1996 Saturn SL1 OBD reading that 3d and 4 gears failed

1996 SATURN SL1
165,000 MILES • 4 CYL • FWD • AUTOMATIC
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LAURAROUTHEAUX
  • MEMBER
  • 1 POST
I have had issues with my "check engine light coming on and at the same time my car will start shifting very slppy and the RPM's will ramp up.... when I replaced the trasnsmission fluid the light went off and it reversed less harshly then it had in the past. But at that same time when read by a OBD it siad that 3 and 4 gears had failed.... even though it continued to shift smoothly after i replaced the fluid.
Now the light came on again and the same sloppy shifting happened. I added more transmission fluid and the light went off and continued to drive normally. And still the OBD meter is reading the 3 and 4 gears failed.... why is this?"
Sep 21, 2010 at 12:29 PM
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SATURNTECH9
  • CAR REPAIR CONTRIBUTOR
  • 30,869 POSTS
I hope you didn't over fill the transmission fluid you said you added more after you changed it.If your getting a P0733 and a P0734 then most likely you have a pressure issue inside the transmission.3rd and 4th gear clutch pack's take more pressure to engage then 1st and 2nd and reverse take's full line pressure so low pressure is going to effect those gear's.The first thing i would check is your min and max line pressure at idle when it's hot.Then i would remove the valve body and air check the clutches to make sure all the clutch piston's are holding.
Sep 21, 2010 at 12:58 PM
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