I was driving along in my 240,000 mile brick and it the overdrive kicked in and has stsyed on. Poor thing reved pretty high, scared the hell out of me. I have depressed the button on the shifter a number of times and still stays on. The light on the dashboard goes on and off when I do this but as I said no change.

Any suggestions.

Murky

I just had my auto tranny not shift from 3rd to 4th. Since I knew that the OD solenoid electrical circuit was sound, I pulled over and topped up the transmission fluid.

Shifting went back to normal. So check your tranny fluid level too.

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1990 244 DL

The OD operation is controlled by 5 components and the wiring that connects them—

1) Fuse 12 (fused voltage to #2, #3, #4, and #5)

2) The Shifter button/switch (turns OD relay off and on)

3) The OD relay (controls Upshift Arrow light and Solenoid (separate wires))

4) The Upshift Arrow light (ON means solenoid OFF)

5) The OD solenoid (Allows OD engagement when ON, the "default" Relay state at Key On)

Note to Murky: If the Shifter switch makes the Arrow light (#4) go on and off, then items 1, 2, and 3 are OK, and the problem is most likely the undercar wire to the Solenoid (#5) or the wire connector terminal at the solenoid.

Less likely would be be Solenoid itself.
Also possible (but very unlikely) would be the relay controlling the Arrow light (#4) correctly, but failing to activate the Solenoid.
An internal transmission problem is also possible.

--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

I had a similar problemthat I just fixed. OD light would glow faintly at times. Then automagically, OD would drop out and light would glow more brightly. Cycling the OD switch on/off would sometimes correct the problem. Sometimes it would re-engage OD, but light would come back glowing faintly. This weekend the OD dropped out and light glowed brightly. No amount of switch cycling would change the OD state. However, when I cycled the switch, I could hear the OD relay click. Pulled the relay and saw that the large lug of the relay frame (ground point of relay?) had a bad solder joint at the circuit board. Resoldered and replaced and all is well.

If the dashboard light goes on and off when you press the shifter button, the shifter switch is OK and probably the OD relay is also. The wire to the OD solenoid may have come off or broken. Please report back and tell us whether you have a manual or automatic transmission and maybe we can help you further.

same thing happened to me in an 84 4speed auto and an 83 manual turbo and a 71 145e auto. all three times all i had to do to fix the prob was to pull out the button and re-solder the connections. or another easy fix is to replace the button altogether. thats a couple dollar junk yard find and it might take care of the prob. in the turbo i had, the vibrations would wiggle the connections loose on the button(which is on the top of the shifter in manuals, or on the side in an auto) and eliminate shifting into overdrive. yeah, scary when it suddenly shifts down and screams like a tree-ed cat!

swarner

"Murky" is the perfect description of which tranny
you are using...4 speed+OD? or 4-speed auto?
Both have dash indicator lights and
shifter buttons. If it's the 4-speed auto-od?
here's a helpful link:
http://www.brickboard.com/RWD/index.htm?id=737816
When my 4-speed-manual+OD failed it was simply the
wire running down the shifter to the solenoid; a
quick easy splice.
Best of Bricking!

Best clue I see is "OD kicked in", which to a user of a 4 speed auto really means OD kicked out to anyone driving a stick. Whatever you do don't tell him to gouge up the solenoid with a dremel...

Just had the same problem two weeks ago. All I had to do was replace the OD relay and everything was great til this morning when I press hard on the gas going uphill and it wouldn't shift to 4th gear. Luckly I had noticed the solenoid wire was having a hard time returning back to normal while I was working on the car. So all I had to do was "tuck" the cable back and walla! Of course thats a temp. fix as far as the cable is concern, I'm shopping for one today! Good Luck!

everything was great til this morning when I press hard on the gas going uphill and it wouldn't shift to 4th gear.

When you "press hard on the gas pedal", you get a "kick-down" from 4th gear (Overdrive) into 3rd gear (Direct drive). So it shifts out of 4th, not in.
The Upshift arrow light is a reminder that you are in 3rd gear, not OD.

Murky is confused on this too. His Overdrive didn't "kick in", it dropped out.

Most often this is due to a broken wire feeding the OD solenoid (no voltage, no OD).
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

I am embarrassed to say that the problem appears to be the automatic transmission fluid level. The Volvo didn't fail, I failed the Volvo.


Thanks for all of the great suggestions. I have in the process learned allot regarding the Overdrive.

Murky