My car won't go into 4th gear overdrive

[boostedtsiawd]

I noticed when I'm driving on the highway my car won't shift into 4th which is overdrive but it does 1st 2nd and 3rd perfectly. I pressed the od button on and off and it does nothing but the button does light up what can it be? Where is the od sensor located on the transmission? Maybe it went bad?
1988 Nissan 200sx 3.0.

 

[OtisBlkR1]

id check that sensor... it would be exactly my first step.

 

[zzyzzx]

Check for codes.

 

[Nick1994]

Originally Posted By: zzyzzx
Check for codes.
You can have codes in a car that's almost 30 years old?

 

[eljefino]

It's more a solenoid than a sensor... good luck.

If you had an aisin warner transmission like in volvos and cressidas they go out all the time, but it seems you don't, but the premise is the same.

 

[Lolvoguy]

Originally Posted By: eljefino
It's more a solenoid than a sensor... good luck.

If you had an aisin warner transmission like in volvos and cressidas they go out all the time, but it seems you don't, but the premise is the same.


+1

also, check your fluid level

 

[Dave Sherman]

Might be a long shot, but is the engine getting up to normal temperature? I had a car that wouldn't lock the torque converter unless it was warmed up enough. Thermostat was opening too early or stuck open, and the torque converter would lock or unlock at odd times. Turns out it would warm up enough to lock going up hills or sitting in traffic, then get too cool going down hills.

 

[zzyzzx]

Originally Posted By: Nick1994
Originally Posted By: zzyzzx
Check for codes.
You can have codes in a car that's almost 30 years old?


I could do it on my 1985 Escort GT yes. Anyway, it's easy enough to set your multimeter on ohms and check all the transmission solenoid resistance.

 

[boostedtsiawd]

My speedometer doesnt work can this be the issue?

 

[eljefino]

Originally Posted By: boostedtsiawd
My speedometer doesnt work can this be the issue?


My god you nailed it!

Maybe you bumped its connector when you were under there deleting your catalytic converter a couple weeks ago.

 

[HerrStig]

Originally Posted By: Lolvoguy
Originally Posted By: eljefino
It's more a solenoid than a sensor... good luck.

If you had an aisin warner transmission like in volvos and cressidas they go out all the time, but it seems you don't, but the premise is the same.


+1

also, check your fluid level
+1

 

[boostedtsiawd]

No it never worked since i bought it a few months ago. Where is the speedometer cable/sensor located?

 

[Dave Sherman]

Probably an electric speedometer by 1988, and it would use the vehicle speed sensor data. No speed sensor data would explain malfunctioning transmission if the overdrive is electronic. Look around the transmission output shafts or the wheel spindles for a speed sensor. Could possibly be inside the transmission too.

 

[OtisBlkR1]

I had this same exact thing happen to a 90's eagle talon.. I was a broke dumb kid. I sold the car for next to nothing.. the guy that bought it replaced that part on the tranny and told me shortly after the car shifted and ran like a dream.. Ive kicked myself many times for that. It was probably worth $4,000 when I sold it for $600 bucks..

 

[NJC]

Originally Posted By: Dave Sherman
Might be a long shot, but is the engine getting up to normal temperature? I had a car that wouldn't lock the torque converter unless it was warmed up enough. Thermostat was opening too early or stuck open, and the torque converter would lock or unlock at odd times. Turns out it would warm up enough to lock going up hills or sitting in traffic, then get too cool going down hills.

+1. I've heard it happen on a few vehicles and it was the problem with my 1993 Accord.