My car is a 1999 Eclipse Spyder 2.4L, automatic transmission

I have a problem with not being able to shift into reverse (it doesn't even act likes it wants to try) or have the trans change gears when in drive. I can let up the gas and then hit it again to get second gear at high rpms (about 3-4k) and it will grab hard enough to chirp the tires... then it might slip into neutral until I slow enough and it will return to 1st or second.

This all worked perfectly fine just a few days ago.. this problem happened all at once a few morning ago.

I am getting a check engine light and a code P1750 which means a bad solenoid.

I dropped the pan, removed the valve body and disassembed everything and checked it all out... no apparent probelms. I did test the solenoids two ways. I gave them 12v power and all clicked. I tested resistance and they all gave proper OHMs.I've reassembled everything and I still have the same problem. I was hoping one was simply hung up.

The only thing I can think of at this point is a bad TCM.

Can a solenoid be not working even though it tests ok?

I would love anybody's input on this.

Thanks! Pete

It is no doubt part of your solenoid assembly. If they all check out, Try to make sure all the electrical connectors and wiring is fine. If it went out instantaneously, this would be my guess.

Are there any fuses for this that may have blown?

Does the TCM seem like a reasonable suspect?

I honestly don't know. I am in no way knowledgeable in automatic trannies.

Sry.

Same with i think about 90% of this forum.

Was there any metal shavings in the oil pan at all?

Sometimes the valvebody will get some trash in it and the valve will not engage all the way. Meaning, your solenoids will try to engage fully, then can't. When they can't, you get funky shifts or popping out of gears, and error codes from the ecu saying bad solenoid.

Pretty much the only codes you will get from any auto tranny are solenoid codes because that's pretty much the only thing that the ecu can monitor. On some cars (not sure about dsm's, it's usually newer cars, and most trucks) there are low fluid sensors and temp sensors.

Try doing a good flush, get a new fluid filter, and go get a bottle of the lucas trans additive when you get your new fluid and see if that works. If not, try to get a new solenoid. And if I were you, I'd be keeping my eye out for a good used tranny.

I guess I'm in that other 10%....

There were some very small flecks of metal in the pan... like glitter sized, but only a few.

All the solenoids tested ok but the TCU or TCM (tranny computer) had some funny readings when tested. I used a voltage meter to check it against a list that tells what voltage should be displayed at each pin under different circumstances. Mainly the pins feeding the solenoids were sending the wrong voltages.

I don't know if I can swap the TCU with any other one that fits from a car with the same trans. If so, I can get one for $40 and try it.

Someone told me that if I unplug all the electrical connections to the trans, I should get reverse again, in fail-safe mode. does this make sense?

What could go internally in the trans to knock out so much at once and also give me the bad solenoid signal on my OBD tester?

I'm pretty sure you can swap the tcu with any other car with the same tranny, meaning any other car like yours, OR any 2nd gen gst or gsx with the auto. \

At least I'm pretty sure it's the same tranny, I know it's the same bolt pattern and mounts, so it's gotta be the same tranny.

And Metal of any size is BAD news.

Try unpluggin the damn thing like you said. I doubt it could do any harm. Then, try the $40 TCU. Then, try doing what I suggested in my last post. If all that fails, you'll either need a new solenoid or a new tranny.

If it's not the solenoid, it can be a number of things. What worries me is that you are having problems with 1st and reverse. In autos, first and reverse are engaged by a band that goes around that portion of the cluster. If that band is messed up and not shifting properly, then you either need to rebuild the tranny quickly before it breaks fully and throws crap all over the guts of your tranny and ruins the entire thing; or buy a new tranny.

It can also be what I said in my last post, it's on its way out and it some metal got into the valvebody and clogged up a valve so the solenoid can't properly actuate it, which would throw the code. Either way, I would keep an eye out for a good used tranny. When you find a good one, buy it and keep it hanging around until you need it so you aren't scrambling around looking for a tranny and get raped on the price.

An auto is a funny piece of equipment. It's pretty much one long cluster of gears with a series of bands wrapped around different sections. Depending on which band is activated, it holds it's section from moving OR realeses it's section to move, and that action changes the gear ratio, thus making it "shift". The fluid is "grippy" to help the bands grip on the clusters. The solenoids push on the valves which open the passage for the fluid to pass through to either pull/push the band open/closed.

Because everything is relatively close together and not really separated that much in the main compartment, it's VERY easy if something gets loose or breaks, to affect the sorrounding parts.