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Q: Does a bad torque converter cause the transmission to not engage into any gear at all?

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My name is Jo, and I have a 95 grand prix SE Coupe with the 3.1L... It has 139000 miles on it and no modifications.. It started to shift erractically a couple of weeks ago 1st to 2nd gear, shuddering at low rpms so I get home to check the fluid in the transaxle and found debris present on the stick but I did not change the fluid since last tune up about 6k prior but the car was still operational so I the next morning I get up for work and start it to warm up come out to leave put it in gear and head to work but turned around cus I forgot my phone pull in the driveway get out while car was at idle but when I get ready to leave it would not engage in any gear at all but did 5 minutes prior. But wen I put it in gear to leave it made a familiar rattling or roaring noise that almost resulted in stalling but it didn't.. I've checked all vacuum hoses for cracks, holes, and leaks there were none with no codes thrown... I've checked fluid level and all sensors are working properly with proper

My car has 139400 miles.
My car has an automatic transmission.

What you are describing may be a result of a faulty speed sensor, potentially low transmission fluid or a even a faulty transmission control solenoid. As your vehicle travels down the road, the computer analyzes data being sent by vehicle speed sensors and engine speed sensors. Based on this information, the Engine Control Unit (ECU), or the Transmission Control Unit (TCM), executes the appropriate upshifts and downshifts by sending a signal to one of several shift solenoids. These transmission solenoids have spring-loaded plungers inside them, which are wrapped with wire. When this coil of wire receives an electrical charge from the TCM / ECU, it causes these plungers to open, allowing transmission fluid to flow into the valve body and pressurize the desired clutches and bands. When this happens, the transmission changes gears and you continue down the road. The computer controls the transmission solenoid in several ways. If the vehicle is equipped with a dedicated Transmission Control Unit, it can open or close the hydraulic circuit using a direct 12v signal. In some cases, the Engine Control Unit (ECU) can control the solenoid’s plunger by turning the ground circuit on and off. When this is not working properly, this can cause a jerking reaction, a delay in shifting or in some cases may cause the transmission to hesitate in shifting gears. I would recommend having a professional from YourMechanic come to your location to diagnose and inspect your transmission.

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