Hi guys. I got the code. But I can't even feel the car trying to shift in to OD. Also when I am at 60mph and hit the o/d button I don't feel it trying to shift down. Maybe I'm not going fast enough. It is at 2500 rpm at 65mph. Stock wheels and tires. What does your first gen read for rpms at this speed?

 

I just got a 99 durango slt. received the 3-4 shift error code. The O/D on-off button doesn't seem to do anything. Trying to figure out if it is actually engaging the o/d or not. Thank you in advance for your help.

Thank you.

Eric

 

the gearing for the rear diff would help to give you an idea of gears, as well as year/engine(transmission really),

but i will share mine

2002 4.7 w/ 545rfe and 4wd, 3.55 rear end, i turn about 1500 @ 65, and 2000 @ 80

 

Here part of a pdf file for your code P0753,If you need the rest.Just send me an email address to send it to.
TEST ACTION APPLICABILITY
919 Key On.
With the DRB, read trouble codes.
Is the Trans 12-volt Supply Relay Control Circuit code set?
All
Yes ® Refer to symptom P-1765 TRANSMISSION 12V SUPPLY RELAY
CONTROL CIRCUIT in the TRANSMISSION category.
No ® Go To 920
920 Key On.
With the DRB, read trouble codes.
Is the specific Good Trip displayed and equal to zero?
All
Yes ® Go To 921
No ® Go To 936
921 Road test Vehicle. Attain Vehicle speed of at least 50 MPH.
Push the OD Switch 4 times such that Vehicle attempts to shift from 3rd to 4th and
back.
Did the Vehicle shift between 3rd and 4th?
All
Yes ® Go To 936
No ® Go To 922
922 Key Off.
Disconnect the Transmission Solenoid Pack Connector.
Note: Check connectors - Clean/repair as necessary.
Key On.
With the DRB, actuate Trans Control Relay.
Using a Voltmeter, measure the voltage at the Transmission Relay Output Circuit.
Does the voltage fluctuate from 0 volt to over 10.0 volts?
All
Yes ® Go To 923
No ® Go To 933
923 Key Off.
Disconnect the Transmission Solenoid Pack Connector.
Note: Check connectors - Clean/repair as necessary.
Disconnect the PCM White Connector.
Note: Check connectors - Clean/repair as necessary.
Key On.
Using a Voltmeter, measure the voltage at the 3-4 Shift Solenoid Control Circuit.
Is the voltage above 10.0 volts?
All
Yes ® Go To 924
No ® Go To 925
924 Key Off.
Repair 3-4 Solenoid Control Circuit shorted to voltage.
Road test Vehicle. Attain Vehicle speed of at least 50 MPH.
Push OD Switch 4 times such that Vehicle attempts to shift from 3rd to 4th and back.
Did the Vehicle shift between 3rd and 4th?
All
Yes ® Test Complete.
No ® Replace the PCM.
Perform Powertrain Verification Test VER-5A.
346
TRANSMISSION
P-0753 TRANS 3-4 SHIFT SOLENOID/TRANS RELAY CIRCUITS —
Continued