Last night on my way back home my tranny started acting funny...it's as though it would go through the RPM range and up on the speedo without shifting...when I got onto the highway it would not go into overdrive (4th gear) for a long long time...I was at like 65-70 mph at like 2500 rpm and what not...I stayed at 65ish and then after a looonnnngg time the rpms dropped to around where they ahould be at 65 on the hwy when everthing is normal. There was like no normal progressive and predictable shifting in the tranny, not like normal operation how it shifts from a dead stop to 1-2 shift @ 12 mph, then another shift 2 - 3 at like 23 mph, then something *TQ lockup maybe?*at 36 mph...then a clunk at 40-45 mph where the rpms drop for highway speeds...but there was some slight bucking and surging here or there up at around 70ish mph as well,...

when the rpm dropped and I was in overdrive gear then I set the cruise control which worked up until my exit, then that died on me ...the cruise control dash indicator still stayed on but the pedals did not work, so even though the cruise says it's on, now I still was controlling everything with my feet as I'd do if I didn't have the cruise on. Just plain wierd!!!

This moring same kinda thing...on my way to work. Problems with the tranny not working like it's supposed to and the cruise control not working even though it's on???

I'm on smarty L3 with Stock injectors, itake, exhaust, FASS, and upgraded TC and VB... etc...my truck is a low mile (35K) vehicle and it's not modified heavily for power at all. At lunch I went out and I used the DTC funtion with the smarty and it gave me 3 codes:

1) P0122 Throttle Pos sensor voltage too low
2) P0602 ECM Fueling Claibration error
3) P1693 DTC cleared in companion JTEC module

what do I do from here? Please help...first diesel truck & it isn't running right and I'm worried

 

Start off by checking the trans fluid level. After reaching normal trans temp, idle it in neutral (set parking brake), shift through all the gear positions for a second or so, then leave in neutral with engine running. Check fluid. If it is low, then all sorts of goofy things happen. If it's not that you may check your battery connections (clean and reattach). Lastly, it may be your APPS. Do a search on that for more info....

 

Like sheriffav8r said, check fluid and connections first. Check the fluid in neutral with the brake set, use wheel chocks if you have to.
Don't worry about #2 and 3. #1 is the culprit. I would try an APPS reset after that. Do a search, it'll tell you how to do it.

 

When I got the TC and VB done at East Coast Diesel they put new tranny fluid in it...they are a professional shop with a good rep. I got that done in Sept of 2007 so the fluid should be very fresh and filled to the proper level I would think. Plus the truck only had 29k on it when they did the work...and it's got only around 35K on it now