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muffinman 12-29-2013 09:54 AM

PO 841 code
My 2002 Overland sets off this code sometimes." High pressure switch A inhibited". When it does ,it goes in to limp mode. Turn it off and restart it and it shifts fine. After a bit the check engine light goes out. Is this pressure switch in the solenoid block on the top of the valve body?

Frango100 12-29-2013 11:10 AM

Re: PO 841 code
Did you check the fluid level first?
This code can be set when air enters the pump. Sometimes a split inlet filter or just low fluid level can be the problem.
The pressure switch which sets this code is indeed part of the TRS solenoid block which is mounted on top of the valve body.

muffinman 12-29-2013 11:59 AM

Re: PO 841 code
Fluid level is good. Filters were changed two years ago. Guess I can look at them. Old ones were ok.

Frango100 12-29-2013 12:25 PM

Re: PO 841 code
Have a look at the large electrical connector At the left side of the transmission. That is the one which connects directly to the solenoid block. Dirt, moisture or oxydized pins could also cause problems.

muffinman 12-30-2013 06:51 PM

Re: PO 841 code
Cleaned the connections, put a little dielectric grease on and she drove great, for about a day. Threw po841 again and went into limp mode. Turned it off restarted and she shifted fine. CEL went off about a hour later, strange. Might not do it again for a week or a few months. Or maybe in the morning. Does it throw a specific code when the TRS solenoid block needs replaced or does each switch/solenoid throw its on code?

Frango100 12-30-2013 07:30 PM

Re: PO 841 code
There is no specific code for the solenoid block, each switch or solenoid has its own failure code.
Have a look as well at the TCM connector. It has a central bolt which has to be loosened to get the connector of.
Eventhough it could be wiring, its a good change that the pressure switch is faulty. It has a rubber membrane, which actuates a brass plunjer under spring pressure. The rubber can tear. I asked once for the solenoid block seal plate, and received new springs and rubber membranes as well.
But most probably you could better change the solenoid block completely. A good address for this is:
Here is the block: Mopar 45RFE Solenoid Block - Oem New ! Save Here ! !
This is an updated solenoid block for 5-45RFE from 05 and on, which retrofits on the 99-04 5-45RFE. You will only also need to buy a new detent plate to make this work.
It could be a good idea to change the line pressure sensor at the same time. If over time the pressure settings of the sensor have changed, the transmission could regulate a too low line pressure, which could result in slipping clutches and premature wear.

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