I'm new here and looking for some advice. My wife's car has been shuttering and stalling for a week or so when she comes to a stop. I was trying to get it to the dealership this weekend to get it checked out but it didn't make it. Last night going down the road it completely lost all gears and the engine light came on. The codes were PO700 and PO870. The PO870 code said "transmission fluid pressure sensor". Fluid looks good and has no burnt smell. Once earlier in the week it would start off only in second gear and had no overdrive. I shut the motor down, cranked it up again and gears shifted fine again. Any ideas are appreciated.

 

This was in the Ram truck section. Moving it to the Durango section

 

Sorry and thank you

 

What size engine do you have? I would clean the throttle body and replace the plugs if they have 30,000 miles on them,
FF

 

Thanks for replying. It has the 5.7L and I changed the plugs about 5000 miles ago. It runs great. Just got a call the code PO944 popped up with "stuck or sticking main reg valve", "trans oil pump", "loss of hydraulic prime" and several other descriptions which basically sounds like it's saying there is no oil pressure in the trans.

 

Check the transmission fluid while in neutral and at operating temperature,
FF

Further reading from another site:

The Loss of Prime Test is used to prevent transmission defaults and erroneous fault codes during temporary loss of pump prime that may occur with low transmission fluid under severe braking conditions, start-up, etc. and to point towards more subtle problems such as a plugged or ruptured oil filter. The Loss of Prime fault is set by a loss of hydraulic pressure in the transmission system. This condition, if sustained, will result in the vehicle being unable to move.

• When Monitored: Every 350 ms
• Set Condition: If the transmission begins to slip in any forward gear, and the pressure switch or switches that should be closed for a given gear are open, a loss of prime test begins. All available elements (in 1st gear LR, 2/4 and OD, in 2nd, 3rd, and 4th gear 2/4 and OD) are turned on by the PCM to see if pump prime exists. The code is set if none of the pressure switches respond. The PCM will continue to run the loss of prime test until pump pressure returns. The vehicle will not move or the transmission will slip. Normal operation will continue if pump prime returns.

Possible Causes
LOW TRANSMISSION FLUID LEVEL
SHIFT LEVER POSITION
PLUGGED TRANSMISSION FILTER
TRANSMISSION OIL PUMP


Here is another thread about the trouble code P0700:

https://dodgeforum.com/forum/3rd-gen...ode-p0700.html

FF

 

Thanks again for the info. I'm having the filters replaced now to eliminate that option. Fingers crossed hoping it will work.

 

Jona:

What year is your D?

I concur that your trans sump filter may not be properly attached the trans inside the pan.

IIRC, they had some issues from the factory with this, and put out a TSB regarding it.

If your trans has not been serviced in the last 30-40K, a drain and refill with Mopar or Valvoline ATF+4 with a new sump and spin on return filter could not hurt.

Don

 

Good news. Turns out that's exactly what happened. The tube end of the filter had popped out, thereby causing no supply for the trans fluid. I've never seen that happen before but thankfully it works like new again. Thanks again to you guys for the advice. Sometimes the more simple repair works out.

 

Jona:

Very glad we could be of assistance!! Thank YOU for coming back and passing the good news back this way, and confirming that were thinking along the correct lines.

Don't be a stranger, and as I like to say PAY IT FORWARD!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Don