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downshifting from 3rd gear issue with auto

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Hi, I'm new and wanted to say I'm grateful for such knowledge that I have been reading on here.  So I have a weird issue I need help with.. I have an 01 with a stage 5 trans and it is out of warranty but still functioning fine. I recently replaced my trans cooler and ever since I have been have a issue with the truck downshifting from 3rd gear to 1st when I come to a stop light or sign. I have the upgraded GM gov pressure solenoid and have replaced it along with the transducer and no change. Changed fluid and filter no change. Pulled my alternator fuse, no change. The only other symptom is the truck will want to start out in 3rd gear until trans fluid is warm. Also replaced rear axle speed sensor, and oss and the brake pedal switch . Only code I have is p1693 and don't have access to a hightec scanner. Any help is appreciated

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P1693 is error detected in the ecm.

I would check and clean all grounds just to be safe but it seems that there is a error in communication between ecm and pcm. The pcm is not getting the proper information from the ecm causing trans shifting issues. Someone else chime in and correct me if I'm wrong.

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7 hours ago, CumminsTech said:

P1693 is error detected in the ecm.

I would check and clean all grounds just to be safe but it seems that there is a error in communication between ecm and pcm. The pcm is not getting the proper information from the ecm causing trans shifting issues. Someone else chime in and correct me if I'm wrong.

 

Becareful... P1693 code could be an error in either ECM and/or PCM. So your going to need a actual OBDII code reader. I bought a OBDLink for cheap and use it with my tablet works very well.

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Thank you for the info. So I purchased a scanner and it gave me 0121 & 0122 prob from adjusting the new apps I installed. I cleared the codes nothing has come back. Truck still having same downshift issue from 3rd.  I also checked the TV Cable and it wasnt out if parameters. Could it be the tcc/ overdrive solenoids? And is there a way to test the tcc solenoid? Thank you all in advanced for the support 

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