2001 4r70w Hard Shift Blinking Od Light - Diesel Forum

ohiobigdog · 08-23-2009, 10:44 AM

well i have a 2001 with 80k miles noticed slip about 65mph but if you pushed in od button to off every thing ok just not overdrive . so i took to tranny shop to have scanned showed 4 codes p0741,p1728,p1744,p0783 they said might be tcc solenoid so i dropped pan put new one in now the od light blinks cant just shut od off and it shifts as hard as my race car no slipping just solid shift any help greatly app.

Super_Dave · 08-23-2009, 10:45 AM

How did you get a 4R70 with a 7.3 PSD? Or is this on a different engine?

ohiobigdog · 08-23-2009, 10:51 AM

yes its a gas eng.

just found you guys seem to know what your talking about and im pulling my hair out

GrampyJim · 08-23-2009, 12:40 PM

Your codes are indicating that a lot more than just you torque converter is slipping... your P0783 is even indicating some sort of 3-4 error.... I am going to hang my hat on some kind of slipping friction element... You might be able to isolate the concern by using a decent scan tool and watching two PIDs... GEAR_RAT (the PCM/TCM knows the ratios built into the trans and will display the gear ratio for the commanded gear) and TRAN_RAT (the TCM can compute the real time gear ratio through the transmission taking into account any slipping friction elements). TRAN_RAT and GEAR_RAT should be lock-step.

ohiobigdog · 08-24-2009, 05:37 PM

any one else?

Mark Kovalsky · 08-24-2009, 09:11 PM

Since you didn't seem to like Grampy Jim's suggestion, I'll try something different that's simpler.

It's broke. Take it to someone that knows how to fix transmissions. He told you exactly how to diagnose what's wrong.