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+--- Thread: Hour meter counts backwards (/showthread.php?tid=3)
Hour meter counts backwards - Austin - 01-03-2021
14M (B9J)
Customer noticed on VisionLink the hour meter would occasionally change to a lower number than the prior day. No pattern discernable on VisionLink - it may count up correctly for 5 days and then on the 6th day it would go down 3 hrs. Other times it would count back down daily.
Spoke with a (good) TC and he said he's never seen that before. He found no relevant DSNs or CPIs. He assumed Product Link was to blame.
Ran the machine while watching the Synchronize Service Hour Meter screen in ET. All ECMs had matching meters within a couple tenths. Eventually found that after keying-off and then restarting the engine, the Transmission ECM (which is the Master) would lower its meter. After a couple minutes, the other ECMs would sync to the lower meter. I let the engine idle for 0.3 more hours and repeated the key cycle. Once again, the Transmission ECM's meter lowered to what it was at the first key-on (0.3 hrs less). I verified all BAT+ and BAT- wires at the Transmission ECM had proper voltage.
Replaced the ECM and the problem was resolved.