In service information for the P0741 code, the first thing listed after verifying the code comes right back which it does in your case, The testing section in diagram 2 below is for a more intermittent type of fault but it sounds like the problem happens right away, you should still do a visual check of the wiring to the transmission for any broken or damaged wires, corroded connectors, etc. There is a 16 pin connector you will see at the rear of the transmission housing.(Diagram 10).
Then the next step is they have you run a transmission line pressure test (Starting at Diagrams 3-8 below), which is what would be done in many cases for transmission codes.
Some possible faults are also listed, But if there are no wiring issues found external to the transmission, it would be important to do a line pressure test to make sure there is adequate pressure in the transmission, the pressure can range from 45psi to 300psi,
Even though the code is a a torque converter clutch pressure code, there are too many other possibilities to just change the solenoid out.
A line pressure gauge taps into a side port on the transmission, so there's not much of having to take anything apart for the test,
They have you bi-directionally control the transmission line pressure with a scan tool which will help to reduce the fluid from overheating.
The manufacturer wants the line pressure test done 3 times in Park or Neutral. You will need a capable scan tool that has this pressure increase and decrease function to run this test. But it is the correct way to check the transmission, if there's low line pressure, diagram 9 goes on to list High- or Low-pressure causes,
There is a section for testing the resistance of each solenoid, but I spoke too soon on checking the resistance of the lock up solenoid being that is it part of the valve body, it's not something that can be done from the main electrical connector of the transmission, it looks like there is even a procedure for removing and reinstalling the electrical connector sleeve that runs to the valve body. This is something I would recommend a shop doing since it is a complex setup, And the Reset Transmission Adapts procedure needs to be done as well so the control module can relearn each shift pressure value.
Sorry for the delay, there was a lot of service information to go through.
Images (Click to make bigger)
Monday, December 9th, 2024 AT 11:27 AM