I have a 2000 SL2 that runs and drives great except there is a delay when it shifts from 2nd to 3rd. It takes a long time, usually goes over 4000 rpm then it will jerk slightly once or twice before in goes into third. Every other gear works just fine, and once it gets into third, it stays in. It is worse when climbing a hill .

I tested the solenoids with the cover on and individually across each one and they were all within spec. There was little to no difference in the ohm reading with the cover on so the connections and circuit board should be okay. I bought a new solenoid anyway thinking maybe it was a mechanical fault, aka, not releasing due to a worn or sticking pintle on the solenoid. I replaced the 2nd gear solenoid and it made no difference, so I switched it to the #1 position which is the line pressure solenoid. It helped some, but the problem is still there.

I changed the filter and emptied the old fluid into a clean pan to check for debris, which there was none, and the fluid did not smell burnt so I think the transmission itself is okay mechanically.

I am wondering if I should try putting the new solenoid in the 3rd gear position? Or is there something else I could or should check first, like an input sensor?

Just for reference, it has the 1.9 L engine. I have changed the fuel filter, air filter and serpentine belt. I put new copper-core plugs in but then replaced the iridium plugs that were in the car when I bought it just to make sure what I was feeling was not an engine issue. The engine runs fine in all other gears.

 

moved to appropriate section

 

Did you buy a NEW solenoid or a remanufactured one? Or one from a junkyard? Not nitpicking; answer is very important.

I would move the "new solenoid" to 3rd gear position. Since I find troubleshooting somewhat impossible when changing 2 things at the same time, I would

a) Pull the 3rd gear solenoid and set it aside.
b) Remove the "new" solenoid from the Pressure Control Solenoid spot and place in 3rd gear spot
c) return the ORIGINAL solenoid (that WAS in the Pressure Control Solenoid position BEFORE you replaced it with the new one) to the Pressure Control Solenoid position.

The above yields the exact configuration you had at the beginning + only 3rd gear solenoid being a direct swap for a new one.

The orig press cont solenoid was holding its own for the most part, so putting it back where it was should not cause new problems to arise IMHO.....

If the new one in the 3rd gear position does not solve your problem or only partly solves your problem, the pressure control valve in the valve body itself may be worn and you MAY need to replace the valve body with a rebuilt one. This does not seem terribly likely, just throwing it out there.

There is also always the chance of internal damage that is keeping the 2nd gear clutch from letting go of the band as 3rd tries to engage and the rpms keep rising until 2nd finally lets go (OK, this is a guess---I am past my point of knowledge.)

You will have to drive in the new solenoid for a while (up to 100 mi) for the adaptive learning feature of the transmission/PCM to relearn your shift points.

Also be sure to replace and tighten the input shaft nut on the tranny which works its way loose during repeated slamming events. Replace, do not just retorque unless you want to replace it next year instead. Or maybe 2 yrs from now.......

Saturn TAAT Transmission 3rd. Design Borg-Warner OEM Solenoid 1993-ON (99305) | eBay

Source for supposedly new TAAT solenoids. Note that others DO sell reman solenoids. Not saying reman solenoids are bad, just saying they add another level of unknown.

 

Thanks derf, that was my thought as well and it is not that difficult to do. Interestingly the 3rd gear solenoid showed the lowest resistance at 5.3 ohms. I had originally thought the 2nd gear solenoid was not 'releasing' but perhaps it is the third gear solenoid not 'engaging.' I did purchase a new (not reman) solenoid, I generally do not like using used parts. It came in an AC/Delco box and I did save the old line press solenoid so will try your suggestions. Thanks.

 

and the result was........................................

 

Haven't gotten to it yet, had some other projects I needed to finish first. I am planning on doing it this weekend. I will definitely let you know how it turns out. Thanks again.

 

Moved the new AC Delco solenoid to the 3rd gear position today and put the old line pressure solenoid back in its place. Problem persists. It doesn't shift from 1st to 2nd until 4100-4200 RPM, when it tries to shift from 2nd to third, in "bumps in" two or three times from 4200 - 4800 RPM before it finally engages. This is with average foot pressure on the accelerator. If I really put my foot into it, it will climb to almost 6000 RPM before it shifts.

Again, I considered that it might be another issue so I checked the spark plug wire connections, and tested the secondary coil windings with an ohmmeter. I did not check the primaries, as the engine was too hot to try to remove the plug from the bottom of the ignition coil pack. However I did hook up my OBD II scanner and there are no codes, no misfire signals, EGR and O2 sensors and all other readings that it can read were all good.

I had already tested the solenoids with an ohmmeter individually and through the plug with the harness removed. I had noticed one terminal slightly deformed, although not burnt. It is one of the line pressure solenoids terminals. So, before I disassembled anything I back-probed all the pairs of terminals with the harness installed thinking there might be a faulty connection, but all readings fell within 5.3 - 5.6 ohms. I have done some work on the deformed terminal trying to ensure a tight fit, and if it were loose, it should have shown a higher resistance due to a poor connection.

I guess my next step is to replace the valve body? It seems to drive fine and stay in gear once it gets there, and there are no clutch fragments or metal fragments in the oil so I think the hard parts are all good, and the oil has never smelled burnt. I see reman valve bodies from several transmission rebuilders ranging from about $150.00 on up. Any suggestions?

Would it be worthwhile to hook up a pressure gauge where the pressure sensor is and monitor that while I drive it?

In case anyone asks one of the first things I did was add a transmission fluid additive, but that didn't help either. I am also going to finish testing the ignition system just to make sure I am not chasing the wrong cure.

I do not have any of the other issues I have seen mentioned like slamming into reverse or hard shifting, the rest of the gears are working just fine.

 

You are part of the wonderful minority of TAAT tranny owners to NOT have to deal with that---yet.

I don't know jack when it comes to real transmission repair, but to me it sounds like it either isn't building up enough pressure to shift at the lower rpms or there is some internal slippage starting to occur. Either that or your Transmission control module is confused, but those usually throw P07xx codes.

MAybe Andy can chime in...

 

From what I have read from numerous sources on the i-net, it could well be related to a line pressure issue. When I put the new solenoid in the line pressure slot, it did seem to improve somewhat. The information I have read states that the line pressure valve bore becomes worn, allowing fluid to bypass, causing the low pressure issue. And since it seems to do it mainly when under a load, like climbing a hill, I suspect this might be the issue. The rebuilt units I have been pricing utilize a sleeve inserted into the line pressure bore to prevent wear in the future. There are also kits available for the DIYer, but they are almost as much as purchasing a reman valve body.

If I recall from my automotive school days, it requires more pressure in the lower gears. Once the vehicle gets rolling and the RPMs increase to cruising speed, it takes less pressure to shift to high gear. Indeed it seems my main problem in the 2-3 shift, and once in a while I feel a slight similarity in the 1-2 shift. Once it shifts into 4th, which comes in just like it should, it runs okay, no slippage at all.

As I mentioned there is not a trace of metal or fiber fragments in the oil, so my first indication is that the hard parts, and clutch discs are okay. By the way, I just read that you don't have to drain the oil to change the valve body - wish I had know that!!

I would welcome any comments from others.

 

Just had another thought - does anyone have or know where I can find the pressure spec.s for the TAAT transmission? I could hook up a pressure gauge and try running through the gears and/or driving it and see if there is a pressure drop off or if it is too low.