Hello....

I believe that I have read every thread associated with my problem and so far I have not be able to resolve it. My 2007 Fit Sport-Automatic with 195K miles, will not shift into 5th gear and sets the P0843 code. This happened suddenly with no transmission issues prior. I have:

1) Changed the transmission pressure switch - when this didn't fix it, I removed the new switch and tested it with air pressure and it works as it should
2) Replaced transmission oil filter
3) Dumped and refilled transmission oil twice - it did not look dirty the 1st time I dumped it. I usually dump the transmission fluid every other oil change or so - the magnet on the drain plug was perfectly clean
4) Fluid was low when I started and evidence of leak underneath - I believe it was coming from and improperly seated drain plug
5) On my 1st fluid dump and refill (bringing level up to normal) it worked perfectly for about 3 miles but when I turned around to come home it went back to not shifting into 5th and set a code
6) Other than this transmission is smooth as silk
7) There is evidence of rodents in the engine bay but I can't find any chewed wires - how do I thest the wire from the pressure swithch?

Does anyone have any other ideas?

Many Thanks In Advance

Dennis

 

Ok, I have done a little more research and believe:

1) Key on, engine off, the wire to the pressure sensor should have about 5 volts to ground
2) If it doesn't have voltage, then either the wire is broken somewhere or the PCM is faulty
3) If it does have 5 volts, then the switch (tested good with air pressure) is not getting enough pressure - clean fluid, new filter - does this mean the transmission is toast?

It is raining right now so I will test for voltage later today (I hope). I am trying to put pieces together to test actual oil pressure at the switch.

Thanks for any ideas

 

I wish you posted this at the main forum (gen1, GD3)
let's clarify few things:
this switch is located near firewall, not near radiator
the code per manual is for electrical problem only, so your transmission is good
failure of this switch causes transmission not to shift past 3rd gear ( about 3.5 k rpm at 42 mph)

step 17 calls for PCM "update"

 

Thank you, I​​​​​ was just about to give up and donate the car. I will test tonight and try to move this to the appropriate forum.

Thanks again.....
Dennis

 

Thanks so much....Took me awhile but I found it. Then took me a few minutes to figure out how to get to it. For anyone interested I:
1) removed battery and steel tray
2) moved trans oil filter out of the way
3) then switch is easy to remove
4) by this time my battery was disconnected so I did not check for voltage at the clip
5) removed switch
6) tested with air pressure - switch is bad
7) tomorrow I will confirm that wire is complete and that I have 5 volts

Question; is this switch the same part number as the one near the radiator? It is the same color.

Thanks Again

 

Yes in 2017 both switches (front and back) are the same parts as the switch on the back (which is , ironically, failed).
Should be brown , not orange https://www.fitfreak.net/forums/1st-...-switches.html
I've replaced one switch by radiator, then the firewall switch one year later
Best!