robp823 Posted November 3, 2008 Share Posted November 3, 2008 have a 4r1100 that wont shift into overdrive pulled a dtc for trans overtemp and a p0783 3-4 shift error fluid looks brand new and and was at correct level. overdrive light blinks on and off fluid also does not smell burnt not really good with trannies any help would be great Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted November 4, 2008 Share Posted November 4, 2008 My best recommendation is to follow the transmission drive cycle instructions in the WSM... This will help determine what might be affected inside the trans... especially regarding friction elements... Might be a nice idea to let us know what we are working on, how many miles, service history.... I sense that you are young and have yet to see that the devil is, indeed, in the details. It is important to perform the drive cycle test religiously.... It is designed to test all of the friction elements in the transmission.... something that can be valuable when we start to open the transmission up... You should also have checked the pressures (look under "special testing")... at this point in time (and with this trans), I wouldn't get too enthralled with the overtemp code.... this has a much better chance of being a symptom than anything else. You will more than likely find that the shift error code wont get you much mileage, either. The PPT will have you jump through some hoops.... But you can "down and dirty" test the solenoids by unplugging the PCM and, with the key on, ground the appropriate pins at the PCM connector... Listen for a sharp click from the trans indicating that a solenoid has moved.... Voila - you have load tested the circuit and verified that the pintle in the solenoid responds. At this point you can likely forget any more electrical testing and be directed to refer to the symptom charts (making the drive cycle test more important). If you need a copy of the friction application chart, let me know.... There is one place that has an online set of powerflow charts (toolcrib.ca) but the 4R100/E4OD isn't on their list. I usually like to grab a snapshot or two on the IDS.... be sure to include GEAR, GEAR_RAT, TRAN_RAT and any speed sensor PIDS along with any other data you desire. These MAY be valuable in your diag but will be tough to get once you have started opening the trans up.... GEAR is the gear commanded by the PCM, GEAR_RAT is the computed total transmission ratio the PCM expects to see and TRAN_RAT is the total trans ratio that the PCM computes - this will help indicate any slipping friction members. With all of your info in hand, it is now time to get a bit more intrusive.... Drop the pan - pray for shrapnel - makes it easier to sell an off the shelf rebuilt.... If you go into a trans with any kind of miles on it with the idea that you are going to be a hero and save the customer some serious coin - you have a very real chance of marrying this transmission.... If you get to the point where you need to do some air testing.... you will find that some WSMs don't show where you need to blow.... and the 4R100 doesn't use test plates like some others..... No fear.... look at a WSM that covers the E4OD... these usually show the places to stick your blow gun. Automatics are actually fun to diagnose.... kinda like playing one of those detective computer games... think "applied logic". Quote Link to comment Share on other sites More sharing options...
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