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you did not ask a question, why is that? just a code.
which trans, regular or CVT? there are 3 transmissions. and m/t
the Trans chapter shows 7 trans. and 4wd options.???
VIN code A,C or G? (tranny code is in VIN)????
p2 is a factory only code.
Downshift Switch Circuit Low
are asking how to do all the FSM steps. to diagnose this.?
you reset it and it came back
are there driving symptoms??????????
the set is. P2779 Downshift Switch Circuit Range/Performance
P2780 Downshift Switch Circuit Low
P2781 Downshift Switch Circuit High
P2782 Downshift Switch Circuit Intermittent/Erratic
the key to understanding the cause is to understand the test.
how is the test done, (monitors) and what does it actually measure.
a real fsm will tell you if the LOW means, voltage at solenoid is low.
or RPM was too low.
and is key to the cause.
i dont have the real FSM, and online shows nothing.
There's no such thing as a downshift relay.Trans downshift is cable actuated.Go to the end of cable at the carb/throttle body,open the throttle fully by hand and depress the black button in the cable connection block,the cable housing will pop and when your driving will automatically reset to where it needs to be.Your done.
there is no vacuum line for reverse. the transmission uses fluid and silanoids inside for reverse. if reverse isn't working the low/reverse band is blown. you can test it by driving and manually downshifting into 1 and if it downshifts through all gears but wont downshift into 1st (feel the truck slowing down from engine braking) then your band is broken. time for a trans rebuld
From what you say Daniel, your kickdown cable need's to be adjusted, here's how :
Down at the pressure lever on the front of the trans, loosen off the cable
retaining nuts so there is a little slack in the cable. then start taking the
slack out of the cable a little bit at a time; Rest a long screwdriver on the
end of the pressure lever, holding the screwdriver with one hand start opening
the throttle with your other hand.
Just at the point the idle RPM barely
rises, the pressure lever should just barely move.
Driving test; Going
along a level road at 25 mph light throttle, floor the gas pedal. The trans
should downshift to first gear.
repeat the same drive at 28 mph, floor
the gas pedal, the trans only downshifts to second gear.
You dont want to start buying 250 dollar parts , that you dont know you need.You need to hook a scan tool to this thing and see if the downshift is even being comanded. When you come to a stop the scan should have 0 output rpms and should say the trans is in low gear.If you have say 14 rpms showing on the output speed sensor at a stop the the computer will think the vehicle is still moving and not allow for a downshift.This trans does not have govenor solenoid and sensor like the earlier jeeps did.Its electronic controls are more like the mini vans with the 604 trans. I have seen mini vans have a downshift bump and / or no downshift because the plugs wires were too close to the wiring harness and creating a falseoutput speed signal. It will pay to have this Transmission diagnosed by someone with knowledge and the tools.
most cars including yours, you have a speed snesor on the gearbox, which tells the computer (ecu) and transmission how fast you are going....the fact that you have included that the speedo is erratic, is telling me that the sensor needs to be replaced, as it is telling the ecu (which tells the speedo) the incorrect signal as well as the transmission......hopefully, easy fix
this reminds me that cars are like humans IN A WAY, the same symptoms may lead to a cause, the car not downshifting and the erratic speedo are the symtoms, just like a runny nose and cough are symptoms, and the sensor is the cause of the faults, where the cold is the cause of the faults in us....how cool