Hello All, new here,

My 2005 Dodge Neon SE has been pretty good to me the last 5 years until the other day when it started popping in and out of gear. Then it felt like it was stuck in 2nd gear. Limp mode, I think it's called. The Engine light came on and the speedomter got wacky (0 when accelerating, 20-30 when letting off the gas)
This was temporary, and for a day it seemed to be driving fine with a careful rightfood and eye on the RPMs. But the following day the problem came back and hasnt gone away, leaving me practically immobile. Maybe once or twice I get lucky and it shifts into 3rd, but when I accelerate to gain speed, it always downshifts into 2nd.

Fluid level and color looks good. Probably due for a filter change and flush.

Engine error codes P0573 & P0700

So here is my question

1. How does engine error code P0573-BRAKE SWITCH #1 CIRCUIT HIGH effect my transmission? I dont think that this was an existing problem before the transmission started as there was never a check engine light on until the transmission started to act up.

2. I understand that P0700 could be telling me that there could be more problems if I scan the Transmission Control Module. Or it could mean that the module needs to be replaced. However, I have seen people posting similar problems on the web and are able to get more 0700 codes from the engine computer. So at what point did Dodge start this? Are there TCM for 2005s and later or all error codes stored in the same place?

3. The wacky speedomter - Output Speed Sensor?

4. To be honest, I want to stay away from an actual Transmission place due to some bad past experiences. Can regular auto repair mechanics check codes on a TCM and replace things like speed sensors, shift solenoids, or anything else transmission related that doesnt involve actually removing and opening up the trans?

Thank you in advance for any help you can give

 

2. The TCM is integrated into the PCM on NGC Neons (2003-2005). The codes come from the same place.
3. Possible. May be freaking the transmission out too.

I'd get an actual scanner and pull codes, in case that wasn't how they were pulled. I can't get into too much detail at the moment about the DTC's as I don't have access to the computer with the shop manuals on it.

 

thank you
P0573 went away, not sure how oe why

 

I read that code may just go away, and that it doesn't really affect anything. Something to do with cruise control I guess?

 

Well, those 2 codes were just flashes on the dashboard

Used an actual ODBII scanner and found 3 more. P0720 (output speed sensor), P0731, P0732.
Got the $17.00 sensor from Auto Zone...hear it's a easy replacement and also read somewhere that a faulty speed senor can trigger up to 7 other codes, so I am keeping my fingers crossed.

Despite the easy fix, it does concern me that there are no instructions to replace the Output Speed Sensor in the Dodge Neon Haynes repair manual. BUt I hear its a 30 minute job tops

 

Perhaps it is something they don't want a lot of people messing with? Remove old sensor, install gear onto new sensor with new o-ring and reinstall.

 

New sensor in. Speedometer totally not working...as oppose to being wacky. Could tell the old sensor was bad...the magnet/metal has split through the plastic end.
curious if Auto Zone gave me a wrong part

also, when removing my air filter housing, noticed that it was an old housing more relevant to 2002 and before neons...hmmm...

 

nope if the sensor fit, then then it's the right one. any chance you could have a bad wire or connector? did you pull on the wires as you tried to unclip the connector?

 

took it back to AutoZone. Now only P0700 and P0731 codes comes up. The speed sensor part # is fairly universal for Dodge transmissions, so I am sure its the right one. But if Speedometer is totally not working, shouldn't the P0720 code return on the diagnostic?

 

the bad connector could be the problem,...I don't think I pulled or damage the wires...there really isn't much tug room on that side of the transmission.