dodge truck transmission issues limp mode (1 Viewer)

[2fpower]

Anyone have a resource that can help fix my truck? it goes into limp mode giving code P2769 that is low oil pressure. Lots of posts talk about being a ground issue on the transmission computer, but I can't find a decent thread to tell me where the darn computer is, let alone which wire to look at. What a pain.

 

[2fpower]

info dump....

Tests/Procedures:

1. The Cummins ECM normally sends out 12v to energize the transmission relay in the Totally Integrated Power Module (TIPM). To test, jumper B+ to the Yellow/Dark Blue wire at pin 10 in the C1 (gray 14-pin) TIPM connector.

2. The relay should then send out 12v on the Yellow/Orange wire at pin 9 in the C10 (gray 22-pin) connector at the TIPM.

3. Verify that the Yellow/Orange wire is not shorted to ground which would damage the the relay or TIPM.

You can also jump 12v straight to pin 9 in the C10 and clear the codes to see if they stay gone. Mine did.

 

[CrowleyFJ40]

What year? 2500?

 

[SammyT96LX450]

sent you a txt

 

[2fpower]

What year? 2500?

yes, 2004, 2500 Dodge cummins diesel with 48RE transmission

 

[CrowleyFJ40]

@2fpower Sent you a text with somthing to look at. Found various references to that connection being problematic, if yours has it.

In addition, here's another link with a very large PDF file all about Dodge transmissions. Looks like the 2004 diesel is completely controlled by the ECM, see page 15.
The TCC circuit appears to be controlled by the Transmission Speed Sensor (TSS) which shows to be located on the back left of the transmission. This link calls it the OSS, Output Speed Sensor. Pin 2 should be your ground for that circuit. Document says you need to check it using an oscilloscope, but I would think you could at least check for ground. Page 31 says it's for a 2006 and up, but might be the same for the pinout locations on yours to check continuity between the ECM and TSS/OSS.

On your ECM, on the left side of the engine, at the C1 connector, should be your ground for the ECM.

 

[CrowleyFJ40]

@2fpower Check out page 36 in the linked document above. Talks about a transmission that starts in 3rd and has troubleshooting steps for 2 scenarios (does upshift after start and doesn't upshift after start).

 

[2fpower]

Spent many hours working on this... way too many hours. Mad at every connector that Dodge makes. Every plug has some different mechanism with some different lock that all were full of crap and challenged my patience....

Pulled every plug on transmission and the main fusepanel/power control cluster -- cleaned and replaced. No real change. Then starting digging into @CrowleyFJ40 diagrams, got the pinout and wires for the Transmission case connector that appears to plug into internally the pressure sensor, and tried to check voltage and ground and came up with nothing. At that point decided this was beyond my repair abilities. Hopefully it is not the computer....

Sammy gave me the name of a transmission guy, so will call him this week.

 

[2fpower]

Called the source that @SammyT96LX450 gave me, great guy, is sending me pages of things to check.... so going to try this one more time...

 

[2fpower]

picked up the truck today... ended up being computer issue. I used a shop in lawrence called atsi. Guy was really honest and fair, and really busy, which to me is a sign of a good place to go.

The computer has a relay that grounds a wire to the tranny and it was not working. The shop made a relay to do the work and trick the computer, so all working again .....

Thanks @cjmoon