Chrysler Repair: 98 Sebring intermittent reverse engagement, solenoid pack, trans fluid

Question
QUESTION: When starting the car and shifting from park to reverse, sometimes the transmission acts like it is in neutral.

However, we noted that the dashboard display has "R" highlighted.

Shifting into drive works and then back to reverse a few times has always got reverser working.  


I'm preparing to replace the prndl switch, but does the symptom of "R" correctly being shown on the dash rule this out?  

Thanks,

dick....

ANSWER: Hi Dick,
That switch is internal to the transmission and can be replaced, but it is not a simple part but rather is part of the valve body module. If you have a work-around you might delay dealing with this until the trans requires internal repair/rebuild. Check your trans fluid level and also assess whether the idle speed might be a bit low. Too low a pressure level im the hydraulic system of rhe trans is more plausible explanation.
Roland

---------- FOLLOW-UP ----------

QUESTION: Hi Roland,  I should be more precise.  When shifting from park to reverse normally I hear the solenoid pack clacking/buzz then the noise stops and the transmission is in reverse.

When the symptom occurs, (no reverse), the following occurs:
1. I start the engine and move shift lever from park to reverse.
2. No solenoid pack clacking/buzz is heard.
3. Dashboard display correctly shows the change from Park so that "R" is highlighted.  
4. I have revved the engine to ~3k with no change in the symptom.  (The transmission acts as if it is in neutral)
5. I have left the transmission in Reverse for about 5 - 10 seconds with the symptom continuing. (Acts like it is in neutral)  
6. Then when I shift to Drive, I hear the solenoid pack clatter/buzz.

Why would low pressure stop the solenoid pack from making noise in selecting reverse but not drive?

Also, since the computer sends the controls to the solenoid pack, isn't the computer deciding not to shift into reverse and not controlling the solenoid pack (since I can't hear it)

Thanks for the lightning quick reply!  I'm trying to figure out if it's possible for the prndl switch to be always good in terms of controlling the dashboard indicator, but bad in terms of getting the computer to shift into reverse?

Thanks,

dick....

Answer
Hi Dick,
You are welcome. The shift indicator is electrical, but the actual actuation of the transmission is mechanical/hydraulic and electrical and depends upon solenoids actuating valves and there being pressure at the correct level, etc. I am not saying you have no possible causes of this but rather the shift indication is purely electrical depending upon the position of the vertical shirg rod attached by cable to the shift lever in the cabin. So that switching is no doubt correct and rather the response to the switch is what is lacking. The exact causes are numerous, ranging from simple to rebuild and so I would decide at what point to take action other than living with it for now. The switch itself is unlikely to fix it. You could try a code readout (on-off-on-off-on and leave on, doing that in 5 seconds or less using the ignition key) then see if the mileage reading in the odometer window changes to show and 4-digit numbers preceded by a P). Let me know.
Roland