Lost overdrive
02-02-2010, 07:04 AM
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Lost overdrive
Sometimes my 94 4runner won't shift into overdrive. Normally it shifts when I hit 43 MPH or so. I have been able to get it to shift by taking my foot off the accelerator and putting it in nuetral, letting the RPM's drop and then shifting back to drive. When the engine is cold it takes about a mile or so before the tranny will shift to overdirve. Does vaccum control the shift or is it electronically controlled?
02-02-2010, 07:20 AM
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I know that my wifes Camry wont shift into overdrive until the engine warms up some. Its controlled by the ecu. Now if yours is giving trouble after it warms up, I cant tell you about that.....regards......Rick
02-02-2010, 07:40 AM
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02-02-2010, 07:58 AM
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02-02-2010, 10:33 AM
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That is correct. The cable that goes to the throttle simply increases line pressure as the throttle is opened.
All shifts are controlled by the ECU. The ECU looks at the Throttle Position Sensor and Vehicle Speed Sensors to determine if a downshift or upshift is needed.
As has been mentioned before, the ECU will not allow the tranny to shift into O/D until the engine coolant is warm. This is completely normal. You only have a problem if your truck won't shift into O/D when the engine is completely warm.
All shifts are controlled by the ECU. The ECU looks at the Throttle Position Sensor and Vehicle Speed Sensors to determine if a downshift or upshift is needed.
As has been mentioned before, the ECU will not allow the tranny to shift into O/D until the engine coolant is warm. This is completely normal. You only have a problem if your truck won't shift into O/D when the engine is completely warm.
Last edited by rustypigeon; 02-02-2010 at 10:39 AM.
02-02-2010, 10:45 AM
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I adjusted mine so there is just a touch of slack in it, just enough that I knew it wasn't pulling on it when the throttle was closed. These guys are probably right though that it has nothing to do with kicking you out of OD.
02-02-2010, 03:15 PM
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Does the ECU also look at coolant temp before it will allow you to shift into reverse? I am betting I just have a tranny issue. Thanks for the help.
02-02-2010, 03:46 PM
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02-02-2010, 03:56 PM
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maybe the fluid's just shot and not holding pressures like it should?
have you checked the fluid yet, because I don't see a mentioning of that yet in this thread... is it full? how's it look? if it's dark, than that may be the cause, and a fluid and filter change might just solve all your problems
never overlook the simple things
have you checked the fluid yet, because I don't see a mentioning of that yet in this thread... is it full? how's it look? if it's dark, than that may be the cause, and a fluid and filter change might just solve all your problems
never overlook the simple things
Last edited by iamsuperbleeder; 02-02-2010 at 03:58 PM.
02-02-2010, 04:34 PM
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No I didn't mention the reverse before. It is just an additional little glitch I have been having. This is my daily driver that I paid not too much for. This is my first Yota and I really love it. I am about to buy a 95 4Runner for $1000 from a guy at work, original owner. I am just trying to learn as much as I can about it.
02-03-2010, 10:23 AM
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Not sure how your fluid level is, but if it's too high your o/d may do odd things. After I got a fluid flush, the guys put too much in and my truck would drop out of o/d at highway speeds and seemingly at random regardless of coolant temp.
I drained about a half a quart and the problem went away.
I drained about a half a quart and the problem went away.
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