Auto Tranny Problem

I have a 94 Metro auto transmission that has been having a strange tranny problem. When driving it home from work Friday it started to do what I thought was slipping. I would take off from a stop and it wouldn't shift gear but keep reving up until I almost took my foot off the gas and then it would shift. Then when it had to go into the next gear the same thing, I would accelerate the car and it wouldn't shift until I started to take my foot off the gas to keep the engine from overreving. Any ideas anyone? I vaguely remember another car I had a long time ago that did this and it was a vacuum hose to the tranny that was unconnected.

I have a 94 Metro auto transmission that has been having a strange tranny problem. When driving it home from work Friday it started to do what I thought was slipping. I would take off from a stop and it wouldn't shift gear but keep reving up until I almost took my foot off the gas and then it would shift. Then when it had to go into the next gear the same thing, I would accelerate the car and it wouldn't shift until I started to take my foot off the gas to keep the engine from overreving. Any ideas anyone? I vaguely remember another car I had a long time ago that did this and it was a vacuum hose to the tranny that was unconnected.

Hello,

These tranny's use a cable that controls shift pressure. If the cable has broken it will be stuck in "Full Throttle" setting; thus your high rpm shifting. However if your trans feels as if it is slipping... first check your fluid level as per the owners manual.

Blake

Hello,

These tranny's use a cable that controls shift pressure. If the cable has broken it will be stuck in "Full Throttle" setting; thus your high rpm shifting. However if your trans feels as if it is slipping... first check your fluid level as per the owners manual.

Blake

DieInterim, I have a 96 LSI automatic that does not shift up or down.
Ruled out the ecm and the speed sensor on the tranny. The cable that controls shifting that you mention: would that be the shift linkage cable, the oil pressure cable or the interlock cable? Thanks for your attention.
doug

you have a dual cable coming from gas pedal, one goes to throttle and other goes to tranny. find where it is on top of transmission and have someone step on gas with car off a few times and see if cable on tranny is moving smoothly

I think it may have been the cable to the tranny from the gas pedal. I adjusted it tighter and it seems to be OK now when I took it for a short drive around town. The real test will be on Monday when I commute to work. We'll see and keep posted here. Thanks for all of your help.

I think it may have been the cable to the tranny from the gas pedal. I adjusted it tighter and it seems to be OK now when I took it for a short drive around town. The real test will be on Monday when I commute to work. We'll see and keep posted here. Thanks for all of your help.

You know.. cables strech a little over time but they dont do it suddenly unless they are frayed and unraveling. I would treat that cable with suspicion.

Blake

Hey folks,

I have an odd problem as well with my transmission. My car was stored for 9 months (driven a few times) while getting body work and chassis work done. Now that I'm driving it again, this happens:

When accelerating from a stop, the transmission in drive, the car takes of in drive, it does not shift down into 1st, then 2nd and then drive. It just slowly picks up speed in drive. If I manually shift into 1st and then 2nd and then drive, it works just fine. If I'm on the highway and apply the gas the car will not shift down (or into kickdown as we used to call it) -

Has anyone seen this - should I look at the cable mentioned above (I'm a car repair novice for sure)

Kent

Hey folks,

I have an odd problem as well with my transmission. My car was stored for 9 months (driven a few times) while getting body work and chassis work done. Now that I'm driving it again, this happens:

When accelerating from a stop, the transmission in drive, the car takes of in drive, it does not shift down into 1st, then 2nd and then drive. It just slowly picks up speed in drive. If I manually shift into 1st and then 2nd and then drive, it works just fine. If I'm on the highway and apply the gas the car will not shift down (or into kickdown as we used to call it) -

Has anyone seen this - should I look at the cable mentioned above (I'm a car repair novice for sure)

Kent

It would be wise to check the trans. fluid level as well as the cable. Low fluid level will slip clutches and engage improperly.

Hey folks,

I have an odd problem as well with my transmission. My car was stored for 9 months (driven a few times) while getting body work and chassis work done. Now that I'm driving it again, this happens:

When accelerating from a stop, the transmission in drive, the car takes of in drive, it does not shift down into 1st, then 2nd and then drive. It just slowly picks up speed in drive. If I manually shift into 1st and then 2nd and then drive, it works just fine. If I'm on the highway and apply the gas the car will not shift down (or into kickdown as we used to call it) -

Has anyone seen this - should I look at the cable mentioned above (I'm a car repair novice for sure)

Kent

Sounds like the shift signals from the ECU is not getting to the tranny. The PCM controls two shift solenoids (direct clutch and second brake) to generate first and second while in drive. If both solenoids are not energized the tranny will remain in third. I would check the circular connector with as I recall 2 wires and see if it is connected properly. Another possibility is one of the sensors like the VSS. If it is malfunctioning the ECU may not generate the shift signals correctly. Since you can maually shift into first and second it sounds to me like the main parts of the planetary gearset is fine.

Well, the commute to work went great today and the car shifted fine through all gears at the right time. I think the accelerator to tranny cable adjustment did the trick. Thanks for everyone's help on here.

I to have a trany shift problem, I have the 1994 that Shifts Fine when it is cold but as soon as it warms up it does not, I have to mannually shift it. Will not down shift or will not kick into passing gear it just like slips if you try to drop gears and goose it a little. Any Ideas on that one, Maybe the detent cable, Someone told me that there is a computer in the car under the dash that may have condensation and looses connection and may need cleaned.

Tom
Docsplace

I to have a trany shift problem, I have the 1994 that Shifts Fine when it is cold but as soon as it warms up it does not, I have to mannually shift it. Will not down shift or will not kick into passing gear it just like slips if you try to drop gears and goose it a little. Any Ideas on that one, Maybe the detent cable, Someone told me that there is a computer in the car under the dash that may have condensation and looses connection and may need cleaned.

Tom
Docsplace

Need a better description to suggest something with this problem. Does it remain stuck in third while in "D' or does it loose drive when you attempt a downshift. Is downshift the only problem - does it upshift OK.

Very easy to check whether the computer/sensors are to blame - when you have the problem disconnect the shift solenoid connector, put the car into 'D' and measure the voltage - you should see 12V on both lines (both solenoids should be energized).

I have to say that heat related problem usually tends to be due to things inside the tranny like dirty valves. You can try an transmission additive like lubegard and see if it helps - you may have some debris coating the shift valve(s) or the solenoid vent passages to the shift valves causing it to stick when hot. You can also check the cable from the gas pedal to the tranny's throttle valve - if it is out of alignment you could have problems with downshifts if the cable is becoming too slack due to heat (same thing as what the original poster had).

Need a better description to suggest something with this problem. Does it remain stuck in third while in "D' or does it loose drive when you attempt a downshift. Is downshift the only problem - does it upshift OK.

Very easy to check whether the computer/sensors are to blame - when you have the problem disconnect the shift solenoid connector, put the car into 'D' and measure the voltage - you should see 12V on both lines (both solenoids should be energized).

I have to say that heat related problem usually tends to be due to things inside the tranny like dirty valves. You can try an transmission additive like lubegard and see if it helps - you may have some debris coating the shift valve(s) or the solenoid vent passages to the shift valves causing it to stick when hot. You can also check the cable from the gas pedal to the tranny's throttle valve - if it is out of alignment you could have problems with downshifts if the cable is becoming too slack due to heat (same thing as what the original poster had).



It shifts fine downshift and upshifts when its cold, when it warms up it does not do either, If you start out in d when warm it goes but it is in d or 3, I have to down shift it. I can manually shift it but if i try to down shift while warm it just slips unless I am at a slower rpm or speed. I have put a new filter in it and lucas trany fix a week ago and drove it 350mi with no better results.

Thanks
Tom

It shifts fine downshift and upshifts when its cold, when it warms up it does not do either, If you start out in d when warm it goes but it is in d or 3, I have to down shift it. I can manually shift it but if i try to down shift while warm it just slips unless I am at a slower rpm or speed. I have put a new filter in it and lucas trany fix a week ago and drove it 350mi with no better results.

Thanks
Tom

Still not too clear about the "slipping". If you try to downshift and then car keeps going in 3rd then I would suspect an ECU/solenoid issue. If you do feel something happen but the tranny starts slipping/losing drive then I would suspect something inside the tranny.

Since you have already done some basic service the next steps would be - check shift signals from ECU as I suggested as well as TV cable alignmemt. It may be worth just removing and cleanout out the contacts on the connector. If those do not turn up anything it may be time to pull out the valve body, disassemble and service/clean. Luckily for the MX17 tranny the valve body can be removed without having to remove the whole tranny.

Still not too clear about the "slipping". If you try to downshift and then car keeps going in 3rd then I would suspect an ECU/solenoid issue. If you do feel something happen but the tranny starts slipping/losing drive then I would suspect something inside the tranny.

Since you have already done some basic service the next steps would be - check shift signals from ECU as I suggested as well as TV cable alignmemt. It may be worth just removing and cleanout out the contacts on the connector. If those do not turn up anything it may be time to pull out the valve body, disassemble and service/clean. Luckily for the MX17 tranny the valve body can be removed without having to remove the whole tranny.


No it does not keep slipping, If you down shift to 2nd or 1st while moving down the road and try to pass someone it just will not pickup 2nd or first gear, and then slips instead of staying in 3rd, but as soon as you shift back to drive it works fine. All this happens when the trany or car has warmed up, While it is cold when you take off in the mornings especially since this last cold weather we have had in ohio it works normally. Shifts just like it should up and down. ????

I'm not really clear on the dipstick level check either, If I check that first thing in the morning the level is way high, If I check it hot running in neutral it shows normal level. After I drained and dropped the pan I lost about 2 quarts of fluid and put about the same amount back in it.
What is the procedure for checking fluid level, It has 4 notches first 2 Are cold check add and full and the second is hot add and and full, Should I be checking that while trany is hot in neutral??

Thanks for all your help.
Tom
Docsplace

Hello,

These tranny's use a cable that controls shift pressure. If the cable has broken it will be stuck in "Full Throttle" setting; thus your high rpm shifting. However if your trans feels as if it is slipping... first check your fluid level as per the owners manual.

Blake


Blake! I have the same problem mine will not shift when hot but works good when cold.

So I have a question! if that cable controls pressure and the cable is free working the way it is suppose to, could that cable be to tight or loose and would it not give you the correct fluid level reading when the trany is hot?, otherwise it would not raise the fluid level because there is no pressure to foam up the fluid level when it is hot.

Thanks
Tom
Docsplace

Need a better description to suggest something with this problem. Does it remain stuck in third while in "D' or does it loose drive when you attempt a downshift. Is downshift the only problem - does it upshift OK.

Very easy to check whether the computer/sensors are to blame - when you have the problem disconnect the shift solenoid connector, put the car into 'D' and measure the voltage - you should see 12V on both lines (both solenoids should be energized).

I have to say that heat related problem usually tends to be due to things inside the tranny like dirty valves. You can try an transmission additive like lubegard and see if it helps - you may have some debris coating the shift valve(s) or the solenoid vent passages to the shift valves causing it to stick when hot. You can also check the cable from the gas pedal to the tranny's throttle valve - if it is out of alignment you could have problems with downshifts if the cable is becoming too slack due to heat (same thing as what the original poster had).


Ok Checked that voltage on the little white 2-connector from the wire harness that hooks to the top of the trany and I got 1.5vdc on both sides to ground and after a rechecked it a few minutes later there was none, Seems like the warmer it gets the less voltage it produces. that would mean it is in the computer, IS that a seperate control. And just to make sure I checked the right one. Is that the only connector gouing to the trany, I couldn't see any others.

Thanks
Tom

No it does not keep slipping, If you down shift to 2nd or 1st while moving down the road and try to pass someone it just will not pickup 2nd or first gear, and then slips instead of staying in 3rd, but as soon as you shift back to drive it works fine. All this happens when the trany or car has warmed up, While it is cold when you take off in the mornings especially since this last cold weather we have had in ohio it works normally. Shifts just like it should up and down. ????

I'm not really clear on the dipstick level check either, If I check that first thing in the morning the level is way high, If I check it hot running in neutral it shows normal level. After I drained and dropped the pan I lost about 2 quarts of fluid and put about the same amount back in it.
What is the procedure for checking fluid level, It has 4 notches first 2 Are cold check add and full and the second is hot add and and full, Should I be checking that while trany is hot in neutral??

Thanks for all your help.
Tom
Docsplace

In Park. I think your transmission requires thatyou check system pressure. Its cheap and simple and can save you cash. If system pressure is low you need to rebuild/replace. If system pressure is with-in the limits, then I would move on to the Controller.

F.W.I.W.,
Blake

No it does not keep slipping, If you down shift to 2nd or 1st while moving down the road and try to pass someone it just will not pickup 2nd or first gear, and then slips instead of staying in 3rd, but as soon as you shift back to drive it works fine. All this happens when the trany or car has warmed up, While it is cold when you take off in the mornings especially since this last cold weather we have had in ohio it works normally. Shifts just like it should up and down. ????

I'm not really clear on the dipstick level check either, If I check that first thing in the morning the level is way high, If I check it hot running in neutral it shows normal level. After I drained and dropped the pan I lost about 2 quarts of fluid and put about the same amount back in it.
What is the procedure for checking fluid level, It has 4 notches first 2 Are cold check add and full and the second is hot add and and full, Should I be checking that while trany is hot in neutral??

Thanks for all your help.
Tom
Docsplace

When you say downshift do you mean downshifting automatically by pressing the gas pedal or by moving the shift selector down (or both).

Fluid level should be checked when the tranny is hot (after about 15mins of driving ususally). The correct procedure is to do it while the engine is running. Press the brake pedal and then moving the shift selector thru all the ranges starting at "P". Pause for about 2 secs in each range. Fnally return the shift selector back to "P" and then take a reading. This will make sure all the valve body passges are primed and prevent an excessively high reading.

The cold reading will not be very accurate but is there if you quickly want to check the level before driving the car. Very low or no fluid can damage the torque converter and other parts requiring lubrication.

Blake! I have the same problem mine will not shift when hot but works good when cold.

So I have a question! if that cable controls pressure and the cable is free working the way it is suppose to, could that cable be to tight or loose and would it not give you the correct fluid level reading when the trany is hot?, otherwise it would not raise the fluid level because there is no pressure to foam up the fluid level when it is hot.

Thanks
Tom
Docsplace

That cable controls the throttle valve which is used to modify the line pressure under low/high throttle conditions. It is not the primary pressure control - the primary and secondary pressure regulators control the line pressure. The cable tension will not affect your fluid level reading.

Ok Checked that voltage on the little white 2-connector from the wire harness that hooks to the top of the trany and I got 1.5vdc on both sides to ground and after a rechecked it a few minutes later there was none, Seems like the warmer it gets the less voltage it produces. that would mean it is in the computer, IS that a seperate control. And just to make sure I checked the right one. Is that the only connector gouing to the trany, I couldn't see any others.

Thanks
Tom
There should be 2 connectors - a circular one and a square one. The square one should have multiple wires and the circular one two. Not sure why you are getting even 1.5V on the live side - it should be 12V. It looks like you did look at the right one. But yes, if the voltage decays as it gets hotter and you also get shifting problems the problem could be in the computer or one of the sensors. Another easy way to check this would be if you could in some way feed 12V to both the solenoids and see if you can get first and second back. That would confirm the problem.

There should be 2 connectors - a circular one and a square one. The square one should have multiple wires and the circular one two. Not sure why you are getting even 1.5V on the live side - it should be 12V. It looks like you did look at the right one. But yes, if the voltage decays as it gets hotter and you also get shifting problems the problem could be in the computer or one of the sensors. Another easy way to check this would be if you could in some way feed 12V to both the solenoids and see if you can get first and second back. That would confirm the problem.

Just double checked this - actually it should be 2V - not 12V - although 12V is normally used to check solenoids in test mode (and which I have usually done in the past). So 1.5V is below normal to start with and if it goes to zero you may have a faulty TCM. I would remove the wiring harness and check both ends for conneciton problems and also see if all wiring to the TCM is OK.

Just double checked this - actually it should be 2V - not 12V - although 12V is normally used to check solenoids in test mode (and which I have usually done in the past). So 1.5V is below normal to start with and if it goes to zero you may have a faulty TCM. I would remove the wiring harness and check both ends for conneciton problems and also see if all wiring to the TCM is OK.


OK so that TCM is a single module under the dash that those to wires go to?

Thanks
Tom

OK so that TCM is a single module under the dash that those to wires go to?

Thanks
Tom

I guess that should be it. I have a 2000 metro and the control system is different to the older cars. In mine the powertrain control module (PCM) controls both the tranny and the engine. In older cars I believe the 2 are separate. In any event it should be the module that the wiring harness goes from the tranny.

It is very probably that the circuit used to generate the 2V control source may have gone bad. It is probably a voltage reg or a zener type circuit that drops the 12V down to 2V. Sometimes a passive component like a resistor or a cap going bad can start getting worse under changing temperature conditions.

If this is the case the fix should be simple but I'm not sure if the module can be opened and if a circuit diagram of the micro and the support circuity would be available. The more expensive option would be to replace the TCM.

Another thought on how to prove if it is the TCM is to get some freezer spray and chill the module when it is hot and the problem is there and see if the problem goes away. This should prove whether it is the module or something else.

I guess that should be it. I have a 2000 metro and the control system is different to the older cars. In mine the powertrain control module (PCM) controls both the tranny and the engine. In older cars I believe the 2 are separate. In any event it should be the module that the wiring harness goes from the tranny.

It is very probably that the circuit used to generate the 2V control source may have gone bad. It is probably a voltage reg or a zener type circuit that drops the 12V down to 2V. Sometimes a passive component like a resistor or a cap going bad can start getting worse under changing temperature conditions.

If this is the case the fix should be simple but I'm not sure if the module can be opened and if a circuit diagram of the micro and the support circuity would be available. The more expensive option would be to replace the TCM.

Another thought on how to prove if it is the TCM is to get some freezer spray and chill the module when it is hot and the problem is there and see if the problem goes away. This should prove whether it is the
module or something else.


I'll wait till the cold weather hits us again this week, that will tell the tale, I have located a used one for 20.00. If it proves to be the problem. I wonder if there is a way or parts referance to see the mudule number and how many differant geo's or Suzuki's had the same part.

Thanks
Tom

I'll wait till the cold weather hits us again this week, that will tell the tale, I have located a used one for 20.00. If it proves to be the problem. I wonder if there is a way or parts referance to see the mudule number and how many differant geo's or Suzuki's had the same part.

Thanks
Tom
The cold weather will not definitely prove that it is the TCM - just that the cold makes it work better. You can easily pick up a can of freezer spray at an electronics parts place - we use it all the time to debug problems with with the circuits and ICs we design.

The cold weather will not definitely prove that it is the TCM - just that the cold makes it work better. You can easily pick up a can of freezer spray at an electronics parts place - we use it all the time to debug problems with with the circuits and ICs we design.


Looked all over this town for the freeze spray. No one had it, Going to try a can of blowoff, if you turn it upside down it gets cold fast, But i think it is combustable so got to be careful. I'll let you know what the outcome is. Thanks for the help.

Tom
Docsplace

Well it looks like the TCM may be the problem, I used a can of blow off and held the can upside down and sprayed that TCM and it started working after about 30 seconds. It was intermittent off and on for a couple of minutes but it would pick up first gear in drive. I'm going to get that other TCM and try it and hopefully it cures my problem. I will get back with you on this post after I change this out this week and let you know for sure.

Thanks for all your help.
Tom
Docsplace

Hopefully that will fix it and let us know how you get on. $20 is reasonable for a used TCM.