1993 TrasSport 3.8L Quad Driver Codes 26 and 56

[tinkering]

Where the heck is the canister purge solenoid on this 3.8L?

[tinkering]

Originally Posted by Jeffrv

Proms seem to be quite robust, don't hear much problems with them as as a rule That being said, they can be damaged by electrical static discharge, critically important that you be thoroughly grounded to the PCM. They are also subject to physical damage while removing or installing, be careful doing that.
Did all these trouble codes show up all at once, or gradually one at a time over a period of time?

I think the codes would have to have appeared over time, not all at once.

[tinkering]

Originally Posted by tinkering

Where the heck is the canister purge solenoid on this 3.8L?

I found the canister purge solenoid on the 3.8L. It's at the back of the engine, just back of the intake manifold, and forward of the heater blower motor; pretty well in the centered left to right. I changed it out before with a new unit but no change to the codes.

I am procrastinating but I am going to have to check the wiring and connectors to
to the purge valve, EGR valve, and the transaxle harness (shift and TCC solenoids). Still don't have much energy after having covid and pneumonia...dang it..

[tinkering]

Can anybody tell me where the electrical connector for the shift solenoids is located on the outside of the transaxle?

[Blue Bowtie]

Follow the wiring harness and you will see the external connector right above the vacuum modulator.

http://www.wwdsltd.com/files/4T60ESideCoverRemoved.jpg

[tinkering]

Thanks for the picture Blue Bowtie.
6 wires in that transmission harness; brown, white, green, black, yellow, red.
Red goes to three solenoids that I can see. Would that make red a 12V supply, and the other colors the designated grounds from the PCM?
I see yellow, black, and green going to 3 solenoids.
What do the brown and white control?
I will search for a schematic in the service manual.

If I jumper A and B terminals on the diagnostic socket with the key on will I be able to check all of the grounds at the round connector above the modulator? I think I saw that in the manual?

Is it absolutely necessary to undo a frame member and lower the transaxle to remove the side cover? I would want to remove the minimal amount of stuff to get at those solenoids. If I have to change one solenoid I would like to change them all while I'm in there?

[tinkering]

Here is a very helpful trouble shooting youtube vid by scannerdanner.
https://youtu.be/kQz3g4HIWgs

[tinkering]

I am almost ready to bail on my 93 Transport.
This thread is old. I have come back to it a number of times over the years.
Those Quad Driver codes are the definition of irritation. I think I remember reading in the factory repair manual that these codes can come up due to bad transmission shift solenoids.
Anybody still working on their TSs?
This thread is pretty long too... and I am frustrated with that engine light and the associated poor running condition of this 3.8!
SHOULD I GIVE UP AND HAVE IT TOWED AWAY AFTER SO MANY YEARS?

Tech II said way back in the beginning of this thread that the ECM on those things are all prone to fail.
I tried a swap way back when, to no avail, with a unit from the wreckers. I transferred the PROM. The codes and symptoms did not change. It may have been a faulty wreckers unit.
I am considering throwing $200CAD for a replacement ECM from Rockauto. The GM remanufactured unit says, "Remanufactured; Local Programming Required", the Blue Streak brand says, "Plug n Play; No flash programming required." Which one to get?!

Should I go ahead with the tranny shift solenoid replacements before trying the replacement ECM? I bought the replacement solenoids a long time ago, haven't got around to doing the job.

I am so tired of working on this that I want to throw parts at it! STUBBORNNESS! Maybe I should just sell it or drive it to the wreckers? That would free up some tied up energy.

[tinkering]

WOW
I don't think I have ever received zero response to a post on AFs before!
Is there anybody there. This is a very viable thread still although it is very old.

[tinkering]

Maybe all my trans sport gurus have passed on?
New Blue Streak ECM will be here in a couple of days from RockAuto. I will try a switch out. I can still send the core back and only be out $135 CAD. It will be answered prayer if the light goes out.
I'm going to replace those transmission shift solenoids whether or not the new ECM clears the light/codes.