Hello, what year, model, engine etc?
2005 Jeep Liberty Sport. V6 gasoline engine
The O/D stands for "over drive off" this means you may have hit the button on the shifter and turned OD off. This can be done by the driver so the trans does not go into 4th gear/overdrive. If the button is NOT turning it on/off, then a scanner needs to be hooked up via shop to locate the trouble area in the overdrive controls
OVERDRIVE SWITCHDESCRIPTION The overdrive OFF (control) switch is located in the shifter handle. The switch is a momentary contact device that signals the PCM to toggle current status of the overdrive function.OPERATION At key-on, fourth gear operation is allowed. Pressing the switch once causes the overdrive OFF mode to be entered and the overdrive OFF switch lamp to be illuminated. Pressing the switch a second time causes normal overdrive operation to be restored and the overdrive lamp to be turned off. The overdrive OFF mode defaults to ON after the ignition switch is cycled OFF and ON. The normal position for the control switch is the ON position. The switch must be in this position to energize the solenoids and allow upshifts to fourth gear. The control switch indicator light illuminates only when the overdrive switch is turned to the OFF position, or when illuminated by the transmission control module.
Where is the switch to overdrive turn and off?
You should have it on the shifter. I do not remember exact spot but there is a switch/button on the shifter that turns OD on/off