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2003 Transmission issues

2K views 16 replies 2 participants last post by  thecustommuffler 
#1 ·
Been a lurker, my first post. Run down on truck: 2003 Lariat, 6.0, full entire bulletproof at 9k miles, CC, 4x4, LB now at 19814.3 actual miles.

Truck has been taking off from a complete stop in second gear at times. Progressively over a few days got worse until it was constant yesterday. No trani codes in system. One of my guys cleared adaptive learn and test drove. All was fine. This am on way to shop trani felt weird 2-3,3-4 like not fully engaging. Then tow/haul started flashing. Toggle button and it felt as if something would engage/disengage. Pull over for restart and no more flashing tow/haul. Transmission shifted very strange. Pull into shop to scan entire system. P0730, P2703 codes with secondary codes of: P1876, B1359,B1318. I cleared trani codes but noticed I cannot clear secondary codes. I thought these secondary codes were there from an alt diode going out a couple weeks ago. Trnasmission fluid fine and clean. Changed filters (with tp roll) and fluid at 10k. Trani temp at idle holds 111. Thank you for your help
 
#7 ·
Fixed. I dont like 2-3 shift but might be a re-learn. One side of PHV was bad.Zero resistance zero continuity. I still, through schematics, cant understand how this affected 2 wd transmission operation unless values were off through 4wd control module. And I have a lil better brake pedal now.
 
#11 ·
P0730 means the transmission ratio was wrong. That doesn't give enough info to be useful, it can set in any gear. P2703 means friction element D (direct clutch) was too slow to apply. That can be due to a sticking solenoid or a problem inside the direct clutch.
 
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#12 ·
Thank you so much for your reply Mark. If you dont mind, concerning P1876 code, I`m looking more into 4wd control module due to the fact that I cannot clear this code. If you read my whole thread, am I correct to assume that would be my next focus if you will in relation to that code? I do understand that you arent actually seeing the vehicle so possibilities are large. Loading with fluid so road test soon with Empie dd solenoid and one set of fingers crossed. I really dont see how the direct clutch could be smoked in a reality of 8 total miles but toilet paper roll was black as night. Thanks
 
#13 ·
Drive test reviels yet again something different. Seems to now go through all the gears yet tow/haul flashing and its deffinately in tow/haul. Codes P0730 and P2703 both came back as well as now P0603 for KAM. Reset KAM. No P1876 in system now so its progress.
 
#14 · (Edited)
Mark, in the solus the Po730 code is for "direct clutch system failed OFF". Is this electrical instead of mechanical. Everytime I drive it its different. I`m thinking wire or module to include PCM at this point. I forgot to add that direct solenoid before changing was hot like 116 degrees. Then towards front of vehicle that row, the two outboard solenoids were hot as well but cooled down quickly with the key in off position.
 
#15 ·
That's not my understanding. P0730 I believe means that the gear ratio was incorrect at some point. It doesn't refer specifically to the direct clutch.

All PCMs have 4x4 capability. The 4x2 models should not have a wire connected to this pin. When in 4x4L this pin is grounded to tell the PCM that the transfer case is in low range. This modifies the shift schedules to work correctly in low range.
 
#17 ·
UPDATE: direct clutch is bad. Transmission shop said there is a very slight possibility that a bolt is loose. Dont remember what exact bolt he mentioned but,,,,making the call to Jasper with billet converter. With only 19k original miles on the odometer. It will never pay for me to get out of this truck.
 
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