and it's connections, pin testing etc. are all just fine.
Scott
Well Sir, so far, I've done some tests that have indicated that the terminating resistors, each 120 ohms, are both intact and in good shape. But, based on the test procedures, when I test the correct pins in the diagnostic ports, on each end of the coach, I'm getting a "119-120" ohm reading on each end. According to the results I'm getting, the J1939 is OPEN. The readings I'm supposed to get from the two pins is 60 ohms. So, now it's simply going to be the painstaking, methodical tracing of the J1939 data link, all the way down the frame etc. The MMDC, and it's connections, pin testing etc. are all just fine.
Scott
