'06 Saturn Vue Redline with Honda powertrain has torque converter problem

[atikovi]

This is a very clean 98,000 mile Saturn Vue Redline AWD with the 3.5L Honda drivetrain. Had it for over 2 years now and don’t want to sell it with the CEL going off every 200 miles for a torque converter code and someone thinking it needs a transmission.

The problem is that once the transmission warms up after maybe 20 miles on the highway, the torque converter has trouble staying locked up. Before, it would do 1,600 rpm at 60 mph. Afterwards, about 2,100 rpm. Not good for gas mileage and probably making the fluid hotter than it needs to be. It sets a P0741 code, TCC system stuck off. The repair manual gives this procedure:

Inspect for a mechanical failure of the TCC.

Inspect for a mechanical failure of the TCC PC solenoid valve.

Inspect for a mechanical failure of the TCC enable solenoid valve.

Inspect for a stuck lock-up shift valve.

Inspect for a stuck lock-up control valve.

Inspect for a stuck lock-up timing valve.

This is a diagram of the fluid flow,

This is the diagram of the solenoids,

I assume #1 is the TCC PC solenoid valve and #14 is the TCC enable solenoid valve? Where are the 3 later mentioned lock-up valves?

 

[JimPghPA]

Add to the list, it may be that dirty fluid does not allow that hydraulic system to work properly, and changing the fluid and filter MIGHT fix the problem.

 

[BMW Dom]

Add to the list, it may be that dirty fluid does not allow that hydraulic system to work properly, and changing the fluid and filter MIGHT fix the problem.

Definitely worth a try.

 

[atikovi]

Changing the fluid 3 times was the first thing I did. This ain't my first rodeo. No filter to change.

 

[ctechbob]

Sadly, you're probably in for either a repair bill, or dumping the car off. The torque converter probably needs to be replaced at a minimum, the maximum is a total rebuild. Once they start letting go, there's usually no amount of fluid changes or filter swaps that will walk them back from the edge. That's just the name of the game with the mid-2000's 5AT's until they started using the 4 shaft units, and even then there were sporadic torque converter problems.

Check to see if it is contaminating the fluid. If you already did a 3x D&F then it should still be nice and pink with no grey in it. If it's starting to come apart it will have all sorts of contamination in it.