Came back from out of town and truck dash lit up with a wrench symbol and engine symbol. Used my dash daq to read codes. Codes that came up were p0703 p0791 p0793 p1000. I reset codes and drove it. Wrench light came on but no engine light this time. Read codes p0791 and p0793 only now. I cleaned passenger battery terminal which had a lot of corrosion. Reset and drove again. Same p0791 and p0793 come up again. I checked voltage at batteries with truck running. I read 14.1 vdc and .030 vac. Any suggestions?
Note: truck was parked for 4 days while out of town. Before I left no issues. After returning back home (drove daughters car on trip) issues started. Truck has been tuned for at least 6 yrs.

 

Here is the info for your codes

 

I downloaded info for codes from site. But don't know where test point 1 is at. Saw video on YouTube to check for voltage at harness. Fixing to check, supposed to have 12v on one wire, 5v on another and the last is to be ground. Will report findings if I can get to plug.

 

Ok well went under truck to check voltage on wiring to sensors. Had truck off but key to on position. On wiring to sensor 7m101 (auto trans speed sensor) I read 4.9v,4.9v,0v,11.8v. On wiring to sensor 7h103 (Trans speed sensor) I read 0v,0v,0v.

 

Here is the pinpoint test

 

Thanks for pinpoint test.

On test 1 I don't have a scan tool to access transmission PIDs

Skipped test 2 due to no scan tool

test 3 "

test 4 "

test 5 voltage checked out ok

test 6 need help locating tcm so I can perform test.

test 7 3pin plug=1 ohm,7.4k ohms,3.2meg ohms
4pin plug=9.25k ohms, 9.26k ohms, .8 ohms, 2.5meg ohms
Readings don't pass test 7. Could not find any shorts. Was wondering if the pins with on both plugs with less than one ohm would be due to wires being ground

test 8 having a hard time reaching sensors in place to test

 

Note: codes p0703 and p1000 came back up along with p0791 and p0793

 

TCM should be mounted on the frame around the transfer case on the driver side. P1000 sets every time the pcm DTCs are cleared. P0703 is your brake pressure switch. Look at the connector to the switch (on brake master cylinder) and the C140 connector for poor contacts. I have to run now and will be in Houston all day so I will post the pinpoint for P0703 later when I return if you need it.

 

pinpoint for p0703

 

Update: replacing Trans sensor closest to engine solved issues. No more codes. Replaced weeks ago just have not had time to update post.

Thanks kloss for help.

 

Awesome! Glad it was resolved.