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2001 DTS
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95 Posts
Discussion Starter #1
This '01 DTS won't autoshift into 2nd when D is selected. However it shifts from 1st into 2nd if I start with the selector in 2nd. If I move it to 3rd or D too soon after it shifts to 2nd it tries to drop back down a gear and just revs, not going into any gear until vehicle speed and RPMs command it to go to 3rd wherein it operates normally.

So by starting from a stop with the selector in 2nd am I commanding a different hydraulic circuit? And in moving the selector to 3 or D it commands the usual operating hydraulic circuit? Any thoughts on what the problem here is? Is it still a communication fault between the internal speed sensor and VSS? Because I can change shift solenoids pretty easily if that could be it?
And if this isn't a good location for the post, where would be better, or what forum would be better? Thanks for any info.
 

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2002 Deville and 2009 DTS
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449 Posts
Assuming... check the transmission fluid level first...
Or have you changed the transmission fluid over the years?
How many miles does it have?
 

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Registered
2001 DTS
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95 Posts
Discussion Starter #4 (Edited)
Thanks. I just checked the fluid and it was about a quart low, but no difference in function.
Trans was replaced with a used unit. I talked with the owner who wrecked the car (his was an STS, mine a DTS) and he said it was fine so a local shop installed it. Fresh fluid. Unknown miles, though. Seems like it was 150k-ish.
Talked with several shops. No concensus. The last shop, AMMCO, said it sounds like a communication problem and to check all the pins on the trans connector first to see if one is bent. And try to determine that each pin has a female mate. Someone on another site said a similar thing, that it's a mismatched communication/application.

My orig trans tag: ML
574827


The STS trans tag:
574828
 

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2004 Deville base
'05 SRX N*/AWD, Vetts/Birds/Trucks
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389 Posts
Maybe its a combo of bad electrical/mechanical adjustment/mismatch/??

Almost sounds like wayback when, we got a 4spd hydro linkage backwards, did not know the valve body was 'reversed'
Some excitement and language ensued. Brake pedal was on the wrong side of the steering column as well.
Hot rods/basket cases. no indicator/in gear lockout. Very exciting.haha
 

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Registered
2001 DTS
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95 Posts
Discussion Starter #6 (Edited)
Does anyone know if the connector pin outs line up exactly between STS and DTS? The STS trans might be a 2002. When following the thread here for compatible transmissions, I don't remember seeing anything about that being an issue to tackle. Was hoping the VL and ML data plates might have shed some light on that.

So, it could be an electrical connector mismatch. The trans shop said the controller is commanding a shift as it should when I took them for a test drive. I'd like to take a look for a pin line up between the connectors, a damaged/corroded pin or the possibility of a faulty shift solenoid before totally punting on Northstars like the most of the world has done. I work on a fixed income. Maybe there's a wire broken, which I'll try to look over, too.

EDIT: Oreilly's shows the same auto trans for STS and DTS, but DTS shows 2 options for some reason. T280603 and T280604. STS shows the 2nd only. Maybe VIN related. My car was built 08/2000. 1G6KF57911Uxxxxxx
 

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Alexandra - 96 SDV Clyde - 15 Silvy
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6,357 Posts
Nit sure if the connectors are the same. That being said the STS and the DTS share the same gear ration (3.73:1), so if I know GM like I think I do they should be identical.

I would check connections first to see if there's anything to that, these cars do bizarre stuff when the electricals aren't right.

Glad to see you got it back on the road, I know how much issue you had with getting it rolling. Hopefully the road ahead improves. These are nice cars when they run right.
 

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2001 DTS
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95 Posts
Discussion Starter #8 (Edited)
Thanks, it's been a challenge. Maybe I'll try another car for comparison because I'm surprised that the car isn't as nice as I had always expected. The ride even underwhelmed me. I'm used to driving an 09 equinox which doesn't have a good ride at all, but the drivetrain is perfectly geared for power, even considering it's a Chinese engine. The Northstar engine sound is awesome when you nail it, but not all that exhilarating.

Oh, it's also consuming coolant. White smoke while warming up, which eventually stops but very shortly the check coolant message appears.
 

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2001 DTS
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95 Posts
Discussion Starter #9
The trans installer is going to look at the car in a week or so to try to trace the problem. He said this is something he doesn't run into since so many solenoid related items happen in pairs. Also, I changed my rear tires and the car feels better, but it must have worn struts. Gotta try another DeVille or Seville to compare mine. I'm just fatiguing on this car without a direction to complete tasks.
 

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92 Fleetwood 2dr cpe - FWD, 96 Seville SLS, 02 Seville
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773 Posts
Shift lever controls forward/reverse and releases the new circuit. It also tells the computer the limit of gears via the nss.

The computer controls the fluid flow via the solonoids based on input of current gear, rpm, speed, and desired speed (tps).

There are accumulators they smooth out the shifting. A common problem is the 1-2 accumulator. If it leaks or the spring is broken, 2nd can get harsh, late, non existent.

Try a WOT from stop. The higher fluid pressure can override the leak allowing for a better (but not proper) shift.
 
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