Mitchell Thomas Headen Posted July 9, 2015 Share Posted July 9, 2015 I've got codes 75,88 and 63. I know they have something to do with the data link between the ECU and the transmission. I was getting off of the interstate yesterday. The truck wouldn't downshift like it usually does. Then it wouldn't go into 2nd. I have a 99 cx613 with Eaton 10 speed auto. I think it's one of the first. I shut it off the clear the code and cycled the switch to restart it. It was flashing a F - code. I have it at Mack now after sitting on the ramp for 4 hours and a horrible tow bill 60 miles to Jville. I disconnected the batteries for 20 minutes and checked what I could. Still no go. Anybody have an idea what Mack is gonna tell me when they get to it, hopefully tomorrow? Engine is an E7, 427. Quote Link to comment https://www.bigmacktrucks.com/topic/40851-codes-8875-and-f-in-99-cx-613/ Share on other sites More sharing options...
turckster Posted July 11, 2015 Share Posted July 11, 2015 The 7-5 fault is VECU input voltage, 9-9 fault is Aux. Input device #2, can't find 8-8 fault. I suspect its a voltage issue to the VECU--anything from a bad fuse, bad battery connection, ground issue or ground relay, possible bad VECU and so forth. Hard to tell what it might be without my hands on it. Good luck Quote Link to comment https://www.bigmacktrucks.com/topic/40851-codes-8875-and-f-in-99-cx-613/#findComment-296294 Share on other sites More sharing options...
Mitchell Thomas Headen Posted July 13, 2015 Author Share Posted July 13, 2015 Thanks Turkster. Since I posted this Mack found that its a TCU. Transmission Control Unit. Its an expensive fix. I never knew so many signals ran thru these control units and were tied together. The VECU and EECU. Its absolutely maddening. They were getting one from Baltimore today and I hope i'm rolling tonight. Quote Link to comment https://www.bigmacktrucks.com/topic/40851-codes-8875-and-f-in-99-cx-613/#findComment-296541 Share on other sites More sharing options...
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