94 Metro Auto trans stays in Drive gear?

[GM Line Rat]

Hi, My 94 Geo metro W/Auto trans has developed a problem Lately. Sometimes (Not always) after I have started the car and let it warm up, I Drop the trans in R and it drops into gear pretty hard. Then, when I put the car into Drive, The trans starts out in 3rd Gear and wont start in 1st gear like it should. If I shift the trans manually by putting it into 1st or 2nd...It works perfectly with no problems. The trans pulls like it should (No slipping) but in order to drive the car, I Have to shift the trans manually (1st gear, 2nd gear then Drive when I Get up to speed)
BTW, The engine runs great (3 Cyl, 1.0 Liter). Like I Said, sometimes the trans will work like it should, Put it into R and it falls in smooth, put it into Drive and it starts off in 1st gear, 2nd gear then drive and shifts smooth. Other times, I Get the problem described above...
Anyone have a clue as to what might be causing this??? I have a sinking feeling that it's only going to get worse... .....Thanks for any help!!! BTW, Changed the Fluid/Filter in the trans also but it didn't help.....

[hot_sd]

Souns to me like you have two different issues here. The hard engagement in R could be due to high line pressure or overfilling the transmission. You can check the fluid level and see if it is correct.

The missing 1 and 2 gears in the D position sounds to me like you have a problem with the shift control signals from the engine computer, given that you can manually shift into 1 and 2. One of the sensors like the VSS could be faulty or the engine compter itself may be to blame. 1 and 2 are obtained by energizing the second brake and direct clutch solenoids. If they are not energized they stay off closing the 1-2 and 2-3 shift valves giving you 3rd all the time. Inpect the wiring to the shift solenoids (circular connect to the tranny from the engine computer) - make sure it has not come off.

[serenity]

My car displays the same problem almost to the word. The only thing is mine has done it long enough that I have seen a trend. That it will shift first thing just fine if it is fairly warm outside before I start it, if it is cold it takes some time to start shifting. Once it is warmed up well then it will start to shift properly again, but if it is very cold out it takes quite a while to work.

[GM Line Rat]

Originally Posted by hot_sd

Sounds to me like you have two different issues here. The hard engagement in R could be due to high line pressure or overfilling the transmission. You can check the fluid level and see if it is correct.

The missing 1 and 2 gears in the D position sounds to me like you have a problem with the shift control signals from the engine computer, given that you can manually shift into 1 and 2. One of the sensors like the VSS could be faulty or the engine compter itself may be to blame. 1 and 2 are obtained by energizing the second brake and direct clutch solenoids. If they are not energized they stay off closing the 1-2 and 2-3 shift valves giving you 3rd all the time. Inpect the wiring to the shift solenoids (circular connect to the tranny from the engine computer) - make sure it has not come off.

Cool! I'll check the tranny fluid level 1st (Engine warm and in Park) and I'll inspect the wiring for DMG/Loose connections and clean all connections and see if this helps? I Also have a spare 1.0 L Auto trans Engine ECM To try if this doesn't work. BTW, Does the VSS (Vehicle Speed sensor) trip the "Check engine light" or error code if it is faulty or malfunctioning?....Stay tuned and I'll post my results.....Thanks for the help!........Mike

[hot_sd]

Here is a simple thing for both of you to try to see if the problem is in the transmission or in the control system. Disconnect the shift solenoid connector (circular connector on the right going from the engine computer to the transmission). This turns the tranny into a manual - you will get first in L, second in 2 and third in D only. In this mode the shifts are purely controlled by the manual valve. Drive the car as you would a manual. The shift points are normally determined by the ECU using things like the throttle position, vehicle speed etc. There is a table for low throttle and WOT conditions. As I recall if you drive under light throttle you should shift into 2 at about 10mph and third at about 20-25 mph. You can drive under light throttle conditions for the test. If it shifts normally/shows no heat cold variations etc the problem is in the ECU or one or more of the sensors. If the problem is still there it is internal to the transmission and further investigation is needed.

Hope this helps.

[hot_sd]

Yes, a malfunctioning VSS will trip the engine light - P0720 for OBD2. Not sure about cars not using OBD2. Are you getting any codes out. Note that the test I suggested will trip the check engine light. The ECM is clever enough to monitor the volltage drop across the solenoids and if it sees no return current is assumes a broken coil and sets the light as well as an error code.

[GM Line Rat]

Originally Posted by hot_sd

Yes, a malfunctioning VSS will trip the engine light - P0720 for OBD2. Not sure about cars not using OBD2. Are you getting any codes out. Note that the test I suggested will trip the check engine light. The ECM is clever enough to monitor the volltage drop across the solenoids and if it sees no return current is assumes a broken coil and sets the light as well as an error code.

No, The check engine light HAS NOT gone off yet but i'm going to try as suggested and see what happens.....I Believe this car (94) is an OBD-1 Setup. Found the VSS Connector and the Direct Clutch solenoid and 2nd brake solenoid connector on the trans.....I'll post results after I Check it out today........Thanks...........Mike

[GM Line Rat]

[quote=hot_sd]Here is a simple thing for both of you to try to see if the problem is in the transmission or in the control system. Disconnect the shift solenoid connector (circular connector on the right going from the engine computer to the transmission). This turns the tranny into a manual - you will get first in L, second in 2 and third in D only. [quote]

Problem Solved! What I found was that Shift Solenoid Connector on my car had a poor connection in the connector itself. The connector had a small crack in it and Trans fluid/Road dirt etc had gotten caked up in it. The terminals inside the connector were still intact so I Cleaned both ends of the connectors real well with electrical contact cleaner, then sealed the crack with some silicone chaulk. Bought a small piece of "Heat shrink tubing" and once I Reconnected the Shift Solenoid Connector , I Slid the heat shrink tubing over the whole connector and shrank it over the entire connecor to prevent this from happening again....Been driving the car for 3 days now and She shifts just exactly as it's suppose to when dropping it into R, Starts off in 1st like it's suppose to also when you accelerate... ....I'll give it another week or so and if it's still working good.....I'll post back but it appears I've found my problem! BTW, The Shift Solenoid Connector itself is located on the DS Rear of the transmission...White cylinder shaped connector......Thanks Again for all the help!........Mike

[hot_sd]

Glad to help and also to hear that you may have found your problem. Don't understand why it should fix the hard engagement into R since the solenoids are not energized in R - but anyway - if it works then that's great.

[serenity]

Mike I will try to get mine checked this weekend. I'm guessing that my problem is the same as yours and maybe I can finally get it fixed right. Thanks for doing the leg work! S.

[GM Line Rat]

Originally Posted by hot_sd

Don't understand why it should fix the hard engagement into R since the solenoids are not energized in R .

I'm not sure why it did either hot_sd but the only time I ever experienced the "Hard Engagment" , I Also got the problem of the tranny starting out in D instead of 1st gear. Trans fluid level is right where it should be and looks good also! The Hard Engagment reminded me of the "Clunk" you would get when having a bad set of U-Joints on a RWD Vehicle. We have a 93 Metro the I bought for a parts car locally last year that has a complete Manual trans setup in it if the Auto trans in my 94 takes a "Dirt Nap". I'm checking out just how big of a PITA it would be to convert the 94 to a manual trans in the future if I Had too......Any Comments on this?......Thanks again.......Mike

[hot_sd]

Hmm...the hard engagement is a bit of a puzzle - I would like to understand why - with fixing trannies understanding what is going on is half the battle. Normally the only reasons for hard engagement would be - high or misregulated line pressure, debris inside a valve body passage, sticking valve(s), sticking clutch pistons or a fault with one of the four checkballs (not sure which is is used to prime the R valve body passage).

As for conversion to manual - I do not have much knowledge of the manual trans to comment. The things I would check are whether the mounts are in the same place for both and so whether it would fit exactly in place of the auto. The more tricky aprt would be the introduction of a clutch pedal (you could probably buy the parts and mount it inside the car). Also there is an extra cable from the gas pedal to the auto which operates the throttle valve inside the tranny - you will need to get rid of that. You will need to probably get rid of the shift lock system and probably rewire the shift control switch to fool the ecm into thinking it is always in drive. Also if you disconnect the shift solenoid connector you will always have a "check eninge" light on. And you will need to find a way to install the manual shifter - I think there are aftermaket shifters that may make installation easier.

If you plan to do it I think you will need to think it out carefully - I may have missed some thing out.

[GM Line Rat]

Originally Posted by hot_sd

Hmm...the hard engagement is a bit of a puzzle - I would like to understand why - with fixing trannies understanding what is going on is half the battle. Normally the only reasons for hard engagement would be - high or misregulated line pressure, debris inside a valve body passage, sticking valve(s), sticking clutch pistons or a fault with one of the four checkballs (not sure which is is used to prime the R valve body passage).

Yea, the hard shift into R Puzzles me too Hot SD, My gut instinct tells me your probably correct in this assessment of one of the above parts causing the "Hard R" senario. If it returns, I'm going to do an "AutoRX" Treatment to the trans and see if it fixes the problem? I've got all the parts nessasary for a manual swap from the 93 Geo Metro parts car I Have (My Auto trans Metro is a 94) but I'm only looking at this "Last resort" when/If the Auto trans goes in my 94. Some of the items that have to be switched when going to a manual are:
1. Different CV Axles
2. Clutch Pedal, Shifter, Cable and console
3. Clutch resovoir in engine bay area
4. And probably the Engine ECM (For manual trans)
(I'm sure there's more i'm missing)

Even when you add this all up inc Removing the parts out of the 93 (Doing all the labor myself, which I'm capable of).....Dropping $250-300 on a JDM Auto trans sounds like an easier (And less time consuming) alternative, not to mention i'm a stubborn SOB sometimes and would have to install a new Clutch kit, just because it's out of the car and would add to the cost......Stay tuned....I'll update this post if anymore issues occur.......Thanks again for the help Hot SD.......Mike

[hot_sd]

Yep - I'm inclined to agree with your thinking here. To me even pulling out the old tranny and rebuilding it yourself would probably be easier than trying to convert it to a manual. The easiest would be to get another rebuilt tranny and drop it in.

Yes, let us know how you get on.

BTW as for additives - I had a good experince with "Lubegard Red" - after I rebuilt my tranny the shifts were quite hard (I did not service the valve body due to lack of time) and probably some old clutch metarial probably dried out on then and was casuing then to stick. This additive worked great and I have heard good feedback about it on the web as a fix for hard shifts/slipping assuming it is not being caused by something more serious like a damaged seal. If you cannnot get it at your local autoparts store you can buy it online.

[Mr.Corvette]

I have had the same problem with a 94 Metro I bought a few weeks ago. I fixed mine today by tests used in the factory service manual. The TCM (Transmission Control Module) was bad. My module had a burned spot on the circuit board. I repaired a cold solder joint and reinstalled it and it shifts like it should. This module is located to the right of the steering column under the dash. (2) 10MM bolts hold it in place. It has 2 plug in connectors. If you can find a used one it should fix your problem. I understand there were different one used so you will need the numbers on yours for a replacement.