Torque converter & Shift Solenoid B

[Tupana]

I had an emission test done recently on my 99' Aurora and it failed because the SES light was on and after the DYNO test it found these two results P0741 - Torque converter clutch circuit performance or Stuck off and P0758 Shift Solenoid B Electrical . Im up a creek right know without any knowledge of what or how to fix these. Can I get a little guidance please

[aurorabrain]

To fix these problems and find out whether or not you have a mechanical or electrical problem you need a multimeter and a scan tool. Shift solenoids are 20 ohms resistance when good, and the TCC cluch performance is a test you can do while driving with a scan tool, you are going to view TCC slip and note if it is within spec. To elaborate any more would be worthless if you don't know what i'm talking about. If you want help, PM me.

[parts68]

ck the TCC by going 50 mph in OD and tap lightly on the brake pedal.
If RPM goes up then back down the TCC is disengaging and re engaging.
you dont mention what yr it is.

[Tupana]

OK I will give that a try.

[aurorabrain]

I'm wondering what that would have to do with it not passing emissions?

[parts68]

anytime theres a check engine light or service engine soon,the inspector is told to flunk it.
Funny , one would think that a tranny problem is not emmision related but it is.
The car was passed when new by doing a driving "loop". When driving in that loop all
things that contribute to driveability and emmisions are tested. Now that the car is a few years
old, some things that helped the car when new pass that emmision standard,are not 100%.

[TJM]

I have been battling the P0741 code for about 6 months I think and here is what I've learned.

First off - check this Thread:
www.aurorah.proboards47.com/index.cgi?board=1stgen&action=display&thread=1139410359

And now for the update:

I think the Lubeguard stuff has been a lifesaver - er, tranny saver. (be sure to use the right type of Lubeguard)

After the initial treatment with Lubeguard I did notice SOME improvement. However, the SES would still be ON more than off.

In an act of desperation, I used a turkey baster to remove enough tranny fluid to make room for a 2nd bottle of Lubeguard. The results of the 2nd bottle were not immediate but over the next 2 weeks the SES light went off and remained off for weeks.

A few other things I have noticed regarding P0741. Keep your tires hard; like 34 psi, and keep it in the AC mode all the time.

The hard tires will help the car roll better and put less stress on the TCC, helping it to stay engaged.

Keeping the AC on is tougher to explain, but I think the values that the PCM uses to set the SES light for this code change when the added load of the AC compressor is considered.

I also tend to use 3rd gear when in traffic and while accelerating up to 65 mph (I think it helps circulate the Lubeguard through the TCC valve with less stress)

Use cruise control less and baby the accelerator to help keep the TCC engaged.

All the above keeps the SES light off for 90% of my driving. AWESOME!

Maybe Lubeguard can help the solenoid issue as well.

In addition, my local dealer (Massachusetts) says that the dyno only brings the speed up to about 35 mph so the TCC never has a chance to engage. He says as long as the code is cleared before the inspection, the car should pass. Also, from what I have read, P0741 is a "B" code and B codes are emission codes that will fail an inspection.

[Tupana]

Hey TJM, Thanks! I will go out and purchase some of that LUBEGARD. Did you first have your transmission fluid changed, then add. I only ask, because I know I need to have mine changed. Do you recommend any particular transmission fluid?

[TJM]

I had my fuid flushed and changed at the dealer before adding the Lubeguard. I found the Lubeguard at CarQuest auto parts. Like i said, be sure you buy the right one; there are 3 different types. Check the link in the other thread.

Recommend oem fluid and filter.

Also - I'm not sure but once the pan is off I think you may be able to replace the 2 shift solenoids from there at the same time as the filter. Another ACNA member will know for sure.

[parts68]

yes its pretty easy to change the shift solenoids when pan is off.
You will need to drop the valve body tho.
I have 2 new shift solenoids with filter and bolt for $30 shipped in USA.