1986 Honda Prelude - Automatic transmission won't shift into overdrive.

Shift - interlock system problem .
Automatic Transmission Shift Lock Control System
The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the engine is running. The driver must press the brake pedal before moving the shift lever out of PARK position. The system consists of the following components:
• The automatic transmission shift lock control solenoid
• The automatic transmission park lock solenoid
• The automatic transmission shift lock control switch
• The transmission range switch
With the ignition in the ON position, battery voltage is supplied to the automatic transmission shift lock control switch. The circuit continues through the normally-closed switch to the automatic transmission shift lock control solenoid. The transmission range switch provides a path to ground for the automatic transmission shift lock control solenoid in the PARK position. With the automatic transmission shift lock control solenoid energized the shift lever is mechanically locked in the PARK position. When the driver presses the brake pedal, the contacts in the automatic transmission shift lock control switch open, de-energizing the automatic transmission shift lock control solenoid. This allows the shift lever to move from the PARK position. When the shift lever is out of the PARK position the controlled ground contacts in the transmission range switch open. This prevents the automatic transmission shift lock solenoid from energizing when the vehicle is out of the PARK position.

Have you tried shifting the automatic transmission to neutral, or if manual transmission- place shift lever to neutral position, then shift the transfer case to neutral position wait a couple seconds then try shifting to 4 low- if you have manual hubs, engage those last. This removes most of the potential mechanical resistance that should allow for the transfer case to shift.

If it still will not go into 4 low you may be dealing with damaged teeth, bent shift dog or worn internal bearings inside the transfer case. As I recall, that was NOT a shift on the fly transfer case.

For Automatic transmission problem,click the link below:----Overdrive light in the dash blinks? http://repairhelpcenter.blogspot.com/2012/01/overdrive-light-in-dash-blinks.html
--------- Automatic transmission troubleshooting:----

http://howtobyme.blogspot.com/2011/11/automatic-transmission-will-not-go-into.html

---------
Automatic transmission shift lever issues?-------

http://technoanswers.blogspot.com/2012/01/automatic-transmission-shift-lever-hard.html

-----------
AUTOMATIC TRANSMISSION FLUID LEVEL? --

http://schematicsdiagram.blogspot.com/2011/07/how-to-check-automatic-transmission.html

--------------

AUTOMATIC TRANSMISSION FLUID AND FILTER?

http://schematicsdiagram.blogspot.com/2011/07/how-to-change-automatic-transmission.html

-----------
Transmission fault light on car dash?

http://schematicsdiagram.blogspot.com/2011/12/transmission-fault-light-on-car-dash.html

--------
Transmission shifting problem?

http://schematicsdiagram.blogspot.com/2012/01/transmission-shifting-problem-on-toyota.html

--------
Transmission Slips out of 2nd gear?

http://repairhelpcenter.blogspot.in/2012/02/transmission-slips-out-of-2nd-gear.html

-----------
OD light flashing and transmission fluid leaking?

http://repairhelpcenter.blogspot.in/2012/02/od-light-flashing-and-transmission.html

----------
Why Transmission fluid leaks near radiator?

http://repairhelpcenter.blogspot.in/2012/02/transmission-fluid-leaks-near-radiator.html

----------
Transmission fluid leaking?

http://technoanswers.blogspot.in/2012/02/ford-windstar-transmission-fluid.html

-------------
****** wont go in reverse?

http://technoanswers.blogspot.in/2012/02/dodge-neon-wont-go-in-reverse.html

-------------
Automatic transmission will not go into reverse?

http://technoanswers.blogspot.in/2012/02/dodge-automatic-transmission-will-not.html

----------
Transmission is making buzzing noise?

http://technoanswers.blogspot.in/2012/02/transmission-is-making-buzzing-noise.html

-----------

This will help.

Thanks.

For Automatic transmission problem,Check the list of help links below.click the link below:----Automatic transmission troubleshooting:----

http://howtobyme.blogspot.com/2011/11/automatic-transmission-will-not-go-into.html

---------
Automatic transmission shift lever issues?-------

http://technoanswers.blogspot.com/2012/01/automatic-transmission-shift-lever-hard.html

-----------
AUTOMATIC TRANSMISSION FLUID LEVEL? --

http://schematicsdiagram.blogspot.com/2011/07/how-to-check-automatic-transmission.html

--------------

AUTOMATIC TRANSMISSION FLUID AND FILTER?

http://schematicsdiagram.blogspot.com/2011/07/how-to-change-automatic-transmission.html

-----------
Transmission fault light on car dash?

http://schematicsdiagram.blogspot.com/2011/12/transmission-fault-light-on-car-dash.html

--------
Transmission shifting problem?

http://schematicsdiagram.blogspot.com/2012/01/transmission-shifting-problem-on-toyota.html

--------
Transmission Slips out of 2nd gear?

http://repairhelpcenter.blogspot.in/2012/02/transmission-slips-out-of-2nd-gear.html

-----------
OD light flashing and transmission fluid leaking?

http://repairhelpcenter.blogspot.in/2012/02/od-light-flashing-and-transmission.html

----------
Why Transmission fluid leaks near radiator?

http://repairhelpcenter.blogspot.in/2012/02/transmission-fluid-leaks-near-radiator.html

----------
transmission fluid leaking?

http://technoanswers.blogspot.in/2012/02/ford-windstar-transmission-fluid.html

-------------
****** wont go in reverse?

http://technoanswers.blogspot.in/2012/02/dodge-neon-wont-go-in-reverse.html

-------------
Automatic transmission will not go into reverse?

http://technoanswers.blogspot.in/2012/02/dodge-automatic-transmission-will-not.html

----------
Transmission is making buzzing noise?

http://technoanswers.blogspot.in/2012/02/transmission-is-making-buzzing-noise.html

-----------

This will help.

Thanks.

Well, if it is doing all of that, the Check Engine light has GOT to be SCREAMING at you! Continuing to try to force the vehicle to operate under such conditions will only cause further damage to the vehicle. I would recommend getting the thing to where you can scan your onboard computer and find out what is going on.

There is a dipstick in the transmission down by the radiator. It is yellow in color. You add the fluid thru the dipstick hole. Check the fluid with the engine off.

you should have 2 bolts in the side of the trans the top one is the fill hole the bottom one is the drain hole .

First thing to do is check the fluid level if that ok you may want to think about having the transmission filter and fluid changed, there are other possibilities but check these first

have you checked your automatic shift linkage?

Honda transmissions,as well as most other overdrive transmissions,should be driven at all times in drive 4,or the overdrive position,with the exception of severe driving conditions,such as towing a load,extremely hilly terrain,or long uphill grades,the trans should be taken out of overdrive,and placed in the drive 3 position.This is to prevent the perpetual shifting back and forth of the trans from 3rd into 4th,back to 3rd,back to 4th,back to 3rd,that would eventually damage both the 3rd and 4th gear clutch discs and components.