P0700/P0755 Solenoid B DTC 2005 T&C van common fix?

After common uneventful trip to grocery store,
3.3L engine stalled when van came to a stop in parking spot,
before I shifted into park.
I just shifted into park and turned key off,
thinking “ maybe some water in gasoline from fill up yesterday.”

After shopping, got back in van, started engine, shifted into drive
and drove smoothly about 100 feet
when “Check Engine Light” came on while leaving store parking lot
and van automatic transmission seemed to go into “limp-In” mode with Park/Reverse/2nd gear only.

Drove back 12 miles slowly keeping engine rpms below 3500 and got home OK.
No odd noises.

Hooked up scanner and it showed 2 DTC codes set:

P0700 transaxle Control Module general fault

P0755 Shift Solenoid B

no other DTC’s or pending DTC’s

I had the scanner “Erase Codes”
then went for a drive but never got above 10 mph because
within 100 yards the “Check Engine Light” came on
and both P0700 and P0755 were back again.

122,471 mild driving miles, never any towing.
Transmission fluid is clear red with typical ATF+4 odor

Transmission dipstick has 2 holes “Cold” and 2 higher holes “Hot” for levels
and ATF level is slightly above the topmost hole marked “Hot”
measured in park with engine idling.

What is the typical fix
and further things to check?

Can a bad EATX relay cause this problem?

Solenoid pack,

VERY common ailment

Does this look like the part(s) needed?

https://www.amazon.com/APDTY-709211...hicleName=2005+Chrysler+Town+%26+Country

yes, but Ive not had the best of luck with the aftermkt version.

This is one part thats the Same as O2 sensors,,,,Ive learned the hard way. use OEM

as said, common problem.
however, check the plug very carefully for any problems, such as cracked insulation or broken wires.
i have found that several times over the years. not saying that will fix your problem.
just my experience. your mileage will vary.

Common problem
https://youtu.be/hz-NM4Tj2IQ

Amazon now says they have “lost” my next day delivery Solenoid Pack (was supposed to be Sunday by 5 pm) and are offering a refund.

One reviewer said Borg Warner is OEM to Chrysler.

Local Chrysler dealership says the Shift/Pressure Switch Assembly
is on Nationwide backorder
with the Stellantis computer saying “no date” for Estimated Time of Arrival.
No dealership shows one in stock within 150 miles.

Advance Auto/CarQuest had 2 non-Mopar parts at their local warehouse,
but their computer also said national backorder.
I bought one and they agreed to hold the second one until Friday at 5 pm.

$168
Solenoid SBE4945
S9863
UPC 1. 95580. 25265. 6

I got the old original Mopar one off just before 2 pm
when my day time relief ended her 5 hour shift
and I went back on solo caregiving duty.

The speed sensor removal requires a bigger diameter socket than an 7/8ths Oxygen Sensor specialty socket.
Luckily I had such a bigger specialty socket from an earlier job on the Ram,
maybe an oil sender specialty socket,
or a transmission temperature thermistor socket - can’t remember.

The 2005 FSM removal instructions for this part do not mention
that the thick and stiff main wire bundle in the engine compartment
blocks getting at the crucial 3rd long mounting bolt.

I had to unbolt 2 wire loom braces
(1) at the transmission dipstick, and
(2) below at the brace that bolts to the newly helicoil-ed filter access pan,
to be able to push the big stiff wire loom
upwards and toward the driver side enough
to get a socket on that third mounting bolt.

I had an extra thin 10 mm hand wrench that would go under the wire loom,
but this bolt is so long at nearly 4”
that the wire loom has to be moved somehow.

The removal job goes better if you have
as many as three socket extension bars either 4” or 6” long
to get at the 8 mm and 10 mm bolts.

The 16 year old gasket broke into many pieces as the part came off.

I tied a single edge razor blade to scrape old pieces off,
like the Rockauto video suggests,
but it is very hard to get a head light or flashlight to shine
on where you need to see to scrape effectively.
The side of the part toward the engine is round and fits into a mating round machined area,
making for more demanding old gasket bits removal.

Sharp edges on the sheet metal of the exhaust pipe shields
can lacerate your left forearm before you know it.

I ended up using blue painters tape to attach a penlight
to the shaft of my longest screwdriver
to get the last pieces of gasket off.

I had cleaned with brake cleaner all around this part like the Rockauto video suggests,
but I was still worried grit and dirt may have fallen into the 8 upward facing oil ports,
so I rigged a long pipe to a wet dry vacuum
and sucked at each open port hole.

I will start putting on
the new part on early in the morning.

working on a "bus" can be real "fun" at times, can't it ?
i'm glad you are making progress.
watch moving the wire harnesses. they can split the insulation on the individual wires if not handled carefully. heat causes the insulation to get hard, and when moved the wrong way, it splits.
this then causes moisture to enter, and the wire turns that lovely "green" color that can then cause one to tear hair out trying to find intermittent problems.
that is why there is no hair on the top of my head..............

Got up real early this morning to avoid rainstorms around noon.

After several attempts to get the part on just using the guide dowels to hold the gasket from falling downward,
I decided to Loctite Superglue the gasket on with tiny dots of glue on inside edges and pads.
This helped a lot.

As with removal, the fat wire bundle was the main enemy,
but loosening the two braces mentioned in the previous post allowed pulling the bundle up and right,
to get the part in from the underside.

A lot of wiggling was needed to get the 3 long mounting bolts to begin to thread.

The leftmost bolt seemed to take forever to tighten,
perhaps because it was pressing in the longest guide dowel.

The sight of torque wrenching two of the three bolts to 10 foot-lbs
using 4 wobbly socket extensions below the beam torque wrench did not look very “pro.”

The leftmost bolt I could not get the torque wrench on,
due to the exhaust pipe and its skin ripping heat shield,
so I pressed 20 lbs with two fingers on a scale for weighing airline bags,
then tried to duplicate that pushing sensation on a six inch handle wrench on the leftmost bolt.

Nothing leaked ATF,
neither the new Shift/Pressure Switch Assembly part,
or the helicoil-ed pan with a traditional gasket.

During the test drive all gears engaged as normal,
and afterwards my OBD-II Scanner
had no DTC’s
or pending DTC’s set,
but time will tell.

I worried each and every time I moved that hateful blacktaped wire bundle.
The Black Mamba of auto repair....

It seems Neons and Sebrings do not have the cursed wire bundle hindering the part like the 2005 T&C has.

hopefully, your repair will hold, and all will be right with the world !

Why has this part been failure prone for so long - some say since year 1988?

Does the electrical wiring in the solenoid fail by opening up, or shorting to ground?

Does the hydraulic valves the A & B solenoids push and/or pull on mechanically jam,
or does a steel valve stem break after so many cycles?

One Youtube video of this part on a Neon
claims that an internal, non-servceable gasket begins leaking large amounts of ATF
behind the sealed side door with 6 bolts that has the warning label:
“Do Not Remove or Shift Calibration will be Affected”

I did not notice ATF leaking from this part,
but perhaps it was,
and I was fooled from looking closely
by the ATF leaks further below from the stripped bolts of the trans pan?

Think of it as a fuel injector, on the mechanical side.
How many fuel injectors last almost forever while some do not. Look at the reasons for bad/failed injectors.

Then add the fact there are pressure switches inside. They have springs, diaphragms, etc.

Add the fact that they attract magnetic debris from trans wear.

Surprisingly many last for decades.

My guess now is that my “bad part” seems to have the wire coil of Pin 8 broken, this is called the “2/4 Solenoid

My DTC was P0755 “Solenoid B”

P0750 is Solenoid A

Page 325 of the
2005 T&C van Transmission Diagnostic Procedures Manual
has the connector Pin Outs for the connector of the Transmission Solenoid/Pressure Switch assembly,
or TS/PSA for short

Page 326 is the schematic of all wires to/from Powertrain Control Module to connectors

For the connectors to the TS/PSA

Pin 4 is the common ground

Pins 5, 6, 7, 8 are wires leading to coils of solenoids where the coil completes a circuit to Pin 4 (Ground)

Pins 5. 6. 7 do show continuity across those coils to Pin 4 (Ground) so I guess those wires still good

Pin 8 is labelled 2/4 Solenoid Control

On my “bad” part:
Pin 8 DOES NOT show continuity to Pin 4 ( Ground) so perhaps a wire is broke/burnt in two

Pins
1. 2/4 Pressure switch Sense
2. L/R Pressure Switch Sense
3 OD/ Pressure Switch Sense
are switches shown in schematic on page 326 as normally open.

None show continuity to ground at Pin 4, as you would expect if those switch are normally open

I believe the Trans Simulator checks for opens.

Almost every step mentioned in the Transmission Diagnostic Procedures Manual
requires an official Chrysler DRB-III scanner.

Is there an aftermarket OBD-II scanner that can duplicate what the DRB-III does?

Is the DRB-III now obsolete, and Chrysler using another newer model?

Went from DRB to StarScan to wiTECH.

Regarding the solenoid module, the diagnostic tool duty cycles the solenoids, checks for pressure responses, etc.