# Automatic sometimes won't shift into 3rd or 4th



## jimaphill (Feb 7, 2004)

Starting a few days ago, my 4-speed automatic 56,000 miles, fluid changed at 36,000) sometimes won't shift into 3rd or 4th but instead stays in 1st and 2nd. When it does this, it shifts into 2nd at almost exactly 4,000 RPM, whether the acceleration is hard or gentle. The shifts feel normal, whether the problem occurs or not.

No OBD II codes, and I feel that the transmission itself is OK but that there's something wrong with an electrical cable or sensor.


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## Shawn (Sep 18, 2002)

Hmmm that bites. Do you drive the car hard? Our trannies are weak as hell, I learned that the hard way.


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## ScAvEnGeR (Jan 28, 2004)

OK... I'm having the same problem as this one and I drove it damn hard... Until the speed cut at 190km/h and 7000 RPM... Any advise???


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## jimaphill (Feb 7, 2004)

Shawn said:


> Hmmm that bites. Do you drive the car hard? Our trannies are weak as hell, I learned that the hard way.


I drive it easy, on flat land, and carry very little load. I think the transmission itself is fine but that the people who removed the engine and transmission (apparently the engine was ruined when it was filled with transmission fluid and then rebuilt) did a bad job reinstalling the electrical cables and routed some of them badly and let some dangle unsupported. 

I thought the problem could be with the vehicle speed sensor, which has one of those dangling cables, but apparently it's used only by the speedometer, not the computer. However I've heard that there's a second speed sensor that reads the motion of the parking pawl teeth, although I haven't been able to find it on the car or any schematic (but I don't have a transmission schematic).


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## lshadoff (Nov 26, 2002)

According to the '97 FSM, a MIL light is not tripped for failure to shift into 3 or 4 if the problem is "...an electrical malfunction (circuits open or shorted) but is a mechanical malfunction such as control valve sticking, improper solenoid valve operation, malfunctioning servo piston or brake band, etc.". The MIL codes are P0703 and P0704.

So, you're right; look for an electrical problem.

Inputs to the A/T control unit are:
O/D OFF indicator
Vehicle speed sensor
Throttle opening from ECM
Engine Speed from ECM
TPS
Inhibitor switch (controls what gear you are in - operated by the shift lever)
Overdrive control switch
A/T fluid temperature sensor
Revolution sensor from trans

Lew


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## BryanC 95SE-R (Mar 24, 2004)

I dont know, but this might be a possibility, but im not mechanically inclined, so i dont value my own opinion on this matter, its jsut a possibility it could be a downshift celanoid or somehing, same thing happend to my dads blazer.
bryan


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## Dego (May 21, 2003)

This might sound stupid, but hell I aint no mechanic eather. I am having simular problem in my Jeep, and I suspect that when I got my oil changed and they topped off my fluids thiey over filled the Trani fluid. I checked my fluids after I noticed the problem and my trani fluid was way over filled. So far I have only noticed it when it is hot out and my transmition shifts fine at first but after driving it for 10 minutes or so, that's when the problem starts. If this aplies then cool, if not sorry for straying a bit.


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## ScAvEnGeR (Jan 28, 2004)

I found the source for my problem... It's just that the auto trans has "spun" some length of the accelerator cable IN so all I did was adjust the cable by pulling a little back out~! SIMPLE 

Our throttle cable is two parts right??? There's the one connected to the pedal then the hub and connects to the tranny right??? The one on the tranny has a little squeeze-to-unlock cable "valve"... Just press down on it and adjust the cable either up or down... Pull more out of the tranny if the shift is at too high rev... But not too much cause if you do then you'll never launch~! Hhahaha....


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## Honestgabes (Sep 10, 2016)

My name is gabe. I'm having the exact problem. How exactly did you fix it. Where is the location on the tranny? Any help would be great.


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